ELECTROKINETIC REMEDIATION (EREM2014)
13th
SYMPOSIUM ON ELECTROKINETIC REMEDIATION (EREM 2014) September 7-10, 2014 – Malaga, Spain
Sponsors
University of Malaga
International Society of Electrochemistry
Universidad de Málaga
Campus of International Excellence
Diputación de Málaga
Consorcio Provincial de Residuos Sólidos
Urbanos de Málaga
Consejería de Innovación Ciencia y Empresa
Junta de Andalucía
ELECTROKINETIC REMEDIATION (EREM2014)
Editores
José Miguel Rodríguez Maroto
Rafael García-Delgado
Francisco García-Herruzo
César Gómez-Lahoz
Carlos Vereda-Alonso
María Villén-Guzmán
2014, Málaga, Spain
ISBN - 10: 84-697-0768-X
ISBN - 13: 978-84-697-0768-5
Table of contents
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Table of contents ............................................................................................................. 5
Welcome ........................................................................................................................ 13
Committees .................................................................................................................... 15
Program ......................................................................................................................... 19
Schedule...................................................................................................................... 21
Oral sessions ............................................................................................................... 22
Poster sessions ............................................................................................................ 26
Author index ................................................................................................................. 33
Key lectures ................................................................................................................... 39
Krishna R. Reddy ....................................................................................................... 41
Manuel Rodrigo .......................................................................................................... 43
Oral Session 1: Metal Removal and transport of inorganics ................................... 45
Nº Ref.: O130 ............................................................................................................. 47
Electrodialytic extraction of phosphorus from ash of low-temperature gasification
of sewage sludge
Nº Ref.: O131 ............................................................................................................. 49
Phosphorus recovery and heavy metal removal during municipal wastewater
treatment
Nº Ref.: O140 ............................................................................................................. 51
Electrochemical detection and electroremediation of polluted soil by mercury
using different removing agents
Nº Ref.: O162 ............................................................................................................. 53
Comparison of two experimental set-ups for electrodialytic removal of heavy
metals and Cl from MSWI APC residues
Nº Ref.: O166 ............................................................................................................. 55
Study of electrokinetic remediation technology at semi-pilot scale. Weak acid
enhancement
Oral Session 2: Fundamentals and Modeling ............................................................ 57
Nº Ref.: O209 ............................................................................................................. 59
Modeling of the direct current assisted transport of zero valent iron nanoparticles
Nº Ref.: O232 ............................................................................................................. 61
Influence of 2D physical heterogeneity on the elcetromigration of nitrate
Nº Ref.: O242 ............................................................................................................. 64
Influence of the electrochemical treatment on humic substances content in the
groundwater from limestone aquifers: Preliminary study
Nº Ref.: O243 ............................................................................................................. 65
Enhancement of electro-osmotic flow during the electrokinetic treatment of
contaminated soils
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº Ref.: O261 ............................................................................................................. 67
Electrokinetics to modify strength characteristics of soft clayey soils: A laboratory
based investigation
Nº Ref.: O268 ............................................................................................................. 70
A continuous multi-scale model for ionic transport through electrically charged
membranes
Oral Session 3: Scaling up and field applications ...................................................... 73
Nº Ref.: O313 ............................................................................................................. 75
Pilot scale electrodialytic treatment of MSWI APC residue to decrease leaching of
toxic metals and salts
Nº Ref.: O325 ............................................................................................................. 77
Multivariate analysis of variable importance in the scaling up of electrodialytic
remediation of heavy metals from harbour sediments
Nº Ref.: O326 ............................................................................................................. 79
Design of a pilot electrokinetic remediation plant for marine sediments
contaminated by heavy metals (PROJECT LIFE12 ENV/IT/442 “SEKRET”)
Nº Ref.: O352 ............................................................................................................. 82
Application of solar cell in electrokinetic remediation of As-contaminated soil in
pilot scale
Oral Session 4: Other uses. Miscellaneous. ................................................................ 85
Nº Ref.: O401 ............................................................................................................. 87
A decontamination of the soil contaminated with cesium using electrokinetic-
electrodialytic technology
Nº Ref.: O439 ............................................................................................................. 91
Electrokinetic driven low-acid IOR in Abu Dhabi tight carbonate reservoirs
Nº Ref.: O453 ............................................................................................................. 94
Selective recovery of dissolved metals from acid mine drainage via
electrochemical method
Nº Ref.: O464 ............................................................................................................. 96
Desalination of granite and sandstones by electrokinetic techniques. Comparison
Oral Session 5: Organic and chlorinated organic compounds remediation ........... 99
Nº Ref.: O520 ........................................................................................................... 101
Electrodialytic process applied for phosphorus recovery and organic contaminants
remediation from sewage sludge
Nº Ref.: O523 ........................................................................................................... 103
Integration of electrokinetic process and nano-Fe3O4/S2O82-
process for
remediation of phthalates in river sediment
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Oral Session 6: EKR in combination with other techniques .................................. 105
Nº Ref.: O604 ........................................................................................................... 107
Different strategies to enhance bioremediation of diesel-polluted soils using
electro-kinetic processes
Nº Ref.: O606 ........................................................................................................... 109
Feasibility of coupling permeable bio-barriers and electrokinetic soil flushing for
the treatment of organic chemical polluted soils
Nº Ref.: O608 ........................................................................................................... 112
Effect of electrokinetic enhancement on phytoremediation of soils with mixed
contaminants
Nº Ref.: O634 ........................................................................................................... 114
Potential of electrokinetic process to recover phosphorus and remove cyanotoxins
from membrane concentrate
Nº Ref.: O659 ........................................................................................................... 115
Electrodialytic removal of heavy metals from fly ash from co-combustion of wood
and straw – influence from prewash
Poster Session: Metal Removal and transport of inorganics .................................. 117
Nº Ref.: P110 ............................................................................................................ 119
Remediation of cuprum from clay soils
Nº Ref.: P112 ............................................................................................................ 122
Testing of new shifting current electrodialytic treatment setup for efficient
treatment of Cr-contaminated soil fines
Nº Ref.: P116 ............................................................................................................ 124
Electrokinetic remediation with novel electrode configuration
Nº Ref.: P124 ............................................................................................................ 127
Determining variable importance on electrodialytic remediation of heavy metals
from polluted harbour sediments
Nº Ref.: P127 ............................................................................................................ 129
Monitoring electrokinetics by geophysical methods: Preliminary laboratory
investigations
Nº Ref.: P129 ............................................................................................................ 132
Membrane influence on electrodialytic remediation of air pollution control from
municipal incinerated solid waste
Nº Ref.: P133 ............................................................................................................ 134
Study on removal behavior of cesium ion in clay minerals (kaolin and vermiculite)
by using electrokinetic process
Nº Ref.: P137 ............................................................................................................ 137
Optimization of electrokinetic treatment conditions for a metal-contaminated
dredged sediment
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº Ref.: P145 ............................................................................................................ 140
Effects of electrodialytic process on soil phosphorus
Nº Ref.: P149 ............................................................................................................ 142
Comparison of reagent to enhance desorption and mobility of arsenic in electro-
kinetic remediation from contaminated paddy soil
Nº Ref.: P150 ............................................................................................................ 143
Electrokinetic treatment of dewatered soil cake containing flocculants from soil
washing processes
Nº Ref.: P155 ............................................................................................................ 145
Fibers ion exchange for improvement of electrokinetical removal of heavy metals
from polluted sites
Nº Ref.: P160 ............................................................................................................ 147
Electrical behavior of copper mine tailings during EKR with modified electric
fields
Nº Ref.: P165 ............................................................................................................ 150
Study of electrokinetic remediation technology at semi-pilot scale. Strong acid
enhancement
Nº Ref.: P167 ............................................................................................................ 152
A critical study of the use of the BCR speciation for the characterization of
mobilizable metal contamination
Nº Ref.: P169 ............................................................................................................ 154
Study of efficiency in the removal of lead from soil by different treatments
Nº Ref.: P174 ............................................................................................................ 156
Two step electrodialytic remediation of soil suspension for simultaneous removal
of As and Cu
Nº Ref.: P177 ............................................................................................................ 158
The effects of composting, biosurfactant and freezing-thawing on electrokinetic
removal of heavy metals in sewage sludge
Nº Ref.: P178 ............................................................................................................ 159
The use of 2D non-uniform electric field to remediate chromium-contaminated soil
from an abandoned industrial site with permeable reactive composite electrodes
Poster Session: Fundamentals and Modeling .......................................................... 161
Nº Ref.: P217 ............................................................................................................ 163
Numerical analysis of vanadium and water crossover effects in all-vanadium redox
flow batteries
Poster Session: Scaling up and field applications .................................................... 165
Nº Ref.: P305 ............................................................................................................ 167
The scale up of the flushing-fluid-assisted electrokinetic remediation of kaolin soil
polluted with phenanthrene
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº Ref.: P311 ............................................................................................................ 169
Electrokinetic treatment of polluted soil by gasoline at pilot level couple with an
advanced oxidation process of residual water
Poster Session: Other uses. Miscellaneous. .............................................................. 171
Nº Ref.: P418 ............................................................................................................ 173
Effects of porous properties of carbon felt electrodes on the performance of all-
vanadium redox flow batteries (VRFBs)
Nº Ref.: P419 ............................................................................................................ 175
The effects of hybrid catalyst layer design on methanol and water transport in a
direct methanol fuel cell (DMFC)
Nº Ref.: P428 ............................................................................................................ 177
Electrochemical peroxidation using iron nanoparticles to remove arsenic from
copper smelter wastewater
Nº Ref.: P438 ............................................................................................................ 179
Applying EK to achieve SMART (simultaneous modified assisted recovery
techniques) EOR in carbonate reservoirs of Abu Dhabi
Nº Ref.: P444 ............................................................................................................ 182
Electrochemical degradation of chlorobenzene in water using Pd- catalytic
electro-Fenton’s reaction
Nº Ref.: P447 ............................................................................................................ 183
Hydrodechlorination of TCE by Pd and H2 produced from a copper foam cathode
in a circulated electrolytic column at high flow rate
Nº Ref.: P456 ............................................................................................................ 184
Enhancing electro-Fenton chlorobenzene degradation from groundwater,
oxidation technique in the presence of Pd with different catalyst supports
Nº Ref.: P457 ............................................................................................................ 186
Feasibility of modeling by adsorption the magnetic separation of iron
nanoparticles
Nº Ref.: P458 ............................................................................................................ 189
Electrocoagulation reactor design for arsenic treatment
Nº Ref.: P463 ............................................................................................................ 192
Desalination of sandstone with two different setups under an applied electric field
Nº Ref.: P472 ............................................................................................................ 194
Evaluation of microbial communities, growth rates and susbtrate consumption
under electrical field
Poster Session: Organic and chlorinated organic compounds remediation ......... 195
Nº Ref.: P507 ............................................................................................................ 197
Electrokinetic-Fenton process for remediation of PAHs-contaminated railroad soil
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº Ref.: P515 ............................................................................................................ 200
Characterization and regeneration of Pd/Al2O3 catalyst along a three electrodes
column for chlorobenzene remediation.
Nº Ref.: P535 ............................................................................................................ 202
Removal of a thiazine, an azo and a triarylmethane dyes from dyes polluted
kaolinite by electrokinetic remediation
Nº Ref.: P541 ............................................................................................................ 204
Construction and characterization of dimensional stable anodes with iridium and
tantalium by painting, immersion and electrophoretic deposition for the
electrokinetic treatment of polluted soil by hydrocarbon
Nº Ref.: P573 ............................................................................................................ 206
Enhancing solutions for electrokinetic remediation of dredged sediments polluted
with fuel
Nº Ref.: P576 ............................................................................................................ 208
Electrodescontamination of soils contaminated with dyes for industrial use.
Poster Session: EKR in combination with other techniques .................................. 211
Nº Ref.: P646 ............................................................................................................ 213
Electrochemical dechlorination of TCE with mixtures of humic acid, metal ions
and nitrates in a simulated karst groundwater
Nº Ref.: P651 ............................................................................................................ 214
Comparison on electrokinetics and soil flushing for removal of metals after in-situ
soil mixing
Nº Ref.: P675 ............................................................................................................ 215
Soils contaminated with drugs in common use: An attemp to use the
electroremediation, in combination with the adsorptiom, on industrial waste, as a
prevention tool of contamination.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Welcome
The symposia on Electrokinetic Remediation have been held for more than a decade.
The first was in Albi (France) in 1997, and was followed by eleven more editions that
have spread all around the world: Lyngby, Denmark (1999), Karlsruhe, Germany
(2001), Mol, Belgium (2003), Ferrara, Italy (2005), Vigo, Spain (2007), Seoul, South
Korea (2008), Lisbon, Portugal (2009), Kaohsiung, Taiwan (2010), Utrecht, The
Netherlands (2011), Sapporo, Japan (2012) and finally Boston, USA (2013). All of
them were attended by a diverse audience representing the engineering and scientific
communities with a well-deserved success of participants. We expect to achieve the
same success with the 13th edition of this conference (EREM 2014) in Málaga (Spain)
and that it will continue in the next edition, expected to be held in Abu Dhabi, United
Arab Emirates (2016).
The first editions of this conference were especially focused on the use of electrokinetic
techniques for the remediation of soils contaminated with heavy metals, organic
compounds, radioactive waste, etc. In recent years, there is a growing interest in the
applicability of the electrokinetic techniques in other areas, especially their use in
production processes: water treatment, waste water treatment, mining, food industry,
etc. So, we hope that this edition in Málaga will provide a venue to present and discuss
new research results concerning electrokinetics, which include but do not limit to:
fundamental aspects of electrokinetics, applied research, environmental remediation,
modelling and simulation, combined techniques, etc.
We welcome you to Málaga
Best wishes
José Miguel Rodríguez Maroto
Conference chair
Professor of the Department of Chemical Engineering
University of Málaga
Committees
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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ORGANIZING COMMITTEE
José M. Rodríguez-Maroto (Chairman)
Rafael García-Delgado
Francisco García-Herruzo
César Gómez-Lahoz
Carlos Vereda-Alonso
María Villén-Guzmán
SCIENTIFIC COMMITTEE
Akram N. Alshawabkeh (Northeastern University, Boston, Ma, USA)
Alexandra B. Ribeiro (New University of Lisbon, Portugal)
Claudio Cameselle-Fernández (University of Vigo, Vigo, Spain)
Gordon C.C. Yang (National Sun Yat-Sen University, Taiwan)
Henrik K. Hansen (Technical University Federico Santa María, Valparaiso, Chile)
José M. Rodríguez-Maroto (University of Málaga, Málaga, Spain)
J. P. Gustav Loch (Utrecht University, Utrecht, The Netherlands)
Juan M. Paz-García (Division of soil mechanics, Lund University, Lund, Sweden)
Kitae Baek (Chonbuk National University, Jeonju, Republic of Korea)
Lisbeth M. Ottosen (Technical University of Denmark, Lyngby, Denmark)
Mohamed Haroun (The Petroleum Institute, The United Arab Emirates)
Sibel Pamucku (Lehigh University, Bethlehem, PA, USA)
Program
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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SCHEDULE
Sunday, September, 7th
19:30 – 20:30 Reception/Welcome cocktail
Monday, September, 8th
9:00 – 9:30 Welcome
9:30 – 10:15 Keynote Lecture
10:15 – 10:55 Oral Session 1 (O140, O130)
10:55 – 11:35 Coffee Break/Poster Session
11:35 – 12:35 Oral Session 1 (O131, O162, O166)
12:35 – 13:20 (Invited Speaker)
13:20 – 15:15 Lunch
15:15 – 16:15 Oral Session 2 (O209, O243, O232)
16:15 – 16:55 Poster Session & Coffee.
16:55 – 17:35 Oral Session 2 (O242-O261)
20:00 –
Dinner
Tuesday, September, 9th
9:30 – 9:50 Oral Session 2 (O268)
9:50 – 11:10 Oral Session 3 (O352, O325, O313, O326)
11:10 – 11:50 Coffe break/Poster Session
11:50 – 13:10 Oral Session 4 (O439, O464, O453, O401)
13:10 – 15:15 Lunch
15:15 – 15:55 Oral Session 5 (O523, O520)
15:55 – 16:15 Oral Session 6 (O659)
16:15 – 16:55 Coffe break/Poster Session
16:55 – 17:55 Oral Session 6 (O606, O608, O634)
17:55 – 18:15 Closing session.
Wednesday, September, 10th
10:00 – 13:30 Tour/drink
13:30 – 15:00 Lunch
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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ORAL SESSIONS
Session 1: Metal Removal and transport of inorganics
Monday morning September 8th
Reference: O140
Title: Electrochemical detection and electroremediation of polluted soil by mercury
using different removing agents
Authors: Robles, I., Garcia, J.A., Bustos, E.
Corresponding author: [email protected]
Reference: O130
Title: Electrodialytic extraction of phosphorus from ash of low-temperature gasification
of sewage sludge
Authors: Parés Viader, R., Jensen, P.E., Ottosen, L.M., Hauggaard-Nielsen, H.,
Ahrenfeldt, J.
Corresponding author: [email protected]
Reference: O131
Title: Phosphorus recovery and heavy metal removal during municipal wastewater
treatment
Authors: Ebbers, B., Ottosen, L.M., Jensen, P.E.
Corresponding author: [email protected]
Reference: O162
Title: Comparison of two experimental set-ups for electrodialytic removal of heavy
metals and Cl from MSWI APC residues
Authors: Magro, C., Kirkelund, G.M., Guedes, P., Jensen, P.E., Ottosen, L.M., Ribeiro,
A.B.
Corresponding author: [email protected]
Reference: O166
Title: Study of electrokinetic remediation technology at semi-pilot scale. Weak acid
enhancement
Authors: Villen-Guzman, M., Amaya-Santos, G., Garcia-Rubio, A., Paz-Garcia, J.M.,
Gomez-Lahoz, C., Vereda-Alonso, C.
Corresponding author: [email protected]
Session 2: Fundamentals and Modeling
Monday afternoon September 8th
Reference: O209
Title: Modeling of the direct current assisted transport of zero valent iron nanoparticles
Authors: Gomes, H.I., Rodriguez-Maroto, J.M., Dias-Ferreira, C., Ribeiro, A.B.,
Pamukcu, S.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Reference: O243
Title: Enhancement of electro-osmotic flow during the electrokinetic treatment of
contaminated soils
Authors: Cameselle, C., Gouveia, S.
Corresponding author: [email protected]
Reference: O232
Title: Influence of 2D physical heterogeneity on the elctromigration of nitrate
Authors:Gill, R.T., Harbottle, M.J., Smith, J.W.N., Thornton, S.F.
Corresponding author: [email protected]
Reference: O242
Title: Influence of the electrochemical treatment on humic substances content in the
groundwater from limestone aquifers: Preliminary study
Authors: Rajic, L., Fallahpour, N., Alshawabkeh, A.
Corresponding author: [email protected]
Reference: O261
Title: Electrokinetics to modify strength characteristics of soil: A laboratory based
investigation
Authors: Jayasekera, S.
Corresponding author: [email protected]
Reference: O268
Title: Modeling of ionic transport through charged membranes
Authors: Paz-Garcia, J.M., Villen-Guzman, M., Ristinmaa, M., Rodriguez-Maroto,
J.M.
Corresponding author: [email protected]
Session 3: Scaling up and field applications
Tuesday morning September 9th
Reference: O352
Title: Application of solar cell in electrokinetic remediation of As-contaminated soil in
pilot scale
Authors: Jeon, E.K., Ryu, S.R., Baek, K.
Corresponding author: [email protected]
Reference: O325
Title: Multivariate analysis of variable importance in the scaling up of electrodialytic
remediation of heavy metals from harbour sediments
Authors: Pedersen, K.B., Ottosen, L.M., Jensen, P.E., Lejon, T.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Reference: O313
Title: Pilot scale electrodialytic treatment of MSWI APC residue to decrease leaching
of toxic metals and salts
Authors: Jensen, P.E., Kirkelund, G.M., Dias-Ferreira, C., Ottosen, L.M.
Corresponding author: [email protected]
Reference: O326
Title: Design of a pilot electrokinetic remediation plant for marine sediments
contaminated by heavy metals (project LIFE12 ENV/IT/442 "SEKRET")
Authors: Iannelli, R., Masi, M., Ceccarini, A., Pomi, R., Polettini, A., Marini, A.,
Muntoni, A., De Gioannis, G., Ostuni, M.B., Lageman, R.
Corresponding author: [email protected]
Session 4: Other uses. Miscellaneous.
Tuesday morning September 9th
Reference: O439
Title: Electrokinetic driven low-acid IOR in Abu Dhabi tight carbonate reservoirs
Authors: Ansari, A., Haroun, M., Rahman, M.M., Chilingar, G.V.
Corresponding author: [email protected]
Reference: O464
Title: Desalination of granite and sandstones by electrokinetic techniques. Comparison
Authors: Feijoo Conde, J., Matyščák, O., Ottosen, L.M, Rivas, T.
Corresponding author: [email protected]
Reference: O453
Title: Selective recovery of dissolved metals from acid mine drainage via
electrochemical method
Authors: Park, S.M., Ji, S.W., Baek, K.
Corresponding author: [email protected]
Reference: O401
Title: A decontamination of the soil contaminated with cesium using electrokinetic-
electrodialytic technology
Authors: Kim, G.N., Kim, S.S., Moon, J.K.
Corresponding author: [email protected]
Session 5: Organic and chlorinated organic compounds remediation
Tuesday afternoon September 9th
Reference: O523
Title: Integration of electrokinetic process and nano-Fe3O4/S2O82-
process for
remediation of phthalates in river sediment
Authors: Yang, G.C.C., Chiu, Y.H., Wang, C.L. Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Reference: O520
Title: Electrodialytic process applied for phosphorus recovery and organic
contaminants remediation from sewage sludge
Authors: Guedes, P., Mateus, E.P., Couto, N., Magro, C., Mosca, A., Ribeiro, A.B.
Corresponding author: [email protected]
Session 6: EKR in combination with other techniques
Tuesday afternoon September 9th
Reference: O659
Title: Electrodialytic removal of heavy metals from fly ash from co-combustion of
wood and straw - influence from prewash
Authors: Chen, W., Ottosen, L.M., Jensen, P.E., Kirkelund, G.M., Schmidt, J.W.
Corresponding author: [email protected]
Reference: O606
Title: Feasibility of coupling permeable bio-barriers and electrokinetic soil flushing for
the treatment of organic chemical polluted soils
Authors: Mena, E., Ruiz, C., Saez, C., Villaseñor, J., Rodrigo, M.A., Cañizares, P.
Corresponding author: [email protected]
Reference: O608
Title: Effect of electrokinetic enhancement on phytoremediation of soils with mixed
contaminants
Authors: Chirakkara, R.A., Cameselle, C., Reddy, K. R.
Corresponding author: [email protected]
Reference: O634
Title: Potential of electrokinetic process to recover phosphorus and remove cyanotoxins
from membrane concentrate
Authors: Couto, N., Guedes, P., Mateus, E.P., Santos, C., Teixeira, M.R., Ribeiro, A.B.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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POSTER SESSIONS
Metal Removal and transport of inorganics Reference: P110
Title: Remediation of cuprum from clayey soils
Authors: Romanova, I.V., Korolev, V.A.
Corresponding author: [email protected]
Reference: P112
Title: Testing of new shifting current electrodialytic treatment setup for efficient
treatment of Cr-contaminated soil fines
Authors: Jensen, P.E., Ottosen, L.M., Kirkelund, G.M.
Corresponding author: [email protected]
Reference: P116
Title: Electrokinetic remediation with novel electrode configuration
Authors: Hassan, I, Mohamedelhassan, E, Yanful, E.K.
Corresponding author: [email protected]
Reference: P124
Title: Determining variable importance on electrodialytic remediation of heavy metals
from polluted harbour sediments
Authors: Pedersen, K.B., Ottosen, L.M., Jensen, P.E., Lejon, T.
Corresponding author: [email protected]
Reference: P127
Title: Monitoring electrokinetics by geophysical methods: Preliminary laboratory
investigations
Authors: Masi, M., Ceccarini, A., Ostuni, M.B., Lageman, R., Iannelli, R.
Corresponding author: [email protected]
Reference: P129
Title: Membrane influence on electrodialytic remediation of air pollution control from
municipal incinerated solid waste
Authors: Parés Viader, R., Jensen, P.E., Ottosen, L.M.
Corresponding author: [email protected]
Reference: P133
Title: Study on removal behavior of cesium ion in clay minerals (kaolin and
vermiculite) by using electrokinetic process
Authors: Akemoto, Y., Kitagawa, C., Miyamura, R., Kan, M., Tanaka, S.
Corresponding author: [email protected]
Reference: P137
Title: Optimization of electrokinetic treatment conditions for a metal-contaminated
dredged sediment
Authors: De Gioannis, G., Marini, A., Muntoni, A., Polettini, A., Pomi, R.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Reference: P145
Title: Effects of electrodialytic process on soil phosphorus
Authors: Salvador, N., Gutiérrez, C., Hansen, H., Nunes, L.M., Teixeira, M.R., Jensen,
P.E., Ribeiro, A.B.
Corresponding author: [email protected]
Reference: P149
Title: Comparison of reagent to enhance desorption and mobility of arsenic in electro-
kinetic remediation from contaminated paddy soil
Authors:Ryu, S.R., Jeon, E.K., Baek, K.
Corresponding author: [email protected]
Reference: P150
Title: Electrokinetic treatment of dewatered soil cake containing flocculants from soil
washing processes
Authors: Shin, S.Y., Park, S.M., Baek, K.
Corresponding author: [email protected]
Reference: P155
Title: Fibers ion exchange for improvement of electrokinetical removal of heavy metals
from polluted site
Authors: Belhadj, B, Akretche, D.E., Cameselle, C.
Corresponding author: [email protected]
Reference: P160
Title: Electrical behavior of copper mine tailings during EKR with modified electric
fields
Authors: Rojo, A., Hansen, H., Monárdez, O., Jorquera, C.
Corresponding author: [email protected]
Reference: P165
Title: Study of electrokinetic remediation technology at semi-pilot scale. Strong acid
enhancement
Authors: Villen-Guzman, M., Amaya-Santos, G., Garcia-Rubio, A., Vereda-Alonso,
C., Rodriguez-Maroto, J.M., Paz-Garcia, J.M.
Corresponding author: [email protected]
Reference: P167
Title: A critical study of the use of the BCR speciation for the characterization of
mobilizable metal contamination
Authors: Villen-Guzman, M., Amaya-Santos, G., Garcia-Rubio, A., Paz-Garcia, J.M.,
Garcia-Herruzo, F., Gomez-Lahoz, C.
Corresponding author: [email protected]
Reference: P169
Title: Study of efficiency in the removal of lead from soil by different treatments.
Authors: Villen-Guzman, M., Amaya-Santos, G., Garcia-Rubio, A., Paz-Garcia, J.M.,
Rodriguez-Maroto, J.M., Garcia-Herruzo, F.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Reference: P174
Title: Two step electrodialytic remediation of soil suspension for simultaneous removal
of As and Cu
Authors: Ottosen, L.M., Jensen, P.E., Kirkelund, G.M.
Corresponding author: [email protected]
Reference: P177
Title: The effects of composting, biosurfactant and freezing-thawing on electrokinetic
removal of heavy metals in sewage sludge.
Authors: Luo, Q., Dong, L., Fu, R., Gao, J., Wang, J., Zhang, M..
Corresponding author: [email protected]
Reference: P178
Title: The use of 2D non-uniform electric field to remediate chromium-contaminated
soil from an abandoned industrial site with permeable reactive composite electrodes.
Authors: Fu, R., Xu, Z., Luo, Q., Guo, X.
Corresponding author: [email protected]
Fundamentals and Modeling Reference: P217
Title: Numerical analysis of vanadium and water crossover effects in all-vanadium
redox flow batteries
Authors: Oh, K., Ju, H.
Corresponding author: [email protected]
Scaling up and field applications Reference: P305
Title: The scale up of the flushing-fluid-assisted electrokinetic remediation of kaolin
soil polluted with phenanthrene
Authors: Cañizares, P., López Vizcaíno, R, Risco, C., Saez, C., Rodriguez, L.,
Villaseñor, J., Navarro, V., Rodrigo, M.A.
Corresponding author: [email protected]
Reference: P311
Title: Electrokinetic treatment of polluted soil by gasoline at pilot level couple with an
advanced oxidation process of residual water
Authors: Ramos-Huerta, L., Garibay-Cordero, A., Ochoa-Méndez, B., Pérez-Corona,
M., Cárdenas-Mijangos, J., Bustos, E.
Corresponding author: [email protected], [email protected]
Other uses. Miscellaneous. Reference: P418
Title: Effects of porous properties of carbon felt electrodes on the performance of all-
vanadium redox flow batteries (VRFBs)
Authors: Won, S., Oh, K., Ju, H.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
29
Reference: P419
Title: The effects of hybrid catalyst layer design on methanol and water transport in a
direct methanol fuel cell (DMFC)
Authors: Lee, K, Ferekh, S., Ju, H.
Corresponding author: [email protected]
Reference: P428
Title: Electrochemical peroxidation using iron nanoparticles to remove arsenic from
copper smelter wastewater
Authors: Hansen, H.K., Gutiérrez, C., Rojo, A., Nuñez, P., Valdez, E.
Corresponding author: [email protected]
Reference: P438
Title: Applying EK to achieve SMART (Simultaneous Modified Assisted Recovery
Techniques) EOR in carbonate reservoirs of Abu Dhabi
Authors: Al Kindy, N., Haroun, M., Ansari, A., Chilingar, G.V., Sarma, H.
Corresponding author: [email protected]
Reference: P444
Title: Electrochemical degradation of chlorobenzene in water using Pd- catalytic
electro-Fenton's reaction
Authors: Ciblak, A., Nazari, R., Mousa, I., Alshawabkeh, A.N.
Corresponding author: [email protected]
Reference: P447
Title: Hydrodechlorination of TCE by Pd and H2 Produced from a copper foam cathode
in a circulated electrolytic column at high flow rate
Authors: Fallahpour, N., Yuan, S., Alshawabkeh, A.N.
Corresponding author: [email protected]
Reference: P456
Title: Enhancing electro-Fenton chlorobenzene degradation from groundwater,
oxidation technique in the presence of PD with different catalyst supports
Authors: Mousa, I.E., Alshawabkeh, A.N.
Corresponding author: [email protected], [email protected]
Reference: P457
Title: Feasibility of modeling by adsorption the magnetic separation of iron
nanoparticles
Authors: Lancellotti, F., Retamal, F., Nuñez, P., Hansen, H.
Corresponding author: [email protected]
Reference: P458
Title: Electrocoagulation reactor design for arsenic treatment
Authors: Pineda, D., Nuñez, P., Hansen, H.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Reference: P463
Title: Desalination of sandstone with two different setups under an applied electric field
Authors: Matyščák, O., Feijoo Conde, J., Ottosen, L.M.
Corresponding author: [email protected]
Reference: P472
Title: Evaluation of microbial communities, growth rates and susbtrate consumption
under electrical field
Authors: Zeyoudi, M., Hasan, S.W.
Corresponding author: [email protected]
Organic and chlorinated organic compounds remediation Reference: P507
Title: Electrokinetic-Fenton Process for Remediation of PAHs-contaminated railroad
soil
Authors: Jung, W.S., Lee, J.Y., Cho, Y.M., Yang, J.W.
Corresponding author: [email protected]
Reference: P515
Title: Characterization and regeneration of Pd/Al2O3 catalyst along a three electrodes
column for chlorobenzene remediation.
Authors: Mousa, I.E., Ciblak, A., Nazari, R., Alshawabkeh, A.N.
Corresponding author: [email protected], [email protected]
Reference: P535
Title: Removal of a thiazine, an azo and a triarylmethane dyes from dyes polluted
kaolinite by electrokinetic remediation
Authors: Effendi, Tanaka, S.
Corresponding author: fernando_00id@ yahoo.com
Reference: P541
Title: Construction and characterization of dimensional stable anodes with iridium and
tantalium by painting, immersion and electrophoretic deposition for the electrokinetic
treatment of polluted soil by hydrocarbon
Authors: Herrada, R.A., Medel, A., Manriquez, F., Bustos, E.
Corresponding author: [email protected]
Reference: P573
Title: Enhancing solutions for electrokinetic remediation of dredged sediments polluted
with fuel.
Authors: Rozas, F., Castellote, M.
Corresponding author: [email protected]
Reference: P576
Title: Electrodescontamination of soils contaminated with dyes for industrial use.
Authors: Hernández-Luis, F., Vázquez, M.V., Rodríguez-Raposo, R., Grandoso, D.,
Pérez, M., Ruiz, G., Arbeló, C.D.
Corresponding author: [email protected]
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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EKR in combination with other techniques Reference: P646
Title: Electrochemical dechlorination of TCE with mixtures of humic acid, metal ions
and nitrates in a simulated karst groundwater
Authors: Fallahpour, N., Mao, X, Rajic, L., Yuan, S., Alshawabkeh, A.N.
Corresponding author: [email protected]
Reference: P651
Title: Comparison on electrokinetics and soil flushing for removal of metals after in-
situ soil mixing
Authors: Lee, C.D., Lee, S.W., Jeon, E.K., Baek, K.
Corresponding author: [email protected]
Reference: P675
Title: Soils contaminated with drugs in common use: An attemp to use
electroremediation, in combination with the adsorptiom, on industrial waste as a
prevention tool of contamination.
Authors: Hernández-Luis, F., Vázquez, M.V., Carvajal, E.G., Dévora, S., Abdalá, S.,
Rodríguez-Raposo, R., Martín-Herrera, D., Arbeló, C.D.
Corresponding author: [email protected]
Author index
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
35
Abdalá, S. .................................. P675
Ahrenfeldt, J. ............................. O130
Akemoto, Y. .............................. P133
Akretche, D.E. ........................... P155
Al Kindy, N. .............................. P438
Alshawabkeh, A.N. ................... P515, O242, P444, P646, P447, P456
Amaya-Santos, G. ..................... P165, O166, P167, P169
Ansari, A. .................................. P438, O439
Arbeló, C.D. .............................. P675, P576
Baek, K. ..................................... P149, P150, P651, O352, O453
Belhadj, B .................................. P155
Bustos, E. .................................. P311, O140, P541
Cameselle, C. ............................ O608, O243, P155
Cañizares, P. .............................. O604, P305, O606
Cárdenas-Mijangos, J. ............... P311
Carvajal, E.G. ............................ P675
Castellote, M. ............................ P573
Ceccarini, A. .............................. O326, P127
Chen, W..................................... O659
Chilingar, G.V. .......................... P438, O439
Chirakkara, R.A. ....................... O608
Chiu, Y.H. ................................. O523
Cho, Y.M. .................................. P507
Ciblak, A. .................................. P515, P444
Couto, N. ................................... O520, O634
De Gioannis, G. ......................... O326, P137
Dévora, S. .................................. P675
Dias-Ferreira, C. ........................ O209, O313
Dong, L. .................................... P177
Ebbers, B. .................................. O131
Effendi ....................................... P535
el Din, M.G. .............................. O536
Fallahpour, N. ............................ O242, P646, P447
Feijoo Conde, J. ......................... P463, O464
Ferekh, S. .................................. P419
Fu, R. ......................................... P177, P178
Gao, J......................................... P177
Garcia, J.A. ................................ O140
Garcia-Herruzo, F. .................... P167, P169
Garcia-Rubio, A. ....................... P165, O166, P167, P169
Garibay-Cordero, A. .................. P311
Gill, R.T. ................................... O232
Gomes, H.I. ............................... O209
Gomez-Lahoz, C. ...................... O166, P167
Gouveia, S. ................................ O243
Grandoso, D. ............................. P576
Guedes, P................................... O520, O634, O162
Guo, X. ...................................... P178
Gutiérrez, C. .............................. P428, P145
Hansen, H.K. ............................. P428, P145, P457, P458, P160
Harbottle, M.J. ........................... O232
Harms, H. .................................. O536
Haroun, M. ................................ P438, O439
Hasan, S.W. .............................. P472
Hassan, I .................................... P116
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
36
Hauggaard-Nielsen, H. .............. O130
Hernández-Luis, F. .................... P675, P576
Herrada, R.A. ............................ P541
Iannelli, R. ................................. O326, P127
Jayasekera, S. ............................ O261
Jensen, P.E. ............................... P112, O313, P124, O325, P129, O130, O131, P145, O659,
O162, P174
Jeon, E.K. .................................. P149, P651, O352
Ji, S.W. ...................................... O453
Jorquera, C. ............................... P160
Ju, H. ......................................... P217, P418, P419
Jung, W.S. ................................. P507
Kan, M....................................... P133
Kim, G.N. .................................. O401
Kim, S.S. ................................... O401
Kirkelund, G.M. ........................ P112, O313, O659, O162, P174
Kitagawa, C. .............................. P133
Korolev, V.A. ............................ P110
Lageman, R. .............................. O326, P127
Lancellotti, F. ............................ P457
Lee, C.D. ................................... P651
Lee, J.Y. .................................... P507
Lee, K ........................................ P419
Lee, S.W. ................................... P651
Lejon, T. .................................... P124, O325
López Vizcaíno, R ..................... P305
Luo, Q. ...................................... P177, P178
Magro, C. .................................. O520, O162
Manriquez, F. ............................ P541
Mao, X....................................... P646
Marini, A. .................................. O326, P137
Martín-Herrera, D. .................... P675
Masi, M. .................................... O326, P127
Mateus, E.P. .............................. O520, O634
Matyščák, O. ............................. P463, O464
Medel, A. ................................... P541
Mena, E. .................................... O604, O606
Miyamura, R. ............................ P133
Mohamedelhassan, E ................. P116
Monárdez, O. ............................. P160
Moon, J.K. ................................. O401
Mosca, A. .................................. O520
Mousa, I.E. ................................ P515, P444, P456
Moustafa, A. .............................. O536
Muntoni, A. ............................... O326, P137
Navarro, V. ................................ P305
Nazari, R. .................................. P515, P444
Nunes, L.M. ............................... P145
Nuñez, P. ................................... P428, P457, P458
Ochoa-Méndez, B. .................... P311
Oh, K. ........................................ P217, P418
Ostuni, M.B. .............................. O326, P127
Ottosen, L.M. ............................ P112, O313, P124, O325, P129, O130, O131, O659, O162,
P463, O464, P174
Pamukcu, S. ............................... O209
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Parés Viader, R. ......................... P129, O130
Park, S.M. .................................. P150, O453
Paz-Garcia, J.M. ........................ P165, O166, P167, O268, P169
Pedersen, K.B. ........................... P124, O325
Pérez, M. ................................... P576
Pérez-Corona, M. ...................... P311
Pineda, D. .................................. P458
Polettini, A. ............................... O326, P137
Pomi, R. ..................................... O326, P137
Qin, J. ........................................ O536
Rahman, M.M. .......................... O439
Rajic, L. ..................................... O242, P646
Ramos-Huerta, L. ...................... P311
Reddy, K. R. .............................. O608
Retamal, F. ................................ P457
Ribeiro, A.B. ............................. O209, O520, O634, P145, O162
Risco, C. .................................... P305
Ristinmaa, M. ............................ O268
Rivas, T. .................................... O464
Robles, I. ................................... O140
Rodrigo, M.A. ........................... O604, P305, O606
Rodriguez, L. ............................. P305
Rodriguez-Maroto, J.M. ............ O209, P165, O268, P169
Rodríguez-Raposo, R. .............. P675, P576
Rojo, A. ..................................... P428, P160
Romanova, I.V. ......................... P110
Rozas, F. .................................... P573
Ruiz, C....................................... O604, O606
Ruiz, G. ..................................... P576
Ryu, S.R. ................................... P149, O352
Saez, C....................................... O604, P305, O606
Salvador, N. ............................... P145
Santos, C. .................................. O634
Sarma, H. ................................... P438
Schmidt, J.W. ............................ O659
Shin, S.Y. .................................. P150
Smith, J.W.N. ............................ O232
Tanaka, S. .................................. P133, P535
Teixeira, M.R. ........................... O634, P145
Thornton, S.F. ........................... O232
Valdez, E. .................................. P428
Vázquez, M.V. .......................... P675, P576
Vereda-Alonso, C. ..................... P165, O166
Villaseñor, J. .............................. O604, P305, O606
Villen-Guzman, M. ................... P165, O166, P167, O268, P169
Wang, C.L. ................................ O523
Wang, J. ..................................... P177
Won, S. ...................................... P418
Xu, Z. ........................................ P178
Yanful, E.K. .............................. P116
Yang, G.C.C. ............................. O523
Yang, J.W. ................................. P507
Yuan, S. ..................................... P646, P447
Zeyoudi, M. ............................... P472
Zhang, M. .................................. P177
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Key lectures
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
41
KRISHNA R. REDDY
Future Directions for Electrokinetic Remediation Research
Abstract
In-situ electrokinetic remediation is a
promising technology for the remediation of
difficult subsurface conditions. It is
particularly useful in soils with low
permeability and heterogeneous subsurface
environments where other common
remediation technologies typically fail.
Electrokinetic remediation technology may
also be used to remediate diverse and mixed
contaminants, even when they are non-
uniformly distributed within the subsurface.
The standard electrokinetic remediation method is essentially an electrokinetically
enhanced flushing process. However, electrokinetic remediation may be enhanced or
optimized when integrated or coupled with other proven remediation technologies.
Recently, several successful bench-scale projects have been reported where
electrokinetic remediation was integrated with other technologies. Nevertheless, the
success of electrokinetic remediation technology is dependent on several factors,
including: (1) reliability of the technology; (2) costs of application; (3) practicality of
implementation; (4) application of and ability to meet risk-based remediation goals; (5)
anticipated remediation time; (6) acceptability to project stakeholders; (7) necessity of
special permits; (8) implications on end-use of the site; (9) sustainability considerations,
including triple bottom line parameters; and (10) remediation versus management
paradigm for complex sites. In this presentation, these aspects will be addressed with
respect to future technological innovation and application, the benefits and drawbacks
of its use will be reviewed, and the urgent need for translation of basic research into
actual field applications will be emphasized.
About Dr. Reddy
Krishna Reddy is a Professor of Civil and Environmental Engineering and also the
Director of the Geotechnical and Geoenvironmental Engineering Laboratory (GAGEL)
at the University of Illinois, Chicago, USA. He has over 25 years of teaching,
consulting and research experience focused on contaminated site remediation, waste
management, and sustainable engineering. His research includes laboratory studies,
field experiments, and computer modeling. He has been conducting electrokinetic
remediation for over 18 years. Dr. Reddy is the author of well-known book titled
“Geoenvironmental Engineering: Site Remediation, Waste Containment, and Emerging
Waste Management Technologies” published by John Wiley in 2004. He is also author
of 160 journal papers (with h-index of 35), 10 edited books, 9 book chapters, and over
150 full conference papers. Dr. Reddy has given 129 invited presentations in the U.S.
and 15 other countries (Canada, U.K., Germany, France, Spain, Italy, India, Sri Lanka,
China, Hong Kong, Thailand, South Korea, Japan, Brazil and Colombia). He has served
or currently serves on editorial boards of over 10 different journals. Currently, he is the
Chair of the Geoenvironmental Engineering Committee of Geo-Institute/American
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
42
Society of Civil Engineers and a member of the Environmental Geotechnics Committee
of International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE).
Dr. Reddy has received several awards for excellence in research and teaching,
including the ASTM Hogentogler Award, the University of Illinois Scholar Award, and
the University of Illinois Award for Excellence in Teaching.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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MANUEL RODRIGO
Different strategies to enhance bioremediation of diesel-polluted soils
using electro-kinetic processes
Abstract
In this lecture, different strategies for the
remediation of spiked soils combining
biological processes with electro-kinetic soil
flushing and permeable reactive barriers are
assessed at bench scale in clay and sandy soils
using two-week long treatment tests.
Strategies applied are: 1) Direct combination
of bioremediation with electrokinetic soil
flushing using bicarbonate solution as
flushing fluid 2) single electro-bioremediation
processes with periodic polarity reversal 3)
electrokinetic soil flushing with permeable
reactive bio-barriers using surfactant solutions
as flushing fluids.
Results obtained depend strongly on the type of soil and, as expected, combinations are
only worth for clay soils. In this case, results show that efficiencies obtained with
classical bioremediation are not improved but worsen with the direct combination of
EKSF. These unexpected results are explained in terms of the difficult regulation of pH
and also because of the high temperatures reached at high electric fields (due to the
huge ohmic drops). Both parameters influence negatively on the viability of the
biological culture and finally cause its depletion. In this strategy, temperature also plays
a very important role on results because it favors volatilization of the pollutant. On the
contrary, efficiencies are greatly improved respect to single bioremediation using
permeable reactive bio-barriers consisting of either fixed cultures of acclimated
microorganisms or beds of soil mixed with suspended cultures. In this case, pH
regulation effect is not as dramatic as in the strategy 1 and microorganisms degrade very
efficiently the diesel pollutant. Electro-bioremediation with periodic polarity reversal
also shows good efficiencies avoiding the problems caused by acidic and basic fronts on
microorganisms, although the rates obtained are far below those obtained by bio-
barriers. Changes in the concentration of nutrients, pH, conductivity and temperature are
also analyzed in this work giving light about the ways in which these processes can be
applied at the full scale in a synergistic fashion.
About Dr. Rodrigo
Manuel Rodrigo was born in Plasencia (Spain) in 1970. He studied Industrial Chemistry
at the University of Valencia (1993) and obtained the PhD degree in Chemical
Engineering in the same university in 1997, with a research focused on the development
of automation systems for biological nutrient removal processes. In 1997, he joined the
University of Castilla La Mancha (UCLM), starting a new research line in
Electrochemical Engineering at the Department of Chemical Engineering. In this first
electrochemical stage, his research was focused on the electrolyses of wastewaters
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
44
polluted with organics. After a postdoctoral training in the EPFL (Switzerland), he
started working on electrocoagulation, high temperature PEM fuel cells, oxidants
production, microbial fuel cells and, nowadays, soil electro-remediation (including
bioprocesses). In 2009, he got the position of Full Professor of Chemical Engineering at
the UCLM. He maintains strong consultant collaboration with many companies in
energy and environmental engineering. He is author of more than 200 papers (H=37) in
referenced journal and books, more than 70 technical reports for companies, five
patents, and he has supervised ten doctoral theses. He also has been invited professor in
the Université Paris Est - Marne la Vallée. At present, he is the vice-dean of Chemical
Engineering in the Faculty of Chemical Sciences & Technologies of the University of
Castilla La Mancha and he serves as the Chairman of the Working Party of
Electrochemical Engineering of the European Federation of Chemical Engineering and
Vice-chair of Division 5 Electrochemical Process Engineering and Technology of the
International Society of Electrochemistry.
Oral Session 1: Metal Removal and transport of inorganics
Session Chair:
Alexandra B. Ribeiro
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº REF.: O130
Electrodialytic extraction of phosphorus from ash of low-temperature gasification of sewage sludge
Raimon Parés Viadera*
, Pernille Erland Jensena, Lisbeth M. Ottosen
a,
Henrik Hauggaard-Nielsenb, Jesper Ahrenfeldt
b
a Department of Civil Engineering, Technical University of Denmark, 2800 Kongens
Lyngby, Denmark b Department of Chemical and Biochemical Engineering, Technical University of
Denmark, 4000 Roskilde, Denmark
*Corresponding author: [email protected]
Recirculation of nutrients to agricultural soils is especially important for those produced
from non-renewable resources, such as phosphorous (P) obtained from phosphate rocks.
The reserves of this mineral, mostly located outside the European Union (EU), are
foreseen to be depleted in a range of 100-400 years [1]. In 2012 EU imported 88% of
the phosphate rock consumed. Since only about one fourth of the P applied to
agricultural fields is actually recycled today [2], innovative recycling and re-use
concepts need to be developed and adopted. Low-temperature gasification allows an
energy production from biomass resources with high contents of low melting ash
compounds – often shown to be a source of boiler operational problems in more
traditional incineration. Materials like sludge, have a high P content, which should
preferentially be recycled back to agricultural soils after this thermal process. However,
major concerns are its heavy metal content and the low plant availability of P; hence, a
separation of phosphorus from the bulk bioashes and heavy metals would be beneficial.
P separation can be achieved by acidifying the bioashes in a water solution;
nevertheless, heavy metals will also be released (Figure 1).
Figure 1. pH-desorption of P and Heavy metals in gasified sludge bioashes
In contrast, Electrodialysis (ED) is a technology that allows the mobilization of P from
sewage sludge based bioash materials to aqueous solutions, ensuring its plant
availability as well as separating it from heavy metals. ED was applied to a gasified
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
0 1 2 3 4 5 6 7 8 9
% d
eso
rpti
on
pH
%P
%Cd
%Cr
%Cu
%Ni
%Pb
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
48
sludge with low Fe content, allowing a recovery of around an 80% of the P in a water
solution. Similar experiments were run to a gasified sludge with high Fe content,
showing less encouraging results as the recovery of P was found to be around 30%. For
both ashes, the mass ratio heavy metals/P in the aqueous solution was considerably
lower than in the original material, showing a potential in heavy metals reduction.
References
[1] C.J. Dawson, J. Hilton, Food Policy 36 (2011) S14-S22
[2] D.L. Childers, J. Corman, M. Edwards, J.J. Elser, Bioscience 61 (2011) 117-124
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
49
Nº REF.: O131
Phosphorus recovery and heavy metal removal during municipal wastewater treatment
Benjamin Ebbersa,*
, Lisbeth M. Ottosena, Pernille E. Jenssen
a
a DTU-Byg, Kgs. Lyngby, 2800 Denmark
*Corresponding author: [email protected]
With current and projected consumption rates, primary sources of phosphorus will
rapidly dwindle in the near future and the need for secondary sources will significantly
increase [1]. A high potential secondary resource is sewage sludge; however,
fertilization of agricultural soil using sewage sludge is often impeded by insoluble
phosphorus complexes and hazardous compounds [2], both organic and inorganic of
nature.
The formation of insoluble phosphorus complexes is the result of chemical coagulation,
a common wastewater treatment method. Iron- or aluminum salts are used to precipitate
aqueous phosphorus, mainly present as ortho-phosphates, decreasing phosphorus
mobility and significantly restricting recovery from the sludge at a later stage.
Electrodialysis (ED) has the potential to extract the fraction of aqueous phosphorus,
normally precipitated, during wastewater treatment. Application of ED in a wastewater
treatment plant (WWTP) could eliminate the usage of chemical coagulants altogether.
Furthermore, without chemical coagulation and after incineration, the remaining
phosphorus in the resulting sludge ash will be more readily available for recovery [3].
Whenever heavy metal concentrations exceed legislative standards, for application on
agricultural soil for example, ED can be used to bring heavy metal concentrations below
these limits, allowing the sludge to be applied again.
During preliminary research, the removal rates of both phosphorus and heavy metals in
relationship to general characteristics of wastewater (sludge) using a 3-compartment
(3C) ED cell (figure 1a) was investigated. Samples were obtained from a wastewater
treatment plant in Roskilde during different steps in the treatment process.
The results showed that optimal conditions for extraction of phosphorus or heavy metals
using ED were found at different locations throughout the wastewater treatment process.
Changes in phosphorus removal were mostly influenced by the pH (change) of the
sludge; which in turn was related to the buffer capacity. The removal of heavy metals
depended significantly on the presence of organic matter (OM); where the removal of
heavy metals increased when the amount of OM decreased. Most of the aqueous
phosphorus (present as ortho-phosphate’s) was effectively recovered.
The goal of this study is to continue the development of ED as treatment method to
complement existing wastewater treatment methods and replace chemical coagulation.
In order to create an efficient method, the most important characteristics of wastewater
that influence ED efficiency are investigated. This will be done by subjecting
wastewater and sewage sludge to ED treatment. The wastewater and sludge will be
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
50
obtained during different stages of wastewater treatment from various WWTP’s in
Denmark, employing a variety of wastewater treatment methods, such as oxidative
digestion and enhanced biological phosphorus removal.
Lab experiments are performed using a 2-compartment (2C) ED treatment cell where
the wastewater sludge is separated from the electrode compartments with ion-exchange
membranes. The 2C-setup has shown to significantly improve the heavy metal removal
from iron-rich sewage sludge ashes compared to the 3C-setup [4]. For extraction of
heavy metals, the sewage sludge will be in contact with the anode and the cathode
compartment will be separated by a cation-exchange membrane (figure 1b) while during
extraction of phosphorus the sludge will be in contact with the cathode while the anode
is separated by an anion-exchange membrane (figure 1c).
Figure 1. ED cell setup for (a) 3C setup, (b) 2C extraction of HM’s and (c) 2C extraction of P, with
CAT and AN representing the cation- and anion-exchange membranes, respectively.
The obtained data from this study can be used to asses an optimal placement of ED as
technique to recover phosphorus or remove heavy metals in combination with existing
wastewater treatment methods. Furthermore, correlating ED extraction of phosphorus or
heavy metals against important parameters in the sludge, e.g. organic matter content and
pH, will provide important information for improvement of using ED in these
situations.
References
[1] Cordell, D., Drangert, J.O., White, S.. The story of phosphorus: Global food
security and food for thought. Global Environmental Change, 19, (2009) 292-305.
[2] Miljøministeriet (2012), Miljøstyrelsen, Undersøgelse af PCB, dioxin og
tungmetaller i eksporteret slam til Tyskland, Miljøprojekt nr. 1433, 2012, ISBN
nr. 978-87-92903-32-7.
[3] Matsuo, Y., Release of phosphorus from ash produced by incinerating waste
activated sludge from enhanced biological phosphorus removal. Wat. Sc. Tech.
34, issues 1-2, (1996) 407-415.
[4] Ebbers, B., Ottosen, L.M., Jenssen, P.E., Comparison of two different
Electrodialytic cells for separation of phosphorus and heavy metals from sewage
sludge ash. Chemosphere, submitted (2014).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
51
Nº REF.: O140
Electrochemical detection and electroremediation of polluted soil by mercury using different removing agents
I. Robles, J. A. García, E. Bustos*
Centro de Investigación y Desarrollo Tecnológico en Electroquímica S. C. Parque
Tecnológico Querétaro Sanfandila, Pedro Escobedo, Qro. C.P. 76703.
*Corresponding author: [email protected]
Heavy metals are a large group of elements which are industrially and biologically
important; in consequence they are defined as the group of elements with an atomic
density greater than 6 g cm-3
. Some of these heavy metals are toxic to living organisms
in high concentrations. Heavy metals of greatest concern in terms of human health,
agriculture and ecotoxicology are arsenic (As), cadmium (Cd), lead (Pb), tallium (Tl),
uranium (U) and mercury (Hg). Mercury is one of the most toxic elements to human
health and ecosystem; because of all mercury species are toxic. A wide variety of
mercury species exist in the environment and its various chemical forms can differ in
bioavailability, transport, persistence, and toxicity. Due to high bioaccumulation,
mercury is found on many levels of the food chain. Due to these processes and the high
mobility of mercury species, a good understanding of how mercury species transform
and accurate monitoring are essential for assessing the risk of mercury in the
environment 1.
For the determination of Hg2+
in low concentrations a number of techniques can be
applied, in particular colorimetry and atomic absorption spectrometry. Electrochemistry
provides analytical techniques characterized by instrumental simplicity, moderate cost
and portability; some as stripping methods use a variety of electrochemical procedures
which all share a characteristic initial stage. In Anodic Stripping Voltammetry (ASV),
the electrode behaves as a cathode during deposition and as an anode during
redissolution, where it is oxidized by the analyte again and returns to its original form.
This technique is advantageous to other analytical techniques is its simplicity of use,
low cost of instrumentation, and being monodestructive 1. On other hand, there are
different treatments of polluted soil by mercury as electroremediation, which has been
successfully applied in a variety of soil restoration studies, this methodology having the
advantage of exhibiting simultaneous chemical, hydraulic and electrical gradients.
Indeed, for efficient mercury removal from a saturated soil with electroremediation,
application of either an electric field or direct current through two electrodes (anode and
cathode) is required. These are usually inserted in wells containing a supporting
electrolyte made from inert salts, leading to improved electric field conductive
properties. Specifically, for mercury polluted soil electroremediation, the use of
complexing agents like ethylendiaminetetraacetic acid (EDTA), KI, and NaCl under a
constant potential gradient has been reported 2. Based on the above precedents, the
electroremediation was developed aided by extracting agents for mercury removal from
San Joaquin’s Sierra Gorda soil samples (Figure 1) 3.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
52
Figure 1. Electroremediation process in batch reactor assisted by EDTA (A), and its
corresponding removal percentage of Hg2+ followed during 13 h of treatment, close to anode and cathode.
Electroremediation of mercury polluted soil, facilitated by the use of complexing
agents, proved to be an attractive alternative treatment for the removal of mercury from
polluted soil in mining areas located at Sierra Gorda in Queretaro, Mexico.
Implementation of this remediation protocol is expected to improve the living
conditions and general health of the population in the Mine “El Rincón” in San Joaquin.
Experimental observations suggest that it is possible to remove up to 75 % of metal
contaminants in mercury polluted soil samples by wetting them with 0.1M EDTA,
placing them in an experimental cell equipped with Ti electrodes, and then applying a 5
V electric field for 6 hours. When we followed the electrochemical removal of mercury
in a batch reactor, it was removed around 87% of Hg2+
in a time of 9 hours close to the
anode side by the presence of EDTA. The pH remains nearly constant at 4 and
conductivity showed values close to 10 mS cm-1
by the ionic species. All the mercury
measures were obtained using ASV with a pre-concentration potential –0.6 V vs.
Ag/AgCl, deposition time 6 min, quiet time 30 s, scan rate 20 mV s-1
, obtaining a
detection and quantification limit of 1.47 and 4.89 g L-1
respectively 3.
Finally, the efficient removal of mercury contaminants observed under these conditions
is attributed to electromigration of the coordination complexes that form between the
terminal hydroxyl groups in EDTA and divalent mercury (Hg+2
), which is probably
strengthened by supramolecular interactions between unshared electrons at EDTA’s
tertiary amino nitrogens and Hg+2
. These interactions are particularly effective with the
presence of potassium ions. This observation is supported by molecular modeling of
several possible interactions in the proposed complex using the Density Functional
Theory method (B3LYP LANL2DZ) 1.
References
[1] I. Robles, Luis A. Godínez, J. Manríquez, F. Rodríguez, A. Rodríguez, E. Bustos.
13rd
Chapter from the Book “Soil Pollution”. Ed. In Tech (2014) 379 – 396.
[2] I. Robles, J. Lakatos, P. Scharek, Z. Planck, G. Hernández, S. Solís, E. Bustos.
29th
Chapter from the book “Soil Pollution”. Ed. InTech (2014) 827 – 850.
3 I. Robles, M. G. García, S. Solís, G. Hernández, Y. Bandala, E. Juaristi, E.
Bustos. Intern. J. Electrochem. Sci. 7 (2012) 2276 – 2287.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
53
Nº REF.: O162
Comparison of two experimental set-ups for electrodialytic removal of heavy metals and Cl from MSWI APC residues
Cátia Magroab1
, Gunvor M. Kirkelundb*
, Paula Guedesa, Pernille E. Jensen
b,
Lisbeth M. Ottosenb, Alexandra B. Ribeiro
a
a CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de
Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica,2829-516
Caparica, Portugal b Department of Civil Engineering, Technical University of Denmark, DK-2800 Kgs.
Lyngby, Denmark
*Corresponding author: [email protected]
Air pollution control (APC) residues from municipal solid waste incineration (MSWI) is
classified as hazardous waste and disposed of, although it contains potential resources.
Due to the different flue gas cleaning system designs (wet or semi-dry), APC residues
present distinct chemical and physical characteristics that can influence the remediation
success and their possible reuse [1, 2]. The most problematic elements in MSWI APC
residues are leachable heavy metals and salts. Studies have been made to optimise the
removal of heavy metals from the highly alkaline MSWI APC residues by
electrodialytic remediation in the stirred three compartment set-up (Fig. 1). To obtain
high metal removal assisting agents or long remediation times to acidify the APC
residues are needed [3, 4]. However, assisting agents and significant acidification of the
APC residues drastically changes the properties of the matrix [5]. For reuse purposes,
the aim for remediation should instead be reducing the heavy metal leaching and at the
same time keeping the material characteristics, i.e. keeping the alkaline pH. This is a
new approach for remediating APC residues.
A new two compartment electrodialytic set-up was recently filed for patenting [6]. The
traditional three compartment electrodialytic cell and the new two compartment
electrodialytic cell for treatment of particulate material suspensions are seen in Figure 1.
Figure 1. The experimental set-up of the three and two compartment electrodialytic cell. AN-anion
exchange membrane, CAT-cation exchange membrane.
One of the advantages of the two compartment cell is the insertion of the anode directly
into the suspension that should be treated, leading to faster acidification of the
suspension by the electrode process than the acidification by water splitting at the anion
exchange membrane in the three compartment cell. This would help reduce the
remediation time of the treated material. This work presents a comparison of
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
54
electrodialytic treatment in the two cell set-ups under different experimental conditions,
with the aim of reducing leaching of Cd, Cu, Cr, Pb, Zn and Cl from APC residues, to
facilitate reuse of the APC residues.
Two APC residues were collected from wet and semi-dry flue gas cleaning systems
from Danish waste incineration plants. Sixteen continuously stirred electrodialytic
experiments were made, eight experiments in each cell type. In compartment II and I of
the three and two compartment cell respectively, 100 g APC residue was mixed with
350 ml distilled water, keeping a fixed liquid to solid ratio of L/S 3.5 in all experiments.
Experiments differed in the applied current density (0.1 or 1.0 mA/cm2) and duration (3
or 14 days). Electrical conductivity and pH was measured in the APC residue
suspension daily.
The results show that the pH development in the APC residue suspension was
dependent on the type of APC residue and the experimental cell type, where the
acidification of the suspension occurred earlier when using the two compartment setup
and the acidification of the wet APC residue occurred earlier than for the semi-dry APC
residue. The lowest final pH for the wet and semi-dry APC residues was 6.4 and 10.9,
respectively. To obtain a high net removal of heavy metals from APC residues, lower
pH are needed, however, this is very time consuming [3, 4].
On the other hand, the results obtained from this study showed that the leaching of Cd,
Cu, Pb and Zn were reduced compared to the initial heavy metal leaching from the
untreated residues, except when the pH was reduced to a level below 8 for the wet APC
residues. Cr leaching increased after the electrodialytic treatment. Cl leaching from the
APC residues was less dependent on experimental conditions and was reduced in all
experiments compared to the initial levels.
The results further indicate that the new two compartment cell would be beneficial to
reduce the remediation time for electrodialytic treatment of APC residues prior to
possible reuse.
Acknowledgements
The project FP7-PEOPLE-2010-IRSES-269289-ELECTROACROSS - Electrokinetics
across disciplines and continents: an integrated approach to finding new strategies for
sustainable development and GAP funding from DTU are acknowledged for financing
the study.
References
[1] M.J. Quina, J.C. Bordado, R.M. Quinta-Ferreira, Waste Manage 28 (2008) 2097.
[2] C. Ferreira, A. Ribeiro, L. Ottosen, J Hazard Mater B96 (2003) 201.
[3] A.J. Pedersen, L.M. Ottosen, A. Villumsen, J Hazard Mater B122 (2005) 103.
[4] L.M. Ottosen, A.T. Lima, A.J. Pedersen, A.B. Ribeiro, J Chem Technol
Biotechnol 81 (2006) 553.
[5] A.J. Pedersen, K.H. Gardner, J de Physic IV France, 107 (2003) 1029
[6] L.M. Ottosen, P.E. Jensen, G.M. Kirkelund, B. Ebbers, European patent
application no. 13183278.4 (2013)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
55
Nº REF.: O166
Study of electrokinetic remediation technology at semi-pilot scale. Weak acid enhancement
M. Villen-Guzmana,*
, G. Amaya-Santosa, A. Garcia-Rubio
a, J.M. Paz-Garcia
b, C.
Gomez-Lahoza, C. Vereda-Alonso
a
a Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain
b Division of soil mechanics, Lund University, Lund, 22363, Sweden
*Corresponding author: [email protected]
In another work presented at this conference, titled "Study of electrokinetic remediation
technology at semi-pilot scale. Strong acid enhancement", the results obtained for the
remediation of a soil contaminated by heavy metals are presented. In this case the
enhancement agent is a weak acid solution (acetic acid).
It is well-known that using weak acid presents, besides other advantages, the following:
organic acids are environmentally safe and biodegradable, posses certain buffer
capacities, can behave as complexing agents, and induce small increases in the soil
conductivity [1, 2].
The experimental setup and procedure is the same described in the other paper. The
parameters studied were pH, water content, total metal concentrations (Ca, Cu, Fe, Mg,
Mn, Pb) and BCR fractionation. Besides that, the results obtained in this work were
compared with those obtained from batch extraction experiments together with their
mathematical models.
The experimental results for the acetic acid enhanced experiment at the target values of
pH 4 and 5 are quite similar. Figure 1 shows the percentage of Pb obtained by the BCR
speciation after the soil treatment and for the initial soil. As can be seen the lead related
to the weak acid soluble (WAS) and to the reducible fractions (RED) has been
mobilized in soil close toward the anode compartment by the acid-enhanced technique.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
56
Figure 1. BCR results for the weak acid enhancement of EKR (pH-5)
The results obtained in this work put forward the need of studying lab experiments,
together with mathematics models in order to better understand and predict the behavior
of the remediation techniques at the field-scale.
References
[1] A.T. Yeung, Y.Y Gu. J. Hazard. Mater. 195 (2011) 11.
[2] M. Pazos, S. Gouveia, M.A. Sanromán, C. Cameselle. J. Environ. Sci. Heal. A43
(8) (2008) 823.
Acknowledgements
Authors acknowledge the financial support provided by the Spanish Ministry of
Innovation and the FEDER fund of the EU through the Research Project ERHMES,
CTM2010-16824 and the UE project Electroacross IRSES-GA-2010 269289. Villen-
Guzman also acknowledges the FPU grant obtained from the Spanish Ministry of
Education, Culture and Sport. We also appreciate very much the help of Prof. Carmen
Hidalgo Estevez from the University of Jaen for her advice in the selection and
sampling of the contaminated soils.
0%
20%
40%
60%
80%
100%
120%
140%
160%
180%
Initial 1 2 3 4 5 6 7 8 9 10
% P
b
RES OXI RED WAS
Oral Session 2: Fundamentals and Modeling
Session Chair:
J.P. Gustav Loch
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
59
Nº REF.: O209
Modeling of the direct current assisted transport of zero valent iron nanoparticles
Helena I. Gomesa,b
*, J.M. Rodríguez-Marotoc, Celia Dias-Ferreira
b, Alexandra B.
Ribeiroa, SibelPamukcu
d
aCENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências
e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
bCERNAS – Research Center for Natural Resources, Environment and Society, Escola
Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601
Coimbra, Portugal c Department of Chemical Engineering, University of Málaga, Campus de Teatinos,
29071-Málaga, Spain dDepartment of Civil and Environmental Engineering, Fritz Engineering Laboratory, 13
E. Packer Avenue, Lehigh University, Bethlehem, PA 18015-4729, USA
*Corresponding author: [email protected]
Zero valent iron was used successfully, for more than 20 years, for soil and groundwater
remediation in permeable reactive barriers [1, 2]. Since the late nineties, with the
nanotechnology boom, zero valent iron nanoparticles (nZVI) were considered a
promising step forward due to the possibility of inject them in the contaminated area,
especially for targeting organochlorines in groundwaters [3-7]. However, iron
nanoparticles quickly aggregate and settle, primarily due to magnetic attractive forces
[8]. Results from field scale applications confirm this limited mobility, ranging from
1 m [9] to 6-10 m [10].
One of the methods tested to overcome this poor nZVI mobility was the use of direct
current (DC) [11-15], using the same principles of electrokinetic remediation (EK). In
this method, low-level direct current induces several transport mechanisms and
electrochemical reactions.
In this work, a generalized physicochemical and numerical model has been developed to
describe the nZVI transport through different porousmedia under electric fields. The
model aims to be sufficiently detailed to describe the main processes and also a
predictive tool for the nZVI transport.The model consists in the Nernst–Planck coupled
system of equations, which accounts for the mass balance equation of ionic species in a
fluid medium when diffusion and electromigration are considered in the ions transport
process. In the case of charged particles of nzVI, diffusion and electrophoretic terms
have been taken into account. In both cases, also the electroosmotic flow has included in
the equation. Therefore, the flux of any chemical species or charged particles imoving
from a volume element of the system can be expressed as:
iei*ii
*ii ckcUcDN
(1)
whereci is the molar concentration, *iD is the effective diffusioncoefficient, is the
electrical potential, keis the electroosmoticpermeability coefficient and *iU , is the
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
60
effective electrophoretic mobilityfor nzVI charged particles or ionicmobility, estimated
by the Einstein–Nernst relation for ions.
Two kinds of reactions,electrochemical and chemical, are also included.The rate of
generationterm is not included in the continuity equation for the porous mediumcells
sincewe assume that usually the only electrochemical reactions which need to be taken
into account in the system are the reduction and oxidation of water on the
electrodes.The model has permitted to detect that, in some cases; an important fraction
of the nZVI particles tends to aggregate when their concentration is high relative to the
available pore volume, becoming an immobile iron cake, but the results also indicate
that aggregated mass diminishes clearly in the presence of direct current.
Experimental data using different porosity matrices –ranging from glass beads (with
diameter less than 1 mm, previously sieved) to white Georgia kaolinite clay
(> 2 μm) –, and different electrolytes (10-3
M NaCl, 10-3
M NaOH, 10-1
M Na2SO3 and
0.05 M CaCl2) were used to validate the model.
Acknowledgments
This work has been funded by the European Regional Development Fund (ERDF)
through COMPETE – Operational Programme for Competitiveness Factors (OPCF), by
Portuguese National funds through “FCT - Fundaçãopara a Ciência e a Tecnologia”
under project «PTDC/AGR AAM/101-643/2008 NanoDC», by FP7-PEOPLE-IRSES-
2010-269289-ELECTROACROSS and by the research grant SFRH/BD/76070/2011.
References
[1] USEPA, Permeable Reactive Barrier Technologies for Contaminant Remediation,
National Risk Management Research Laboratory Office of Research and
Development, U. S. Environmental Protection Agency Cincinnati, Ohio 1998.
[2] S. Comba, A. Di Molfetta, R. Sethi, Water Air Soil Poll., 215 (2011) 595-607.
[3] C.B. Wang, W. Zhang, Environ. Sci. Technol, 31 (1997) 2154-2156.
[4] W. Zhang, C.B. Wang, H.L. Lien, Catal. Today, 40 (1998) 387-395.
[5] J. Dries, L. Bastiaens, D. Springael, S.N. Agathos, L. Diels, Environ. Sci.
Technol, 39 (2005) 8460-8465.
[6] Y. Liu, H. Choi, D. Dionysiou, G.V. Lowry, Chem. Mat., 17 (2005) 5315-5322.
[7] H. Song, E.R. Carraway, Environ. Sci. Technol39 (2005) 6237-6245.
[8] T. Phenrat, N. Saleh, K. Sirk, R.D. Tilton, G.V. Lowry, Environ. Sci. Technol, 41
(2007) 284-290.
[9] C.M. Kocur, A.I. Chowdhury, N. Sakulchaicharoen, et al., Environ. Sci. Technol,
(2014) DOI: 10.1021/es4044209.
[10] W. Zhang, D.W. Elliott, Remediation, (2006) 7-21.
[11] H.I. Gomes, C. Dias-Ferreira, A. Ribeiro, S. Pamukcu, Water Air Soil Poll., 224
(2013) 1-12.
[12] H.I. Gomes, C. Dias-Ferreira, A.B. Ribeiro, S. Pamukcu, Chemosphere, 99 (2014)
171-179.
[13] S. Pamukcu, L. Hannum, J.K. Wittle, J. Environ. Sci. Heal. A, 43 (2008) 934-944.
[14] E.H. Jones, D.A. Reynolds, A.L. Wood, D.G. Thomas, Ground Water, 49 (2010)
172-183.
[15] G.C.C. Yang, H.C. Tu, C.H. Hung, Sep. Purif. Technol. 58 (2007) 166-172.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
61
Nº REF.: O232
Influence of 2D physical heterogeneity on the elcetromigration of nitrate
R. T. Gill a,
*, M. J. Harbottle b, J. W. N. Smith
c,a& S. F. Thornton
a
a.Groundwater Protection and Restoration Group, University of Sheffield, Department
of Civil & Structural Engineering, Kroto Research Institute, Sheffield, S3 7HQ, UK b.
Cardiff University, School of Engineering, Queen's Buildings, The Parade. Cardiff,
CF24 3AA, UK c.Shell Global Solutions, Lange Kleiweg 40, 2288 GK Rijswijk, The Netherlands
* Corresponding author: [email protected]
Physical heterogeneity in the subsurface poses significant problems for the
bioremediation of contaminants, these include: (1) delivery of biological amendments to
stimulate bioremediation by hydraulic techniques is limited to soils and sediments with
hydraulic conductivities abovearound 10-7
m s-1
[1]; and (2) physical heterogeneity
imparts controls on the distribution and microscale mixing of microbes and solutes thus
hindering biodegradation [2]. Electrokinetics (EK) is effective at initiating a number of
different transport phenomena in materials with low hydraulic conductivities such as 10-
10m s
-1 [3]. The technique may therefore be suitable at delivering amendments under
physically heterogeneous conditions[4].
The aim of this research is to determine the influence of 2D heterogeneity on the
electromigration of nitrate. The objectives are: (1) to identify whether 2D heterogeneity
imparts controls on the voltage gradient based on differences in the effective ionic
mobility and subsequently the effective electrical conductivity; (2) whether these
voltage gradient differences contribute to enhanced migration between sections of the
2D heterogeneous system; and (3) identify these phenomena in both idealised and
natural sediments.
Electromigration theory indicates that changes in permeability can potentially have an
effect on the mass flux. The description of 1D electromigration mass flux of ionic
species, i is given [5]:
(1)
Where Ji, electromigration mass flux (kg m-2
s-1
); Ci, solute concentration (kg m-3
); uj*,
effective ionic mobility (m2
V-1
s-1
);ke, electroosmotic permeability (m2
V-1
s-1
); E,
electrical potential (V); x, distance (L). The ionic mobility is analogous with the
diffusion coefficient:
(2)
Where ui, ionicmobility (m2
V-1
s-1
); n, porosity (-); τ, tortuosity (-); F, Faraday’s
constant (C mol-1
); zi, valence of ion; Di*, effective diffusion coefficient (L2T
-1); R,
universal gas constant (J K-1
mol-1
); T, absolute temperature (K). The diffusion
coefficient has been shown to decrease with permeability due to an increase in the
tortuosity of the migration path length [6]
. Therefore if the ionic mobility varies spatially
there will also be subsequent variations in the electromigration rate. Similarly, there will
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
62
also bevariation in the voltage gradient based on the relationship between the effective
ionic mobility and the effective electrical conductivity [7]
:
∑
(3)
∑
(4)
Where I, current density (C s-1
m-2
); σ*, effective electrical conductivity (S m-1
). Thus,
in a physically heterogeneous setting where concentration of chemical species is
uniform, the voltage gradient should increase in material with a low effective ionic
mobility (i.e. low permeability material) relative to material with a high effective ionic
mobility (i.e. high permeability material).
Experiments will be conducted in an experimental setup similar to Figure 1. There are
three elements to the experimental design each with associated outcomes:
1. Homogenous vs heterogeneous comparison: homogeneous controls will be run
using the same material type representing the low permeability section in the
heterogeneous experiments. Differences in values for nitrate concentration and
voltage gradient will be used to determine whether nitrate migration between
layers is occurring.
2. Varying nitrate inlet concentration between experiments: this is to increase the
proportionof the amendment in the total electrical conductivity of the electrolyte.
It is expected that the high permeability section will have a higher associated
effective ionic mobility, therefore, the higher the nitrate inlet concentration the
greater the difference in electrical conductivity and voltage gradient between
layers potentially leading to increased migration.
3. Glass beads vs natural sediment: selected homogenous and heterogeneous
experiments will be repeated with natural sediment to observe whether this
phenomena occurs in conditions more representative of the natural environment.
Figure 1. Reactor vessel schematic. Dark and light areas in the sediment chamber show the
zones of low and high permeability X and O represent sampling and voltage probe ports.
References
[1] R.E. Saichek, K.R. Reddy, Surfactant-enhanced electrokinetic remediation of
polycyclic aromatic hydrocarbons in heterogeneous subsurface environments, J.
Environ. Eng. Sci. 4 (2005) 327–339. doi:10.1139/s04-064.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
63
[2] X. Song, E.A. Seagren, In Situ Bioremediation in Heterogeneous Porous Media:
Dispersion-Limited Scenario, Environ. Sci. Technol. 42 (2008) 6131–6140.
doi:10.1021/es0713227.
[3] K.R. Reddy, R.E. Saichek, Effect of soil type on electrokinetic removal of
phenanthrene using surfactants and cosolvents, J. Environ. Eng. 129 (2003) 336–
346. doi:10.1061/(ASCE)0733-9372(2003)129:4(336).
[4] R.T. Gill, M.J. Harbottle, J.W.N. Smith, S.F. Thornton, Electrokinetic-enhanced
bioremediation of organic contaminants: A review of processes and
environmental applications, Chemosphere. 107 (2014) 31–42.
doi:10.1016/j.chemosphere.2014.03.019.
[5] Y.B. Acar, A.N. Alshawabkeh, Principles of electrokinetic remediation, Environ.
Sci. Technol. 27 (1993) 2638–2647. doi:10.1021/es00049a002.
[6] R.K. Rowe, K. Badv, Chloride migration through clayey silt underlain by fine
sand or silt, J. Geotech. Eng. 122 (1996) 60–68. doi:10.1061/(ASCE)0733-
9410(1996)122:1(60).
[7] A.N. Alshawabkeh, Y.B. Acar, Electrokinetic remediation. II: Theoretical model,
J. Geotech. Eng. 122 (1996) 186–196. doi:10.1061/(ASCE)0733-
9410(1996)122:3(186).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
64
Nº REF.: O242
Influence of the electrochemical treatment on humic substances content in the groundwater from limestone aquifers: Preliminary study
Ljiljana Rajic*, Noushin Fallahpour, Akram Alshawabkeh
Civil and Environmental Engineering Department, Northeastern University, Boston,
MA, 02115, USA
*Corresponding author: [email protected]
Groundwater natural organic matter (NOM), and its interactions with carbonate aquifer
constituents, may play an important role in controlling subsurface processes by acting as
a proton donor and acceptor and as a pH buffer, by influencing mineral precipitation
and dissolution, and by affecting the transport and degradation of pollutants [1]. In this
study we investigated the influence of electrochemical treatment on humic substances
(HS) content in the simulated groundwater from limestone aquifers. The treatment was
conducted by cathode→anode electrode arrangement in electrochemical flow-through
reactor column filled with limestone gravel. Total organic carbon (TOC) and dissolved
organic carbon (DOC) decreased 50.2% and 44.7%, respectively, after the simulated
groundwater flow through column reactor without current application. This indicates
HS adsorption on the limestone gravel under the tested conditions. After
electrochemical treatment there was a significant TOC (92.8%) and DOC (58.0%)
decrease which indicates the electrochemical transformation of HS. We also
investigated an impact of HS presence on the electrochemical trichloroethylene (TCE)
degradation. TCE electrochemical removal efficiencies were: 31.9% in the absence of
HS and 33.6%, 31.9% and 32.5% in the presence of 1 ppm, 5 ppm and 10 ppm TOC
from HS, respectively. The results indicate that electrochemical treatment affects HS
content in groundwater but there is no influence of HS on the electrochemical TCE
removal efficiency.
References
[1] J. Jin, A.R. Zimmerman, Appl. Geochem. 25 (2010) 472
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
65
Nº REF.: O243
Enhancement of electro-osmotic flow during the electrokinetic treatment of contaminated soils
Claudio Cameselle*, Susana Gouveia
Department of Chemical Engineering, University of Vigo. 36310-Vigo (Spain)
*Corresponding author: [email protected]
Electro-osmosis is one of the main transportation mechanisms for contaminant removal
in the electrokinetic remediation of contaminated soils. Electro-osmosis can be defined
as the net flux of water towards one of the electrodes induced by the electric field. The
electro-osmosis flow depends on fluid characteristics (dielectric constant and viscosity)
and soil surface characteristics represented by the Zeta potential, as well as the voltage
gradient. Zeta potential is a function of many parameters including the chemical nature
of the soil particles, pH, temperature and ionic strength of the interstitial fluid. Some of
these parameters are affected by the electrokinetic treatment itself. The soil pH and the
type and concentration of ions in the interstitial fluid change during the electrokinetic
treatment of a contaminated soil due to the chemical reactions and the transportation
induced by the electric field. Those changes clearly affect the development and the
maintenance of a high electro-osmotic flow.
The aim of this work is to determine the influence of electrochemical variables in the
development and maintenance of electro-osmotic flow with the objective to determine
the best operating conditions for the treatment of soil contaminated with mixtures of
organic and inorganic contaminants.
An agricultural soil with a high content of organic matter was used in this study. The
soil was contaminated with heavy metals (Cd, Co, Cr, Cu, Pb, Zn) and PAH
(Anthracene and Phenanthrene). Six experiments were carried out in a cylindrical
electrokinetic cell to determine the influence in the electro-osmotic flow of the pH,
voltage gradient, and the use of facilitating agents on anolyte and catholyte. Three
organic acids: citric, oxalic and tartaric acid were used as facilitating agents to improve
metal removal, but at the same time, to improve the electro-osmotic flow and control
the pH on the electrode chambers.
Figure 1. Accumulated electro-osmotic flow as a function of the applied voltage in the
electrokinetic treatment of an agricultural soil.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
66
Figure 1 shows the influence of the voltage on the electro-osmotic flow (EOF) of a
sample of the agricultural soil. Tap water was used in both electrode chambers and no
pH control was used during the first 27 days of operation. After the first week, where a
minor electro-osmotic flow was collected at the cathode, a very different behavior was
observed based on the applied voltage. A voltage of 20 V, which corresponds with
1 V/cm, resulted in a continuous EOF whereas the experiment at 30 V showed no EOF.
The experiment at 10 V showed an intermediate value. After 27 d of operation, the pH
on the anode was kept alkaline with periodic addition of NaOH and the catholyte was
acidify with periodic addition of sulfuric acid. Surprisingly, the experiments at 20 and
10 V did not showed any variation in the EOF after the pH shift, but an increasing EOF
was detected in the experiment at 30 V. These results can be related to the pH into the
soil due to the control of pH in the catholyte and anolyte.
Figure 2 shows the accumulated electro-osmotic flow when citric, oxalic and tartaric
acid where used in the anolyte in the electrokinetic treatment of a soil sample at
constant voltage: 20 V. These acids may enter the soil transported by electro-osmosis,
but this transportation is limited by the electromigration of the anions in the opposite
direction, towards the anode. Despite of the opposite transportation of citrate, oxalate
and tartrate by electromigration and electro-osmosis, very different EOF was observed
when organic acids were used compared to the results of experiment at 20 V in figure 1.
Moreover, the effect of each organic acid in the EOF was very different. Citric and
tartaric acid resulted in a continuous EOF, whereas oxalic acid showed a very fast flow
in the very beginning and then the flow stopped. During the first 27 days, the pH in the
anode tend to be very acidic and on the cathode very alkaline. On day 27th
NaOH and
the corresponding organic acid were used to acidify the cathode and to increase the pH
on the anode. After the pH shift the behavior was even more surprising. The EOF in the
experiments with citric and tartaric acid stopped and a significant EOF was detected on
the anode. The experiment with oxalic acid showed a significant EOF towards the
cathode. This results can be related with the soil pH affected by the pH in the electrode
chambers, and what is more important, the EOF is affected by the interaction of citrate,
oxalate and tartrate with the soil particles, changing the surface characteristics, the zeta
potential, and therefore the EOF.
Figure 2. Accumulated electro-osmotic flow using citric, oxalic and tartaric acid in anolyte and
catholyte in the electrokinetic treatment of an agricultural soil.
References
[1] C. Cameselle, K.R. Reddy, Electrochim. Acta 86 (2012) 10.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
67
Nº REF.: O261
Electrokinetics to modify strength characteristics of soft clayey soils: A laboratory based investigation
Samudra Jayasekeraa*
a Faculty of Science, School of Science, Information Technology & Engineering,
Federation University of Australia, Ballarat 3350, Australia
*Corresponding author: [email protected]
The use of electrokinetic (EK) methods is a viable in situ soil remediation and treatment
technique that is being researched in many parts of the world and currently being
practised successfully in some parts of the Europe and US. EK processing significantly
alters many physicochemical properties of soil porous media. Although there is a
considerable amount of literature available reporting the changes in chemistry of porous
media with EK processing, only limited studies have investigated changes in soil
physical properties, particularly strength characteristics with EK processing.
In this study, the effects of EK processing on compressive strength characteristics of
two types of soils were investigated using laboratory experimental models. Soils were
collected from soft alluvial soil deposit (Soil S1) and basaltic soil deposit (Soil S2) in
central Victoria, Australia. A layer of soil was placed in glass tanks (900mm×350mm
plan area) and compacted to a known density and water content typical of field
conditions. Using electrodes inserted into the soil, a direct current was passed across the
soil under various voltage gradients (0.5, 1, 2V/cm) for period of 7, 14 and 30 days.
Unconfined compression (UC) tests and pocket penetrometer tests were conducted on
original soils and EK processed soils.
From the UC and penetration test results (Table 1) it is noted that, soil compressive
strength increases with the increasing processing time and increasing voltage gradients,
at various rates. Under certain voltage gradients and processing times, around 175% and
200% strength increases are observed. In general, stress increases of at least 30% or
more are reported for both soils under all test conditions.
It is apparent that the variation in strength can be attributed to several complex and
interrelated processes that become active under EK processing [1, 2, 3]. These may
include, (i) Electroosmotic advection - When a soil is subjected to EK processing with
an open electrode configuration, the water content of the soil varies predominantly due
to the electroosmotic advection while natural drying and evaporation could also add to
the decrease in water content to some extent, depending on the time and environmental
conditions such as temperature and humidity [2, 3]. The test results show that with the
decrease in water content, there is a corresponding increase in the strength. (ii)
Electromigration - The electromigration of charged ions and their interaction with clay
minerals can also affect the soil strength due to the variations in the DDL ionic
concentration and subsequent modifications in the soil structure [1]. (iii) Ionic Diffusion
and Aging - After the complete termination of EK processes, the ionic concentrations
still continued to modify at a slower rate. This is considered to be due to the ionic
diffusion. In this phase too, cementation bonds may continue to develop that could
contribute to the increase in soil strength. During this period, two other processes, i.e.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
68
natural drying of soil and aging [4] may continue that can also affect the variation of
soil strength.
Table 1. Variation of maximum axial stress at cathode and anode positions for soil S1 and S2 with increasing voltage gradients and EK processing time durations
Soil
type
Treatment
duration
(days)
Voltage
Gradient
(V/cm)
Cathode Anode
Stress
kN/m2
Stress
increase
%
Stress
kN/m2
Stress
increase
%
S1
Untreated 37- 42
7
0 40 5.3 33 -13.2
0.5 50 31.6 44 15.8
1 59 55.3 54 42.1
2 63 65.8 51 34.2
14
0 44 15.8 34 -10.5
0.5 65 71.1 47 23.7
1 72 89.5 56 47.4
2 82 115.8 52 36.8
30
0 47 23.7 41 7.9
0.5 70 84.2 56 47.4
1 81 113.2 58 52.6
2 104 173.7 60 57.9
S2
Untreated 95 - 104
7
0 106 9.3 88 -9.3
0.5 105 8.2 151 55.7
1 178 83.5 166 71.1
2 208 114.4 192 97.9
14
0 116 19.6 88 -9.3
0.5 163 68.0 213 119.6
1 124 27.8 246 153.6
2 246 153.6 287 195.9
30
0 141 45.4 105 8.2
0.5 185 90.7 222 128.9
1 164 69.1 262 170.1
2 264 172.2 303 212.4
References
[1] Acar, Y. B., Hamed, J. T., Alshawabkeh, A. N., and Gale, R. J. (1994). "Removal
of cadmium (ii) from saturated kaolinite by the application of electrical current."
Geotechnique, 44 (2), 239-254.
[2] Lo, K. Y., Micic, S., Shang, J. Q., Lee, Y. N., and Lee, S. W. (2000).
"Electrokinetic strengthening of a soft marine sediment." International journal of
offshore and polar engineering, 10 (2).
[3] Micic, S., Shang, J. Q., and Lo, K. Y. (2002). "Electrokinetic strengthening of
marine clay adjacent to offshore foundations." International journal of offshore
and polar engineering, 12 (1).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
69
[4] Lo, K. Y., and Hinchberger, S. D. (2006) "Stability analysis accounting for
macroscopic and microscopic structures in clays." Fourth International
Conference on Soft Soil Engineering, Vancouver, Canada, 3-34.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
70
Nº REF.: O268
A continuous multi-scale model for ionic transport through electrically charged membranes
J.M. Paz-Garciaa, M. Villen-Guzman
b, M. Ristinmaa
a, J.M. Rodriguez-Maroto
b
a Division of soil mechanics, Lund University, Lund, 22363, Sweden
b Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain
Corresponding author: [email protected]
Electrically charged (ion-exchange) membranes (IEMs) are used in several technologies
for separation and energy production [1, 2]. In electrokinetic remediation (EKR), IEMs
are receiving considerable attention, as they produce selective separation with low
energy consumption. IEMs are the base for electrodialytic soil remediation processes
[3]. In this context, the membranes are used for the design of these enhanced
techniques; e.g. to control the pH of the media by hindering the acidic or alkaline fronts,
to create electrolyte compartments between the treated sample and the electrode
chambers for the selective recuperation of the contaminants, or to avoid contaminants to
reach the electrodes surface producing competitive electrochemical reactions.
Synthetic IEMs are normally organic polymers layers (homogenous films of 50-200 μm
thick) containing a certain amount of fixed (not mobile) of either positive or negative
charge (typically in a concentration of at least 3-4 mol g-1
). The fixed charge is
electrically counteracted by ions of the opposite sign (counterions). IEMs allow the
passage of the counterions but exclude ions with the same charge (coions). In IEMs, the
transport number, t, (defined as the fraction of the total current carried by a particular
ion) of the excluded ions is very small, t ~ 0.05, as the current is mainly transported by
the counterions. The sum of the transport number of the counterions is a measure of the
relative permeability or permselectivity of the membrane.
Figure 1. Depiction of the electric potential in the membrane and the adjoining electrolytes for the
two models compared: (a) discontinuous Donnan potential; (b) surface potential.
Traditionally, two different approaches are used for modelling the transport of ions
through electrically charged membranes: (1) the discontinuous Donnan model, and (2)
the continuous surface potential (or Gouy-Chapman double-layer potential) model [4,5].
, , exp ; 1,2,...,i m i i Dc c z i N (1)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
71
(2)
The Donnan model is based on the Donnan equilibrium equation, Eq. 1, for each of the
N species in the system, and the electroneutrality condition, Eq. 2, [5], where
(mol m-3
) is the concentration, the subscript m and refer to the membrane and the
bulk electrolyte respectively, (-), is the ionic charge, (-) is the dimensionless
potential drop between the membrane and the electrolyte, (C mol-1
) is the Faraday
constant, and (C m-3
) is the concentration of the membrane fixed charge (referred
to the volume of electrolyte assuming the membrane as a porous material).
The Donnan model is practical for cases in which the electrolytes are continuously
flowed, and the concentration can be considered constant in the perpendicular direction
of the membrane surface, therefore a value for the parameter is identified. In EKR
treatments, however, significant concentration gradients are formed in that direction
making the use of the Donnan model unfeasible or inaccurate.
The continuous surface model describes the interface between the membranes and the
electrolytes based on the Gouy-Chapman double layer model [6], which is:
(3)
(4)
Which is derived from the continuity equations, Eq. 3, coupled with the Poisson’s
equation of electrostatic, Eq. 4; where (mol m-2
s-1
) is the flux term (defined using
the Nernst-Planck equation, (mol m-3
s-1
) is chemical reaction term, (V) is the
electrical potential, and (C V-1
m-1
) is the permittivity of the media.
In the present work, we present a continuous multi-scale model for the transport of ions
through charged membranes. We consider a general multi-species and asymmetric
electrolyte case as an example of an electrodialytic remediation treatment, including
chemical reaction effects are included.
References
[1] R.F. Probstein, Physicochemical Hydrodynamics; an introduction. 2nd
ed. (1994),
John Wiley & Sons, Inc.
[2] A.H. Galama, J.W. Post, M.A. Cohen Stuart, and P.M. Biesheuvel, J. Memb. Sci.
442 (2013) 131.
[3] T.R. Sun, L.M. Ottosen, J. Mortensen, Chemosphere 90 (2013) 1520.
[4] V.M. Volgin, A.D. Davydov, J. Memb. Sci. 259 (2005) 110.
[5] F.G. Donnan, Z. Elektrochem. 17 (1911) 572.
[6] J.M. Paz-Garcia, B. Johannesson, L.M. Ottosen, A.N. Ribeiro, J.M. Rodriguez-
Maroto (Submitted)
, 0i i m
i
X F z c
ic
iz D
F
X
,ic
; 1,2,...,ii i
cG i N
t
J
2 0i i
i
F z c
iJ
iG
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
72
Acknowledgements
Authors acknowledge the financial support provided by the Spanish Ministry of
Innovation and the FEDER fund of the EU through the Research Project ERHMES,
CTM2010-16824 and the UE project Electroacross IRSES-GA-2010 269289.
Oral Session 3: Scaling up and field applications
Session Chair:
Lisbeth M. Ottosen
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
75
Nº REF.: O313
Pilot scale electrodialytic treatment of MSWI APC residue to decrease leaching of toxic metals and salts
Pernille Erland Jensena,*
, Gunvor Kirkelunda, Celia Dias-Ferreira
b, Lisbeth M.
Ottosena
aTechnial University of Denmark, 2800 Lyngby, Denmark.
bCERNAS, Escola Superior Agrária, 3040-316 COIMBRA, Portugal.
*Corresponding author: [email protected]
A major challenge of municipal solid waste incineration (MSWI) technology is the
residue generated during the burning, and especially the air pollution control (APC)
residue. In Denmark, incineration with energy recovery is the chosen strategy for
handling municipal solid waste except for a few fractions like glass, paper, cardboard,
metal and hazardous waste which is sorted out at the source. Around 100,000 ton of
APC residue is produced annually and exported as hazardous waste to Norway and
Germany. The hazard arises from high amounts of mobile toxic elements, salts as well
as trace quantities of very toxic organic compounds and the highly alkaline pH.
Electrodialysis of semidry APC residue has shown potential for reduction of leaching of
toxic elements and salts [1,2] to produce a material feasible for substitution of cement in
mortar [3]. During the electrodialytic process, elements of potential value are
concentrated in the concentrate stream which implies a reduction in the volume of
hazardous material and a potential for regeneration.
Figure 1 Experimental setup
APC residue suspension
Concentrate
Electrolyte
ED stack
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
76
In this work, results of 23 pilot-scale treatments in an electrodialytic stack setup (figure
1) are reported. The experimental span is described in table 1. In all the experiments L/S
10 was kept for the suspension (5.3 or8kg APC residue and 53 or 80 l water were
mixed), and the suspension continuously treatedfor up to 24 hours in an electrodialytic
stack. Experiments were made with APC residues from dry, semidry and wet fluegas
cleaning system, as well as carbonated and pre-washed semidry APC residue.Sampling
was made regularly (every or every secondhour) during treatment.Current density(0 –
11.3 mA/cm2), different batch samples and aeration were varied to reveal optimal
treatment conditions and stability of the process.
Table 1. List of experiments
APC residue No. experiments Investigated parameters
Dry 2 Current density
Semidry 15 Current density, batch influence,
aeration
Semidry- carbonated 2 Carbonation pretreatment
Semidry-washed 1 Washing pretreatment
Wet 3 Current density, batch influence
Significant reduction in leaching of the critical elements Pb, Zn and Cl was obtained.
Leaching reduction depended somewhat on current density and treatment time, as a high
current density and long residence time gave operational problems in the set-up. Type of
pretreatment and type of APC residue also influence the remediation potential.
References
[1] P.E. Jensen, C.M.D. Ferreira, H.K. Hansen, J.U. Rype, L.M. Ottosen, A.
Villumsen, Journal of Applied Electrochemistry 40 (2010) 1173.
[2] G.M. Kirkelund, P.E. Jensen, A. Villumsen, L.M. Ottosen, Journal of Applied
Electrochemistry 40 (2010) 1049.
[3] G.M. Kirkelund, M.R. Geiker, P.E. Jensen, Nordic Concrete Research, Submitted.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
77
Nº REF.: O325
Multivariate analysis of variable importance in the scaling up of electrodialytic remediation of heavy metals from harbour sediments
Kristine B. Pedersena,*
, Lisbeth M. Ottosenb, Pernille E. Jensen
b, Tore Lejon
a,
a Department of Chemistry, The Arctic University of Norway, 9019 Tromsø, Norway
b Arctic Engineering and Sustainable Solutions, Technical University of Denmark, 2800
Kgs Lyngby, Denmark
*Corresponding author: [email protected]
Large amounts of polluted sediments are annually dredged around the world in order to
meet the demands of harbour development and/or to meet governmental acts to improve
the aquatic environment of harbours. The most common way of dealing with dredged
contaminated sediments is disposal at licensed landfills (land/deep sea), and in some
cases solidification/stabilisation of the sediments, e.g. in new harbour constructions.
The focus on treatment possibilities of the dredged polluted sediments prior to potential
re-use has been limited. With the general focus of developing sustainable societies in
which the amount of waste is reduced considerably, a bigger emphasis on identifying
and developing methods for removing pollutants from dredged polluted sediments prior
to recycling these, e.g. in construction materials, may be expected in the future.
Electrodialytic remediation (EDR) provides a method that has been proven to
successfully remove heavy metals from polluted harbour sediments in laboratory scale –
removing up to 98% of the initial heavy metal concentration and meeting international
recommendations from OSPAR [1-7].
The focus of this study was to contribute in the further development of the EDR method
for future scaling up. Three different set-ups were tested – two on laboratory scale and
one on bench-scale. The EDR set-ups in laboratory scale were the traditional three
compartment cells and the newly developed two compartment cells. In the three
compartment cells ion exchange membranes separate the sediment in suspension in the
middle compartment from the electrodes and circulating electrolytes at the end
compartments to prevent the produced proton and hydroxyl ions produced at the
electrodes from entering the compartment with the suspension. Water splitting at the
anion exchange membrane ensures the acidification of the sediment [8]. In the two
compartment cells the anode is placed directly into the compartment with the sediment
in suspension and the separated cathode compartment is maintained to prevent hydroxyl
ions produced at the cathode from disturbing the remediation process in the
compartment with the sediment in suspension. The EDR set-up on bench scale was
based on separating the sediment suspension from the electrodes and circulating
electrolytes. The sediment suspension was continually circulated through a system of
consecutive compartments separated by anion and cation exchange membranes; the
electrodes were placed at each end of the stack.
The targeted heavy metals in the study were chromium, copper, nickel, lead and zinc,
since elevated concentrations of these heavy metals were found in the sediments. A
preliminary laboratory scale screening of the experimental variables showed a relative
variable importance in the order remediation time>current density>cell set-up>>stirring
rate>liquid-solid ratio>light. Based on these results a multivariate experimental design
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
78
was applied to determine the relative importance of the variables: remediation time,
current density, type of sediment and type of EDR equipment (2-compartment cell, 3-
compartment cell, stack). Two types of polluted harbour sediments were used – one
from Hammerfest harbour in the Arctic region of Norway and one from Sisimiut
harbour in Greenland. Measurements of the metals aluminium, barium, calcium, iron,
potassium, magnesium, manganese, sodium and vanadium were made as indications of
the changes EDR may have on the sediment matrix.
Multivariate analysis of the results revealed the variable importance in the experimental
space. This was done by performing projection to latent structures (PLS) in which
relations between two matrices; X consisting of the experimental variables and Y
consisting of the responses, i.e. the remediation levels of the targeted heavy metals and
metals naturally occurring in the sediments were determined. The PLS analysis
determines whether the variation in the experimental variables are related to the
variation in the remediation levels.
The PLS analysis showed that the relative importance of remediation time, current
density, EDR equipment and type of sediment were similar in magnitude hence having
a similar affect on the remediation process. The highest remediation levels were found
when using the two compartment cell set-up. The measurements of naturally occurring
metals in the sediments indicated that the 2-compartment cell induced the biggest
disturbance to the sediment matrix. Comparing the laboratory scale set-ups with the
bench scale set-up showed that more heavy metals per mass of sediment were removed
in the EDR cells, however the EDR stack can contain and remediate larger volumes of
sediment. The results can be used as basis for future optimisation of the scaling up of
the EDR method.
References
[1] G. Nystroem, L. Ottosen, A. Villumsen, Sep. Sci. Technol., 40 (2005) 2245-2264.
[2] G.M. Nystroem, L.M. Ottosen, A. Villumsen, Environ. Sci. Technol., 39 (2005)
2906-2911.
[3] G.M. Nystroem, A.J. Pedersen, L.M. Ottosen, A. Villumsen, Sci. Total Environ.,
357 (2006) 25-37.
[4] K.H. Gardner, G.M. Nystroem, D.A. Aulisio, Environ. Eng. Sci., 24 (2007) 424-
433.
[5] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, J. Hazard. Mater., 169 (2009) 685-
690.
[6] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, Chemosphere, 79 (2010) 997-1002.
[7] L.M. Ottosen, G.M. Nystrom, P.E. Jensen, A. Villumsen, J. Hazard. Mater., 140
(2007) 271-279.
[8] H.K. Hansen, L.M. Ottosen, B.K. Kliem, A. Villumsen, J. Chem. Technol.
Biotechnol., 70 (1997) 67-73.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
79
Nº REF.: O326
Design of a pilot electrokinetic remediation plant for marine sediments contaminated by heavy metals
(PROJECT LIFE12 ENV/IT/442 “SEKRET”)
Renato Iannellia,*
, Matteo Masia, Alessio Ceccarini
b, Raffaella Pomi
c, Alessandra
Polettinic, Angelo Marini
c, Aldo Muntoni
d, Giorgia De Gioannis
d, Maria Beatrice
Ostunia and Reinout Lageman
e
a University of Pisa, Department of Energy Engineering, Systems, Land and
Construction, Via Gabba 22, 56122 Pisa, Italy. b University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy
c “La Sapienza” University of Rome, Dept. of Civil and Environmental Engineering,
Roma, Italy d University of Cagliari, Department of Civil and Environmental Engineering and
Architecture, Cagliari, Italy e Lambda Consult, Schuylenburgh 3, 2631 CN Nootdorp, Netherlands
*Corresponding author: [email protected]
Dredged sediments are often severely contaminated by a variety of hazardous
pollutants, mostly heavy metals and hydrocarbons originated from different sources
such as ship transport, harbour activities, industry, agriculture, municipal sewage and
others [1]. Polluted sediments cannot be dumped offshore or reused, and the most
common options are landfilling or disposal in confined basins. Due to the large amounts
of contaminated material dredged worldwide, these choices generally exhibit high costs
and environmental impact; therefore, effective decontamination techniques are required.
For finely grained matrices, most of the traditional treatment technologies have proved
to be ineffective [2]. Unlike the majority of techniques, Electrokinetic remediation
(EKR) is effective for fine grained, low-permeability soils and sediments. This
technique employs a low-intensity electric field which induces the mobilization of
contaminants and water through the porous media toward the electrodes, due to three
main transport mechanisms [3-5]: electromigration, electroosmosis and electrophoresis.
The suitability of electrokinetic remediation for removing heavy metals from dredged
marine sediments is under investigation within the SEKRET Life+ project (“Sediment
ElectroKinetic Remediation Technology for heavy metal pollution removal”), by means
of a demonstrative 150 m3 treatment basin to be built in an area of the port of Livorno
(Italy). In the port of Livorno almost 100000 m3/year of sediments are dredged on a
regular basis. An environmental seabed assessment performed in 2005 detected the
presence of sediments polluted by significant concentrations of Cd, Cr, Cu, Ni, Pb and
Zn. In order to design the treatment plant, several calculations and estimations have
been carried out based on data from laboratory tests. The methods and the parameters
used for the design of the plant are discussed below.
The installation will consist of the following elements (Figure 1): i) an electric power
supply section, ii) a treatment basin, iii) semi-permeable electrolyte wells (slotted pipes)
placed in the contaminated medium and connected to an electrolyte management
system, iv) an electrolyte management system for the conditioning of the electrolytes, to
maintain the pH to a desired level, v) an electrolyte treatment system comprising ion
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
80
exchange and reverse osmosis filtration, vi) a gas treatment unit (scrubber system) for
the abatement of Cl2 gas emissions, vii) a monitoring and control system (PLC).
The design of the plant involved the evaluation of several operational parameters. The
most critical parameters for the electrokinetic process are: i) the speciation and mobility
of the contaminants, ii) pH of the sediment and of the electrolytes, iii) the cation and
anion exchange capacity, iv) the buffer capacity and v) the resistivity. These parameters
were obtained from laboratory tests and used to calculate the design parameters.
The size of the basin will be 6x18x1.3 m. The electrode will be placed along array
arrangements, with 6 electrodes each row. The distance between anodes and cathodes
will be about 1 m. The wells will be about 1.3 m deep and their diameter will be 9 cm.
The anode wells will be sealed and connected to a venting circuit that will collect the
gases produced during plant operation (e.g. chlorine) and treat them with a scrubber.
The electrical power will be applied to the electrode arrays via 8 power supplies (50kW
total power), delivering up to 30V. The applied current density will vary as a function of
the resistivity of the sediments, with a maximum design value of 5 A/m2 to prevent
electrolyte overheating. The number of electrodes will be 108 and each one will deliver
max. 14 A. The electrode material will be titanium with an iridium oxide coating. The
design electrolyte flow rate was estimated by imposing an optimal pH level inside the
wells. This allowed us to calculate the rate of reagent dosage needed to control the pH
to the desired level, and an electrolyte flow rate which minimizes the pH range between
the inflow and outflow from each row of electrodes. The treatment duration and metal
migration were determined by a simplified model (which neglects geochemical
reactions). According to these estimates, the remediation will be completed within 18
months of operation.
Figure 1. “SEKRET” electrokinetic treatment plant layout.
References
[1] Peng, J., et al., The remediation of heavy metals contaminated sediment. Journal
of Hazardous Materials, 2009. 161(2-3): p. 633-640.
[2] Mulligan, C.N., R.N. Yong, and B.F. Gibbs, Remediation technologies for metal-
contaminated soils and groundwater: an evaluation. Engineering Geology, 2001.
60(1–4): p. 193-207.
[3] Acar, Y.B. and A.N. Alshawabkeh, Principles of electrokinetic remediation.
1993. 27(13): p. 2638-2647.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
81
[4] Reddy, K.R. and C. Cameselle, Electrochemical remediation technologies for
polluted soils, sediments and groundwater. 2009: Wiley & Sons Ltd. 732-732 p.
[5] Lageman, R., Electroreclamation: application in the Netherlands. Environmental
Science and Technology, 1993. 27(13): p. 2648-2650.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
82
Nº REF.: O352
Application of solar cell in electrokinetic remediation of As-contaminated soil in pilot scale
Eun-Ki Jeona, So-Ri Ryu
a, Kitae Baek
a,b,*
aDepartment of Environmental Engineering, Chonbuk National University, 567 Baekje-
daero, Deokjin, Jeonju, Jeollabuk 561-756, Republic of Korea bDepartment of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea
* Corresponding author (K.Baek) : Tel.:+82-63-270-2437; Fax:+82-63-270-2449; E-
mail: [email protected]
Abstract
Electrokinetic remediation has been applied to remove a wide range of contaminants
including heavy-metals, organic pollutants, and radioactive materials from contaminated
soil, sediments and sludge. Contaminants in the soil are removed by the application of
an electric current across the contaminated soil [1, 2]. In general, the cost of electrical
energy increases the total remediation costs in the electrokinetic technique, which is
approximately 25% of total operation cost [1, 3]. Recently, solar cell has attracted for
electrokinetic remediation because it generates direct current (DC) [3, 4]. Direct current
generated by solar cell can be suitable for electrokinetic remediation for contaminated
soils [4].
In this study, we evaluated the feasibility of solar cell for pilot scale electrokinetic
remediation. Soil was sampled from a real contaminated site nearby refinery plant and
classified as a clay loam. Initial arsenic (As) level was higher than Korean regulation
concentration. Two different power sources, solar panel and normal power supply, were
applied for the comparison. The open circuit voltage of solar cell is 20V and two solar
cell panels were connected in series. We used oxalic acid as an electrolyte based on the
previous experimental results. Figure 1 shows the EKR system schematic diagram used
in this study.
Figure 2. EKR system schematic diagram
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
83
Acknowledgement
This research was supported by Korea Environment Industry & Technology Institute
(KEITI)
References
[1] A.N. Alshawabkeh, A.T. Yeung, M.R. Bricka, J. Environ. Eng.-ASCE 125 (1999)
27-35.
[2] D.H. Kim, J.M. Jung, S.U. Jo, W.S. Kim, K. Baek, Sep. Sci. Technol.47 (2012)
2235-2240.
[3] S. Yuan, Z. Zheng, J. Chen, X. Lu, J. Hazard. Mater. 162 (2009) 1583-1587
[4] Y.H. Kim, D.H. Kim, H.B. Jung, B.R. Hwang, S.H. Ko, K. Baek., Sep. Sci.
Technol. 47 (2012) 2230-2234
Oral Session 4: Other uses. Miscellaneous.
Session Chair:
Gordon C.C. Yang
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
87
Nº REF.: O401
A decontamination of the soil contaminated with cesium using electrokinetic-electrodialytic technology
Gye-Nam Kim*, Seung-Soo Kim, Jei-Kwon Moon
Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-gu, Daejeon,
305-353, Korea
1. Introduction
The radioactive soil at the KAERI radioactive waste storage facility has a slightly high
hydro-conductivity, and was mainly contaminated with 137
Cs 30-35 years ago. Recently,
a soil washing method was applied to remove 137
Cs from the radioactive soil, but it
appeared that the removal efficiency of 137
Cs was low, and a lot of waste solution was
generated. Meanwhile, an electrokinetic decontamination method provides a high
removal efficiency of 137
Cs and generates little waste effluent. Thus, it was suggested
that an electrokinetic decontamination method is a suitable technology in consideration
of the soil characteristics near South Korean nuclear facilities. The electrokinetic
process holds great promise for the decontamination of contaminated soil as it has a
high removal efficiency and is time-effective for a low permeability. The soil
contaminated with cesium was sampled at an area near a nuclear facility in Korea. The
electrokinetic decontamination equipment and electrokinetic-elctrodialytic
decontamination equipment were manufactured to decontaminate the contaminated soil.
The removal efficiency according to the lapsed time by the electrokinetic
decontamination equipment and the electrokinetic-elctrodialytic decontamination
equipment was investigated through several experiments. The difference between the
removal efficiency of the electrokinetic-elctrodialytic decontamination without anion
exchange membrane and that of with anion exchange membrane was investigated
through several experiments. In addition, the removal efficiency trend according to
different cesium radioactivity of soil was drawn out through several experiments.
2. Manufacturing of decontamination equipment
Electokinetic equipment decontamination was manufactured for the experiments. The
electrokinetic decontamination equipment consists of horizontal soil cells, two electrode
compartments (anode/cathode rooms), a reagent reservoir, an effluent reservoir, and a
power supply, and 480 g of contaminated soil was placed into a horizontal soil cell of
4.5x5.9x14.5 cm for Experiment 1. In Experiment 1, a paper filter was inserted between
the electrode compartment and the contaminated soil to protect against an influx of soil.
A pump supplies a reagent to the reagent reservoir at 0.5-1 ml/min, and the reagent
reservoir supplies a chemical solution to the anode room. The electric current between
electrodes is 0.6A, and the electric voltage between electrodes is 4.5-5.2 V. The
temperature in the cathode room was below 65 C. Experiments 1and 2 used a different
soil sample radioactivity, and the electrokintic decontamination period was 21 days
without exception.
In experiment 2, an anion exchange membrane was inserted between the anode room
and the contaminated soil to protect against an influx of cesium ions, and a paper filter
was inserted between the cathode room and the contaminated soil. 200g of
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
88
contaminated soil was placed into a horizontal soil cell, namely, the ratio of liquid (mg)/
soil (g) is 0.5. Experiments 3 and 4 used soil samples with a different radioactivity, and
the electrokintic decontamination period was 21 days without exception. Also, 200g of
contaminated soil was placed into a horizontal soil cell, namely, at a ratio of liquid
(mg)/soil (g) of 0.5. In Experiment 4, an anion exchange membrane was inserted
between the anode room and the contaminated soil to protect against an influx of
cesium ions, and a paper filter was inserted between the cathode room and the
contaminated soil. 200g of contaminated soil was placed into a horizontal soil cell,
namely, at a ratio of liquid (mg)/soil(g) of 0.5. Fig. 1 shows schematic diagram of the
electrokinetic-electrodialytic decontamination equipment.
Fig. 1. A schematic diagram of the electrokinetic-electrodialytic decontamination equipment
3. Electrokinetic-electrodialytic decontamination results
Cesium (137Cs+) in the contaminated soil in the electrokinetic-electrodialytic
decontamination equipment was removed by electro-osmosis, electro-migration, and a
hydraulic pressure flow. The experimental electrokinetic-electrodialytic conditions were
as follows. When the decontamination period of 0.3 days, 2 days, and 7 days elapsed,
137Cs+ in the soil was removed by about 10%, 37%, and 68%. However, the removal
efficiency of 137Cs+ was reduced after 7 days, because the 137Cs+ on the surface of
the soil particle had almost been removed for 7 days. However, the removal efficiency
of Experiment 3 was increased more than Experiments 1 and 2, because Experiment 3
used an impellor to increase the surface area of soil particles making contact with
electrolyte in the horizontal soil cell. In addition, when the decontamination period of
10 days, 14 days, and 21 days elapsed, the 137Cs+ in soil was removed by about 75%,
78%, and 81%. The removal efficiency of Experiment 3 was increased more than
Experiment 1 and 2 owing to the impellor.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
89
An anion exchange membrane was inserted between the anode room and the
contaminated soil to protect against an influx of cesium ions in the electrolyte
occupying an upper part of a horizontal soil cell. When the decontamination period of
0.3 days, 2 days, and 7 days elapsed, 137Cs+ in the soil was removed by about 12%,
38%, and 83%. However, the removal efficiency of 137Cs+ was reduced after 7 days,
because the 137Cs+ on the surface of the soil particles had almost been removed for 7
days. The removal efficiency of Experiment 4 was increased more than that of
Experiment 3 because Experiment 3 used the anion exchange membrane to prevent the
contamination of 137Cs+ in the anode room. When the decontamination period of 10
days, 14 days, and 21 days elapsed, the 137Cs+ in soil was removed by about 91%,
93%, and 97%. Meanwhile, the more the origin radioactivity of soil decreased, the more
the removal efficiency of 137Cs+ was reduced. Table 1 shows removal efficiency
according to the lapsed time by electrokinetic-electrodailtic decontamination with an
anion exchange membrane (Experiment 4).
Conclusively, the removal efficiency of 137Cs+ from soil by electrokinetic-
electrodialytic decontamination technology was higher than that of 137Cs+ from soil by
electrokinetic decontamination technology. In addition, the anion exchange membrane
in electrokinetic-electrodialytic decontamination increased the removal efficiency of
137Cs+ from soil owing to the interception of an infiltration of 137Cs+ in the anode
room.
Table 2. Removal efficiency according to the lapsed time by electrokinetic-electrodailtic decontamination with an anion exchange membrane(Experiment 4)
OriginRed. 0.3
(days)
2
(days)
7
(days)
10
(days)
14
(days)
21
(days)
Removal
Eff. 1
20.5
(Bq/g) 14.0% 40.7% 86.5% 92.3% 95.1% 98.2%0.37
Removal
Eff. 2
12.4
(Bq/g) 12.7% 38.1% 83.9% 91.1% 93.5% 97.2% 0.35
Removal
Eff. 3
5.8
(Bq/g) 11.9% 36.7% 81.4% 87.5% 91.3% 95.4% 0.27
Removal
Eff. 4
1.7
(Bq/g) 11.1% 35.3% 79.5% 85.3 % 89.2% 94.1% 0.1
4. Conclusions
The difference between the removal efficiency of the electrokinetic-elctrodialytic
decontamination without an anion exchange membrane and that with an anion exchange
membrane was investigated through several experiments. The removal efficiency of 137
Cs+ from soil by electrokinetic-electrodialytic decontamination technology was
higher than that of 137
Cs+ from soil by electrokinetic decontamination technology. In
addition, the anion exchange membrane in electrokinetic-electrodialytic
decontamination increased the removal efficiency of 137
Cs+ from soil
owing to the
interception of an infiltration of 137
Cs+ in the anode room. Meanwhile, the more the
origin radioactivity of soil decreased, the more the removal efficiency of 137
Cs+ reduced.
When the electrokinetic-electrodialytic decontamination period of 0.3 days, 2 days, and
7 days elapsed, 137
Cs+ in the soil was removed by about 12%, 38%, and 83%. However,
the removal efficiency of 137
Cs+ was reduced after 7 days because the
137Cs
+ on the
surface of soil particles had almost been removed for 7 days. When the decontamination
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
90
period of 10 days, 14 days, and 21 days elapsed, the 137
Cs+ in soil was removed by
about 91%, 93%, and 97%.
References
[1] G. N. Kim, W. K. Choi, C. H. Bung, J. K. Moon, J. Ind. Eng. Chem. 13 (2007)
406-413.
[2] G.N. Kim, Y.H. Jung, J.J. Lee, J.K. Moon, Journal of the Korean Radioactive
Waste Society. 25(2)(2008) 146-153.
[3] K. Reddy, C.Y. Xu, S. Chinthamreddy, J. Hazard. Mater. B84 (2001) 279-296.
[4] S. Pamukcu, J.K. Wittle, Environ. Prog. 11(3) (1992) 241-270.
[5] K. Reddy and S. Chinthamreddy, J. Geotech. Geoenviron. Eng., March. (2003)
263-277.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
91
Nº REF.: O439
Electrokinetic driven low-acid IOR in Abu Dhabi tight carbonate reservoirs
Arsalan Ansaria Mohamed Haroun
b,*, Mohammed Motiur Rahman
c, George V.
Chilingard
a, b, c The Petroleum Institute, Abu Dhabi, P.O. Box: 2533, U.A.E.
bUniversity of Southern California, Los Angeles, CA 90089, USA
*Mohamed Haroun: [email protected]
Abstract
Conventional acidizing, though useful in increasing the effective permeability in the
near well-bore region, has compatibility and operational issues such as limitation in
depth of penetration and HSE issues to handle, transport and injection ofhigh
concentration of acid into the well. On the other hand, the application of electrokinetics
(EK) has a number of economic and environmental advantages such as reduced oil
viscosity, reduced water-cut, and no depth limitation [1]. This study presents recent
research that demonstrates the impact of EK on matrix acid stimulation in Abu Dhabi
carbonate reservoirs with varying acid concentrations and voltage gradients [2].
Core-flood tests were conducted by saturating core-plugs retrieved from Abu Dhabi
oilfields with medium and light crude oil in a specially designed HTHP EEOR core-
flood setup[3]. Initially, EK was applied using acids of varying concentrations from
0.125 to 1.2% HCl injected at the anode to cathode (producer) at 0.25ml/min.
Experiments were also repeated with low concentration HClstimulation without the
application of EK.
Several correlations related to acid concentration, displacement efficiency and
permeability enhancement are presented here at ambient and reservoir conditions as
shown in Fig.1 and Fig.2. The experimental results have shown that upon the
application of waterflooding on the carbonate cores yields an average oil recovery of
60%. An additional 17-29% oil recovery was enhanced by the application of EK-
assisted low concentration HCl IOR (EK LA-IOR) at Abu Dhabi reservoir conditions.In
addition, EK LA-IOR was shown to enhance the reservoir’s permeability by
approximately 11-53% across the tested core-plugs.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
92
Fig. 1. Effect of EK LA IOR on permeability enhancement using 0.5, 1, and 2 V/cm.
Fig. 2. Effect of EK LA IOR on oil displacement efficiency using 0.5, 1, and 2 V/cm.
Fig. 3. EK LA IOR at elevated reservoir temperature and pressure(formation water composition
270k ppm TDS) 30% increased oil displacement and more than 50% reduced water injected.
It was observed that low acid concentration with application of low voltage EK,
recorded a maximum oil displacement of 89% at reservoir conditions as shown in Fig.
3. Furthermore, this technique can be engineered to be a sustainableprocessin the
presence of EKas the concentration and voltage gradient can be optimized to reduce the
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
93
amount of acid injected and power consumption by 20-41% further improving
economic feasibility.
References
[1] Amba, S.A., Chilingar, G.V. and Beeson, C.M., 1964. Use of direct electrical
current for increasing the flow rate of reservoir fluids during petroleum recovery.
J. Canad. Petrol. Technol., 3 (1):8-14.
[2] Ansari A., Haroun M., Rahman M., Chilingar G., Wittle J.K. “Electrokinetics
Assisted Acidizing for Enhancing Oil Recovery in Abu Dhabi Carbonate
Reservoirs”. Electrokinetic Remediation Conference, EREM 2013, June 23-26,
2013.
[3] Haroun M., Wittle J.K. and Chilingar G.V., 2012. Publication No.
WO/2012/074510. Title of the invention: "Method for Enhanced Oil recovery
from Carbonate Reservoirs." Applicants: ELECTRO-PETROLEUM, INC. (US).
Inventors: Mohammed Haroun (AE), J. Kenneth Wittle (US) and George
Chilingar (US), June 12.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
94
Nº REF.: O453
Selective recovery of dissolved metals from acid mine drainage via electrochemical method
S.M. Parka, S.W. Ji
b, K. Baek
a, c*
aDepartment of Environmental Engineering, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea bEnvironmental Hazardous Group, Korea Institute of Geoscience and Mineral
Resources, Daejeon 305-350, Republic of Korea cDepartment of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea
*Corresponding author: Tel.:+82-63-270-2437; Fax:+82-63-270-2449; E-mail:
In Korea, heavy metals contamination by abandoned mines has been a serious
environmental problem. Especially, acid mine drainage (AMD) contaminates the down-
stream of mines because that contains various toxic heavy metals as well as dissolved
iron and aluminum [1]. Recently, several researchers investigated to solve the
environmental problem related to AMD in points of recovery of metals instead of
removal in AMD. In the previous study, we reported that it is possible to recover
dissolved Fe, Al, Cu, and Zn/Ni from AMD by selective precipitation [2]. However, the
recovery consumed too much neutralizing chemicals such as neutralizing and oxidizing
agents. In this study, we produced oxidizing and neutralizing agent by electrochemical
reactions to reduce the usage of chemicals. The experimental conditions are shown in
the Table 1.
Table 1. Experimental conditions
Exp. Current (mA) Electrode Electrolyte
Membrane Anode Cathode Anolyte Catholyte
1 0 - -
200mg
Fe(II)/L
0.3M
NaHCO3
Nafion
N117
2 30 Graphite
Titanium
3 60 Titanium
4 60 BDD
5 60 Graphite
6 80 Graphite
7 Solar-cell Graphite
We hypothesized that ferrous was oxidized into ferric at the anode surface or in the
anolyte, and the cathodic reaction generated high concentration of hydroxide, a
neutralizing agent in the selective precipitation. We investigated the oxidation rate
constants, which were highly dependent on the anode materials (Fig.1(a)). Graphite
anode shows the highest oxidation rate, and the catholyte pH was independent on the
electrode material. Additionally, higher current enhanced the oxidation rate (Fig.2(b)).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
95
Based on the result, ferrous can be oxidized to ferric iron via directive oxidation on the
anode surface, and it is potentially possible to produce neutralizing agent and to be used
for selective recovery of dissolved metals from AMD.
Time (hr)
0 1 2 3 4 5
0mA (Graphite)
30mA (Graphite)
60mA (Graphite)
80mA (Graphite)
Time (hr)
0 1 2 3 4 5
Ferr
ou
s iro
n c
on
cen
trati
on
(m
g/L
)
0
50
100
150
200
60mA (Titanium)
60mA (BDD)
60mA (Graphite)
(b)(a)
Figure 1. Concentration of ferrous iron in anolyte, (a) electrode types, (b) currents
Acknowledgement
This work was supported by Korea Institute of Geoscience and Mineral Resources
(KIGAM).
References
[1] D. Mohan and S. Chander, Removal and recovery of metal ions from acid mine
drainage using lignite – A low cost sorbent, J. Hazard. Mater. 137 (2006) 1545-
1553.
[2] S.M. Park, J.C. Yoo, S.W. Ji, J.S. Yang, and K. Baek, Selective recovery of Cu,
Zn, and Ni from acid mine drainage, Envrion. Geochem. Health 35 (2013) 735-
734.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
96
Nº REF.: O464
Desalination of granite and sandstones by electrokinetic techniques. Comparison
Jorge Feijoo Condea*
, Ondrej Matyščákb, Lisbeth M. Ottosen
c, T. Rivas
aDept. of Natural resources and environmental. University of Vigo Campus Lagoas,
36310 Vigo-Spain bDepartment of Civil Engineering, Brno University of Technology, 602 00 Brno, Czech
Republic cDepartment of Civil Engineering, Technical University of Denmark, 2800 Kgs. Lyngby,
Denmark
Soluble salts are considered as a main reason for damage of porous building materials
such as rocks, bricks, granites which are used in the building constructions of the
architectural and archaeological heritage. Soluble salts are also responsible for various
forms of deterioration such as sand disaggregation and superficial detachments [1-3].
These problems can be solved by conservation technologies which are aimed at
decreasing the salt concentration in the rocks (desalination).
The present study aims to investigate the efficiency of electrokinetic techniques for
desalination of two different kinds of rocks such as granite and sandstone in which this
technique had already been shown to be effective [4, 5]. These rocks were contaminated
with NaCl solution and the thickness of the samples used in the tests was 6 cm. This
study compares the percentage removal of salts at different depths (efficacy) and the
time needed to get this percentage removal (effectiveness) achieved in both stones.
From the results obtained, it was possible to find those inherent factors to each stone
which could have an influence on the efficacy of the treatment.
As the results, this technique reduced the salt concentration in the granite almost to 100
%, however, in the sandstone samples the decreases were not so high mainly at the
intermediate levels (Figure 1) where slight enrichments were observed. The obtained
results indicate that although the used technique is efficient for the salt removal
regardless of porosimetric distribution of the rock, the better interconnection between
the pores (the granite used in this research had a better interconnection) favored that the
desalination process in the material happened faster.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
97
Figure 1.: a) chloride content (%Cl- g/g referred to the dry weight of the stone) by depth inside the
stones (granite; sandstone) before and after desalination test (seven application); b) efficacy (%Cl-) achieved in each rock
References
[1] Charola, A.E. Salts in the deterioration of porous materials: an overview. Journal
of America Institute of Conservation 39 (2000) 327-343.
[2] Doehne, E. Salt weathering: a selective review. Segesmund S., Weiss T. and
Vollbrecht A. Natural stone weathering phenomena, conservation strategies and
case studies. Geological Society. London. Special publications, 205, 51-64
(2002).
[3] Silva, B.; Rivas, T.; Prieto, B. (2003).- “Soluble salts in granitic monuments:
origin and decay effects. Applied Study of Cultural Heritage and Clays.J.L. Pérez
(Ed.), pp 113-130.
[4] Feijoo. J.; Nóvoa. X.R.; Rivas. T.; Mosquera. M.J.; Taboada. J.; Montojo. C.;
Carrera. F. (2012).- “Granite desalination using electromigration. Influence of
type of granite and saline contaminant”. Journal of Cultural Heritage.
[5] Ottosen, L.M.; Christensen, I. (2012) Electrokinetic desalination of sandstones for
NaCl removal – Test of different clay poultices at the electrodes. Electrochimica
Acta
Acknowledgements
J. Feijoo research was funded by a FPU-predoctoral grant by the Ministerio de
Educación of Spain.
Oral Session 5: Organic and chlorinated organic compounds remediation
Session Chair:
Claudio Cameselle-Fernández
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
101
Nº REF.: O520
Electrodialytic process applied for phosphorus recovery and organic contaminants remediation from sewage sludge
P. Guedes*, E. P. Mateus, N. Couto, C. Magro, A. Mosca, A. B. Ribeiro
CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências
e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
*Corresponding author: [email protected]
In Europe, contamination by organics and inorganics is a concerning problem. Waste
material streams such as sewage sludge contribute for it. However, this waste stream,
considered as deleterious material, can be a source of important secondary resources
that nowadays are lost. In fact, sewage sludge from waste water treatment plants may
contain contaminants or unwanted elements regarding specific applications, but it also
contains secondary resources of high value like phosphorus that is one of the essential
nutrients in nature. Phosphate rock, the world main source phosphorus, is a non-
renewable resource, and it is expected to last 100 years becoming important to find new
strategies for phosphorus recovery. The electrodialytic process can be an option to
recover phosphorus from sewage sludge.
The present work discusses the efficiency of the electrodialytic process applied to
sewage sludge aiming phosphorus recovery and organic contaminants removal. Eight
organic contaminants, that are known to be endocrine disruptors, were studied: caffeine
(CAF), 17β-oestradiol (E2), 17α-ethinyloestradiol (EE2), triclosan (TCS), bisphenol A
(BPA), nonylphenol (NP), octylphenol (OP) and Oxybenzone (MBPh) in sewage sludge
in a laboratory cell.
Sewage sludge samples were spiked with all studied contaminants subjected to a low
level direct current. The laboratory cell was divided in two compartments where the
electrodes were placed [1]. Experiments were carried out with and without pH control in
the electrolyte compartment.
Due to water electrolysis, hydroxyl radicals (•OH, oxidation potential of 2.8 V NHE-1
)
are continuously being generated and can oxidize organic contaminants unselectively at
a diffusion-controlled rate. For this, degradation of the organic contaminants due to
water electrolysis was also studied.
Results show that remediation of organic contaminants and simultaneous phosphorus
recovery seems to be feasible through an integrated approach with different
remediation/removal mechanisms (electrokinetic transport, electro- and photo-
degradation).
Acknowledgements
Financial support was provided by FP7-PEOPLE-2010-IRSES-269289-
ELECTROACROSS - Electrokinetics across disciplines and continents: an integrated
approach to finding new strategies for sustainable development,
PTDC/ECM/111860/2009 - Electrokinetic treatment of sewage sludge and membrane
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
102
concentrate: Phosphorus recovery and dewatering. N. Couto acknowledges Fundação
para a Ciência e a Tecnologia for Post-Doc fellowship (SFRH/BPD/81122/2011).
References
[1] Ottosen, L.M., Jensen, P.E., Kirkelund, G.M., Ebbers, B. (2014). Electrodialytic
recovery and purification of phosphorous from sewage sludge ash, sewage sludge
and wastewater. Filed in 2013, Denmark.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
103
Nº REF.: O523
Integration of electrokinetic process and nano-Fe3O4/S2O82- process for
remediation of phthalates in river sediment
Gordon C. C. Yang a, b, *
, Yu-Han Chiua, Chih-Lung Wanga
a Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung
80424, Taiwan b Center for Emerging Contaminants Research, National Sun Yat-Sen University,
Kaohsiung 80424, Taiwan
*Corresponding author: [email protected]
In this work the injection of nanoscale Fe3O4 slurry and sodium persulfate solution
coupled with electrokinetic (EK) process was tested for remediation of phthalate esters
(PAEs) in river sediment. The electrokinetic-assisted nano-Fe3O4/S2O82-
process has
been reported for remediation of soils contaminated by trichloroethylene and nitrate [1,
2]. The same process was employed in this work for remediation of river sediments
contaminated by di-n-butyl phthalate (DnBP; 1,909 μg/kg), di-(2-ethylhexyl) phthalate
(DEHP; 2,049 μg/kg), and di-iso-nonyl phthalate (DiNP; 929 μg/kg). First, nanoscale
Fe3O4 and its slurry were prepared in the laboratory. Then, several tests with different
reaction time (0-28 d) were carried out using the electrokinetic-assisted nano-
Fe3O4/S2O82-
process for PAEs degradation. In all EK tests, the anolyte and catholyte
were the river water obtained from the sampling site of river sediment of concern.
Nanoscale Fe3O4 slurry and sodium persulfate solution were injected into the same
electrode reservoir simultaneously or different electrode reservoirs separately on a daily
basis. Major research findings are given as follows: (1) under the optimal operating
conditions (i.e., titanium electrodes, electric potential gradient of 2 V/cm, reaction time
of 14 d, and daily injection of 3.14 g Na2S2O8 and 0.63 g nano-Fe3O4 into the anode
reservoir), overall removal efficiencies of 93.62%, 51.73%, and 98.92% were obtained
for DnBP, DEHP, and DiNP, respectively; (2) when nano-Fe3O4 slurry and Na2S2O8
solution were injected into the anode reservoir and cathode reservoir separately, a
serious electrochemical corrosion of titanium anode occurred because of the presence of
an electron acceptor (i.e., nano-Fe3O4) in the anode reservoir; (3) DEHP, reported by
others as a refractory organic contaminants, was the most persistent phthalate to degrade
in this work; and (4) more than 10 intermediate products due to PAEs degradation by
the nano-Fe3O4/S2O82-
process could be determined. In conclusion, the electrokinetic-
assisted nano-Fe3O4/S2O82-
process employed in this study is a viable technology for
river sediment contaminated by phthalate esters.
References
[1] G.C.C. Yang, C.F. Yeh, Sep. Purif. Technol. 79 (2011) 264.
[2] G.C.C. Yang, M.Y. Wu, Sep. Purif. Technol. 79 (2011) 272.
Oral Session 6: EKR in combination with other techniques
Session Chair:
Juan M. Paz García
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
107
Nº REF.: O604
Different strategies to enhance bioremediation of diesel-polluted soils using electro-kinetic processes
M.A. Rodrigo*, E. Mena, C. Ruiz, C. Saez, J. Villaseñor, P. Cañizares
Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies
& Institute of Chemical and Environmental Technology, Ciudad Real, 13071 SPAIN
*Corresponding author: [email protected]
In this lecture, different strategies for the remediation of spiked soils combining
biological processes with electro-kinetic soil flushing and permeable reactive barriers
are assessed at bench scale in clay and sandy soils using two-week long treatment tests.
Strategies applied are: 1) Direct combination of bioremediation with electrokinetic soil
flushing using bicarbonate solution as flushing fluid 2) single electro-bioremediation
processes with periodic polarity reversal 3) electrokinetic soil flushing with permeable
reactive bio-barriers using surfactant solutions as flushing fluids.
Results obtained depend strongly on the type of soil and, as expected, combinations are
only worth for clay soils. In this case, results show that efficiencies obtained with
classical bioremediation are not improved but worsen with the direct combination of
EKSF. These unexpected results are explained in terms of the difficult regulation of pH
and also because of the high temperatures reached under high electric fields (due to the
huge ohmic drops). Both parameters influence negatively on the viability of the
biological culture and finally cause its depletion. In this strategy, temperature also plays
a very important role on results because it favors volatilization of the pollutant.
On the contrary, efficiencies are greatly improved respect to single bioremediation using
permeable reactive bio-barriers consisting of either fixed cultures of acclimated
microorganisms or beds of soil mixed with suspended cultures. In this case, pH
regulation effect is not as dramatic as in the strategy 1 and microorganisms degrade very
efficiently the diesel pollutant.
Electro-bioremediation with periodic polarity reversal also shows good efficiencies
avoiding the problems caused by acidic and basic fronts on microorganisms, although
the rates obtained are far below those obtained by bio-barriers.
Changes in the concentration of nutrients, pH, conductivity and temperature are also
analyzed in this work giving light about the ways in which these processes can be
applied at the full scale in a synergistic way. Table 1 shows a summary of the main
results obtained in the three strategies discussed in this lecture
Table 1. Results of the different strategies after 14-days long remediation tests
Single
Bioremediation
Alternative 1
(single EBR)
Alternative 2
(reversal EBR)
Alternative 3
(EBR with PRB)
% COD Removed 11.79 11.36 18.12 26.78
Power Consumption (kW·h/TmSoil) -- 1238.5 145.3 90.3
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
108
At this point, matters related with scale up in soil remediation processes are discussed,
pointing out the difficulties of obtaining the same controlling mechanisms in setups at
different scales and hence the uncertainness of the reproducibility of results at different
scales [1,2].
Acknowledgements
Financial support from the Spanish government through project CTM2013-45612-R
and Innocampus (Procesos de electrorremediación, biorremediación y electro-
biorremediación de suelos contaminados) is gratefully acknowledged.
References
[1] E.Mena, J.Villasenor, P. Cañizares, M.A. Rodrigo, Journal of Environmental
Science and Health Part a 46 (2011), 914
[2] R. Lopez-Vizcaino, J. Alonso, P Cañizares, M.J. Leon, V. Navarro, M.A.
Rodrigo, C. Saez, Journal of Hazardous Materials 265 (2014) 142
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
109
Nº REF.: O606
Feasibility of coupling permeable bio-barriers and electrokinetic soil flushing for the treatment of organic chemical polluted soils
E. Menaa, C. Ruiz
a, C. Sáez
b, J. Villaseñor
a,*, M.A. Rodrigo
b, P. Cañizares
b
a Chemical Engineering Department. Research Institute for Chemical and
Environmental Technology (ITQUIMA). University of Castilla La Mancha, 13071,
Ciudad Real, Spain. b Chemical Engineering Department. Faculty of Chemical Sciences and Technology.
University of Castilla La Mancha, 13071, Ciudad Real, Spain.
*Corresponding author: [email protected]
This work presents the results obtained in the application of a novelty technique for the
treatment of polluted soils, which combines two previously well known technologies:
(1) Electrokinetic soil flusing (EKSF), consisting on applying an electric field to the
polluted soil for the drag of species through different mass transport processes [1, 2],
and (2) Biological permeable reactive barriers (Bio-PRB), which are based on
mobilizing the polluted groundwater through a barrier on which a supported microbial
consortia degrades the pollutants [3, 4]. Two experiments have been performed using
organic chemical-polluted clay soils in order to study the feasibility of the proposed
combined technology. We used two well-differenced organic compounds: the first one
was glucose, which is a highly biodegradable organic substrate and it was used with the
purpose of checking the viability of the treatment proposed; the second one was diesel,
which is a pollutant itself and its occurrence in the environment is unfortunately very
widespread. The bench-scale setup used in the tests in this work is schematized in the
Figure 1.
Figure 1: Bench-scale setup.
The setup was made in transparent methacrylate. The Bio-PRB with the attached
microbial consortia was located in the central part of the polluted soil section. As long
as the soil treatment was performed, the biological barrier was flooded in an inorganic
nutrients solution. Synthetic low permeability soil was used in all the experiments
(kaolinite). All the experiments were performed in a potentiostatic way, setting a
constant voltage gradient (1 V cm-1
). Different parameters directly related with the
biological degradation process were daily monitored during the experiments (e.g.
Cathodic Compartment
Power Supply
Graphite electrode CathodeGraphite electrode Anode
VA
Anodic Compartment
Collector Compartment
Collector Compartment
20 cm.
10cm
.
Polluted Soil BB Polluted Soil
Level
Control
Electrolite:
Syntethic
tap water
E.O.
volume
Multimeter
mA
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
110
electrical current, temperature, pH and inorganic nutrient concentrations). At the end of
the experiments, an in-depth sectioned analysis of the complete soil section was done.
Figure 2. a) Glucose test conditions in the Bio-PRB medium: temperature (), dissolved oxygen
(), pH (); b) Diesel test conditions in the Bio-PRB medium: temperature (), dissolved oxygen (), pH (). c) Relation between pH and microbial population in the soil at the end of the tests: pH () and microbial concentration () in the glucose-test; pH () and microbial
concentration () in de diesel-test. d) Pollutants removal: diesel and glucose concentration at the beginning of the tests (), diesel concentration at the end of the test (), glucose concentration
at the end of the test ().
Temperature, dissolved oxygen and pH were between optimal values for the biological
degradation process during all the experiments (Figure 2.a and b), which confirmed that
the position of the barrier in the middle point of the soil section was adequate for the
proposed technology. As it was expected, values of pH obtained in the nearness of the
anode were acid, and, in the same way, values obtained in the nearness of the cathode
were basic (Figure 2.c). Because these pH conditions, activity of the microorganisms in
these areas was inhibited. Microbial concentrations were higher in the central areas
where the pH values were around the neutral value. Regarding the organics removal,
glucose was completely removed from the soil because its high water solubility and
biodegradability (Figure 2.d). On the other hand, a diesel oil removal efficiency near to
the 27% was obtained.
From the results presented in this work it can be concluded that the combination of
EKSF with Bio-PRB technologies could be an efficient alternative for the removal of
organic pollution from low permeability soils. Most of the important parameters
influencing on the biodegradation process were successfully controlled and the
biological removal of pollutant was possible, with different efficiencies depending on
their biodegradability and solubility.
Acknowledgments
The financial support of the Spanish Government through projects CTM2010-18833
and CTM2013-45612-R and INNOCAMPUS is gratefully acknowledged.
0
5
10
15
20
25
0
1
2
3
4
5
6
7
8
9
10
0 50 100 150 200 250 300 350
Tem
per
atu
re (
ºC)
D.O
. (p
pm
) //
pH
Time (h)
0
5
10
15
20
25
0
1
2
3
4
5
6
7
8
9
10
0 50 100 150 200 250 300 350
Tem
per
atu
re (
ºC)
D.O
. (p
pm
) //
pH
Time (h)
a
b
1
10
100
1000
10000
100000
0
1
2
3
4
5
6
7
8
9
10
1 2 3 4
CF
U/g
So
il
pH
Position
0
2000
4000
6000
8000
10000
12000
1 2 3 4m
g(G
luco
se/D
iese
l)/k
gS
oil
Position
Anode CathodeBio-PRB
c
d
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
111
References
[1] R. López-Vizcaíno, C. Sáez, E. Mena, J. Villaseñor, P. Cañizares, M.A. Rodrigo,
J. Environ. Sci. Heal. A. 46 (2011) 1549
[2] R. López-Vizcaíno, C. Sáez, P. Cañizares, V. Navarro, M.A. Rodrigo, Sep. Sci.
Technol. 46 (2011) 2148
[3] S. Saponaro, A. Careghini, L. Romele, E. Sezenna, A. Franzetti, I. Gandolfi, M.
Daghio, G. Bestetti, WIT Trans. Ecol. Envir. 164 (2012) 439
[4] S. Saponaro, M. Negri, E. Sezenna, L. Bonomo, C. Sorlini, J. Hazard. Mater. 167
(2009) 545
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
112
Nº REF.: O608
Effect of electrokinetic enhancement on phytoremediation of soils with mixed contaminants
Reshma A. Chirakkaraa, Claudio Cameselle
b,*, Krishna R. Reddy
c
a Graduate Research Assistant, Department of Civil and Materials Engineering,
University of Illinois at Chicago, Chicago, Illinois 60607, USA b Associate Professor, Chemical Engineering Dept., University of Vigo, Vigo, Spain
c Professor, Department of Civil and Materials Engineering, University of Illinois at
Chicago, Chicago, Illinois 60607, USA
*Corresponding author: [email protected]
Soils contaminated with mixed contaminants are a major environmental problem
worldwide not only for their negatives effects for living organisms but also for the
complexity of their remediation. Many of the contaminated sites contain both organic
and inorganic (e.g. heavy metals) contaminants and their remediation is even more
complex due to the very different physic-chemical properties of both kinds of
contaminants. There are very few methods that can remediate both heavy metals and
organic contaminants in soils. Most of these methods, however, are energy intensive,
time consuming and expensive; and the remediation results largely depend on site
characteristics. In this context, phytoremediation is proposed as a promising method for
remediation of sites with contamination mixtures.
Phytoremediation is a green and sustainable remedial strategy, most appropriate for
large sites with low contamination levels [1]. This technology is based on the growing
of selected plants in the contaminated site to extract, stabilize or degrade the
contaminants in the soil around the plant roots [2]. Several mechanisms
(phytoextraction, rhizofiltration, phytostimulation and phytodegradation) have been
identified for the removal/degradation of contaminants in soil remediation due to the
plant activity. One of the major limiting factors in phytoremediation is the low
bioavailability of contaminants in the soil pore fluid. This limitation can be overcome
by the application of a low electric potential in the vicinity of the growing plant to
mobilize the contaminants in the soil [3]. Very few studies combining electrokinetics
and phytoremediation have been published [3], and they were all done on soils
contaminated only with heavy metals. The potential of the combined phytoremediation-
electrokinetics technology for mixed contaminated soils have not been explored.
This study aims in enhancing the bioavailability of contaminants for phytoremediation
by the application of a low voltage electric potential to the soil. Alternating current was
applied instead of DC, since the main objective is to increase the mobility and
bioavailability of the contaminants, but not their transport in a specific direction. Based
on their capability to survive and remediate in mixed contaminated soils, Avena sativa
(oat plant) and Helianthus annuus (sunflower) were selected for the study [4]. Mixed
contaminated soil was prepared by spiking silty clay soil, typical of the Chicago area,
with naphthalene, phenanthrene, lead, cadmium and chromium. Contaminated soil was
mixed with 200 g/kg of compost to improve plant growth [5]. The contaminated soil
was filled in five electrokinetic cells. Two cells were seeded with twenty seeds of Avena
sativa and two cells were seeded with twenty seeds of Helianthus annuus. One cell was
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
113
kept unseeded to study the effect of electric potential application without plant growth.
The cells were placed under metal halide grow lights of average photosynthetic photon
density of 400 µmols/m2 s. Grow lights were timed for 16 hours of light period per day.
After 30 days of plant growth, 25 V (alternate electric current) was applied 3h/day to
one cell with Avena sativa, one cell with Helianthus annuus and to the unplanted cell.
The plants were harvested after 61 days of seeding. The root and shoot biomass were
dried separately at 60°C for 6 days. Heavy metal content was determined in soil samples
by acid digestion (EPA method 3050B) followed by Flame Atomic Absorption
Spectroscopy (FLAA). The exchangeable fraction of metals in soil was determined by
extraction with sodium acetate followed by FLAA [2]. PAH analysis was done
following EPA method SW8270C with gas chromatography, after solvent extraction.
The experimental results revealed that Avena sativa had higher germination rate
compared to Helianthus annuus, which can be interpreted as an effect of the
contaminants in soil. The electric field did not seem to affect germination and survival
rates of the plants or the final maximum plant heights of both plants. However, total
biomass of both plants was found to be higher for plants in cells with electric potential
application. Avena sativa did not show any significant reduction (p>0.05) in Pb or Cd,
but in cells with Helianthus annuus, there was an approximate reduction of 23% Pb and
17% Cd. Exchangeable Pb was found to be zero in all cells whereas planted pots did not
show any significant difference in exchangeable Cd content compared to control.
Unplanted cell with electric potential application had higher exchangeable Cd compared
to control. Chromium concentration in soil was reduced significantly in all planted pots.
Approximate Cr reduction was 23% by Avena sativa and 18% by Helianthus annuus.
All the cells had lesser exchangeable Cr concentrations compared to the control. All the
planted cells had significantly lesser exchangeable Cr concentrations compared to the
cells with electric potential application only.
Naphthalene concentration was found to be zero in all the samples suggesting microbial
degradation and volatilization. There was no considerable difference in phenanthrene
concentration of different cells. This shows that the applied voltage and duration of the
electric potential may not be sufficient to increase the availability of contaminants for
plant uptake or plant promoted degradation. It is suggested to increase the application
time of the electric potential and the frequency of its application in order to enhance the
effect of the electric current on the bioavailability of contaminants.
References
[1] K. R. Reddy & R. A. Chirakkara, Geotech. Geol. Eng. 31 (2013) 1653.
[2] H. D. Sharma, K. R. Reddy, Geoenvironmental engineering: site remediation,
waste containment, and emerging waste management technologies. John Wiley &
Sons, New York. (2004).
[3] C. Cameselle, R. A. Chirakkara, K. R. Reddy, Chemosphere 93(2013) 626.
[4] R. A. Chirakkara, K. R. Reddy, Proc. 106th
Annual Conference & Exhibition, Air
& Waste Management Association, Pittsburgh, PA, (2013) 1.
[5] N. Karami, R. Clemente, E. Moreno-Jiménez, N.W. Lepp, L. Beesley, J. Hazard.
Mater. 191 (2011) 41.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
114
Nº REF.: O634
Potential of electrokinetic process to recover phosphorus and remove cyanotoxins from membrane concentrate
Nazaré Coutoa,*
, Paula Guedesa, Eduardo P. Mateus
a, Cristele Santos
b, Margarida
R. Teixeirab, Alexandra Ribeiro
a
a CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de
Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. b
CENSE, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de
Gambelas, 8005-139 Faro, Portugal.
*Corresponding author: [email protected]
Water treatment technologies, like membranes, can be used to guarantee safe levels of
contaminants in water. Nanofiltration (NF) is a viable option for drinking water
treatment that effectively removes cyanobacteria and cyanotoxins from algal blooms, a
phenomenon found worldwide in water reservoirs. The use of NF produces a clean
stream (permeate) but also a concentrate stream (membrane concentrate) that contains
all the compounds removed by the membrane. The presence of phosphorus (P) in
membrane concentrate suggests the possibility of nutrient recover for further re-use.
In this study NF was applied to produce membrane concentrates using water from two
portuguese Dam reservoirs as feed water. The purpose was to combine NF to
concentrate P existent in the concentrate stream followed by its recovering using the
electrodialytic process (ED). Contaminants from the concentrate stream were also
removed by ED. This is the case of microcystins (toxins produced by Microcystis
aeruginosa MC-LR), a high molecular weight compound, slightly negative and
hydrophilic that may cause severe health due to their acute and sublethal toxicity.
Applying a low level direct current the electrokinetic movement of ions is combined
with electrodialysis, promoting analytes movement towards one of the electrode
compartments, where they are concentrated and may be removed.
Electrodialytic process seems to be a feasible option for P recovery but its recovery
percentage depends on the characteristics of the waste streams. Complementary
experiments were also conducted to evaluate microcystins removal, MC-LR variant,
effectively purifying P from other contaminants.
Acknowledgements
Financial support for the work is provided by projects FP7-PEOPLE-2010-IRSES-
269289* ELECTROACROSS - Electrokinetics across disciplines and continents: an
integrated approach to finding new strategies for sustainable development and
PTDC/ECM/111860/2009 - Electrokinetic treatment of sewage sludge and membrane
concentrate: Phosphorus recovery and dewatering. N. Couto acknowledges Fundação
para a Ciência e a Tecnologia for her Post-Doc fellowship (SFRH/BPD/81122/2011).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
115
Nº REF.: O659
Electrodialytic removal of heavy metals from fly ash from co-combustion of wood and straw – influence from prewash
Wan Chen*, Lisbeth M. Ottosen, Pernille E. Jensen, Gunvor M. Kirkelund, Jacob
W. Schmidt
Department of Civil Engineering, Technical University of Denmark, Brovej, Building
118, DK-2800 Lyngby, Denmark
*Corresponding author: [email protected]
The heavy metal content in the fly ash from biomass combustion, such as straw, wood
and sludge, often needs to be lowered before the ash can be used as fertilizer at
agricultural land or in construction materials. In this study, fly ash from a boiler fueled
with wood chips and straw was either treated directly by electrodialytic remediation
(EDR) or a combination of prewash in water and EDR to lower the heavy metal content
(Figure 1). Different experimental set-ups (Figure 2 under different experimental
conditions in Table 1) were tested for treatment of the ash suspended in distilled water
in order to investigate the heavy metal removal. The investigation focuses on Cd and Pb
removal as these are the major problems in relation to the limiting values, but also other
heavy metals are reported: As, Cr, Cu, Ni and Zn.
Prewashing caused an increase in total concentrations of most heavy metals compared
to the ash before wash. This is because the high soluble fraction (around 80 %) is
removed and thus the heavy metals are concentrated in the ash as these are generally
little soluble in water.
After prewash, the limiting concentration of Pb (120 mg/kg) was exceeded. The
concentration in the washed ash was not lowered sufficiently during EDR in a 3
compartment cell (Figure 2-a), but after treatment in the EDR cell with 2 compartments
(Figure 2-b) the concentration met the requirement. The two compartment cell was
probably better (Table 2) due to the fast acidification process. However, this fast
acidification may in turn affect the leaching property of the treated ash, which has As,
Se and Ni exceeding the limiting concentrations. Ni needs attention in the ashes treated
in 3-compartment cell. The Cd concentration was reduced to below 2 mg/kg, no matter
how high the concentration was before the treatment.
Figure 1. Experimental design.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
116
Figure 2. The schematic drawing of the types of EDR cells used in the experiments: (a) 3-
compartment, and (b) 2-compartment. (AN: anion exchange membrane; CAT: cation exchange membrane).
Table 1. The experimental conditions.
No. Sample Current
(mA)
EDR cell
(compartment no.)
L/S
(L/kg)
Duration
(days)
Charge
(Coulombs)
E1 EFA-1 50 3 7 14 60480
E2 WEFA-1 50 (Day 1)1 to 10 3 7 ~ 67 60480
E3 WEFA-2 10 3 7 70 60480
E4 EFA-2 50 3 7 10 43200
E5 WEFA-2 40 3 7 10 34560
E6 WEFA-2 40 2 7 10 34560 1The voltage between the two working electrodes went up to the maximum voltage of the power
supply on Day 1, so the current was changed to 10 mA from Day 2.
Table 2. Cd and Pb removal from the EDR experiments.
E1 E2 E3 E4 E5 E6
Cd Removal
efficiency1,%
98
96
96
98
94
98
Mass
balance2, %
91
102
100
106
105
93
Pb
Removal
efficiency,%
Mass
balance, %
67
94
18
96
25
91
48
122
12
94
47
83 1The removal efficiency was calculated from the mass difference of the element in the ash
before and after treatment divided by the initial mass in the ash.
2Mass balance was defined as the percentage of the total final mass of the element, found in all
parts of the cell (electrodes, electrolyte, membranes, ash suspension), in its initial mass input
from the ash.
Poster Session: Metal Removal and transport of inorganics
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
119
Nº REF.: P110
Remediation of cuprum from clay soils
Romanova I.V.a, Korolev V.A.
b
aStudent of Geological Faculty of MSU named M.V. Lomonosov, Moscow, 119991,
Russia; e-mail address: [email protected] b Professor of Geological Faculty of MSU named M.V. Lomonosov, Moscow, 119991,
Russia; e-mail address: [email protected]
The cleaning of clay soils from various heavy metals (HM) is the important issue, and it
is the great ecological value. Among the heavy metals cuprum is one of the major sites
as a contaminant of soil and other environmental components. Now, the electrokinetic
method is one of the effective methods of cleaning soil from cuprum. The complex
electrochemical and electro kinetic processes occurring in soils in the field of direct
electric current is at its core.
The study of electrosurface and electrokinetic soil processes conducted at the
Department of Engineering and Ecological Geology, Geological Faculty of Moscow
State University(MSU)since the 1960's, and their using for cleaning soils from various
toxic components(heavy metals, hydrocarbons, radionuclides, organic toxicants etc.) is
studied since 1995 [2].
Many patterns of electrochemical migration of heavy metals (including cuprum) are still
unexplained, despite a lot of work carried out in this area [1-4].Therefore, in this paper
we present the results of studies of this process and analyzes of the main factors
affecting on the remediation of cuprum from clay soils.
The laboratory investigation was performed in the electroosmotic cells of two types:
type one (type 1) envisaged a staic version of the experiment, and type two (type 2)
envisaged a flowing version simulating sample washing and electrochemical leaching
out the pollutant.
Cuprum as the toxicant, belong to the second class of hazard substances. Therefore, the
study of factors affecting on its electrochemical remediation is important for the
environment. The analysis of the main factors is described below.
1. The influence of mineral composition was studied on the non-flowing mode (type
1). It manifests itself through the features of the double electric layer (DEL) parameters,
which is formed around the particles of different mineral composition and in the pore
volume occupied by the DEL in the soil. This makes the different physico- chemical
and electrochemical activity clay soils. We studied monomineral clay (smectite, illite
and kaolinite) as well aspolymineral glacial clay soils. It was found that the
electrochemical activity of the clay soil decreases in the series: “smectite clays> illite
clays> kaolinite clays = polymineral clays”.
2. The influence of granulometric composition. The effect of granulometric
composition of soil on remediation of cuprum from clay soils was studied in call of type
1.The clay soil, which dispersion increased from sandy loam to light and medium loam,
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
120
was investigated. It was found that with increasing of dispersion the degree of cleaning
clay soils in the anode zone increases.
3. The influence of initial moisture. Experiments were performed on kaolinite clay at
the same initial concentration of cuprum in the samples- 12g /kg(i.e., related to a very
high degree of contamination).It has been found that in non-flowing variant (type
1),with increasing initial moisture the degree of cleaning soil from the cuprum in the
anode zone increases. This is due to the fact that magnitude of electroosmotic transport
increasing with the moisture increases because the thickness of the double electrical
layer (DEL) around the particles also increases.
4. The influence of the test. We have studied the cuprum removal efficiency by
comparing the results cleaning the same soil in the flowing and non-flowing cells.
Experiments have shown that the degree of purification of the soil in the anode area in
the flow variant (type 2) is greater than in non-flowing variant (type1). Electrochemical
leaching is more effective for cleaning. At the same time, the longer the flushing
process, the more copper is removed from the clay soil.
5. The influence of anolyte. Purpose fully selecting the composition of the anolyte, we
can increase the degree of purification of soil cuprum. The composition of the anolyte
may affect on the acidity of the pore solution environment (pH), as well as desorption of
cuprum from the cation exchange complex of the clay soil. In this way the
electrochemical mobility of cuprum may increase. Therefore, the degree of soil
decontamination increases in the mode of electrochemical leaching (type 2).
Experiments have shown that this can be used for the acidification of the aqueous
solutions.
6. The influence of cuprum forms in the soil. The cuprum, like many other heavy
metals in the soil is located in the different forms and ionic complexes. Each of them is
different will be exposed to an electric field and will exhibit different electrochemical
activity. There are different adsorption sites of cuprum in the clay soils; they have
different effects on the electrochemical mobility of cuprum. Usually to the determine
modes of occurrence of heavy metals use the method of successive extracts, for example
by the method of Tessier [1]. We confirmed that the greatest contribution to the removal
of cuprum from the clay soils makes cuprum, located in the soil cation exchange
complex, i.e.within the DEL. Consequently, all factors affecting on the characteristics of
DEL in the clay soil, will have impact on the electrochemical removal of cuprum from
them. Further, a smaller contribution to the removal of cuprum contributes the cuprum
adsorbed onto carbonates and oxides of Fe and Mn, an even smaller contribution is the
cuprum sorbed on organic substances. I.e. the cuprum humates most difficult to remove
from the soils. This is explained by the special forms of physical and chemical
interactions of cuprum with humic substances, including - with fulvic acids. Therefore,
the grounds containing humus, including soils and peats, it will be harder to clean from
cuprum than not humus soils.
7. The influence of impurities other HM. Also, the presence of other heavy metal
ions, such as ions Cd, Zn, Hg, Ni, Mo, etc. influenced on the electrochemical migration
of cuprum in the clay soils. And there are conflicting information in the press on this
factor [1].In our opinion these differences are explained by the different composition of
cations in the clay soil exchange complex, and consequently –by the different mutual
influence on the processes of adsorption and desorption.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Conclusion. Thus, the results of research showed that the electrochemical remediation
of cuprum from clay soils is the quite effective method for the purify of clay soils from
cuprum to the required environmental levels.
References
[1] V.A. Korolev, E.N. Samarin, Y.V. Shumkina, Engineering Research, 12 (2012)
72-78 (in Russian)
[2] V.A. Korolev. Cleaning of soils from pollutions. Moscow, MAIK
Nauka/Interperiodika, 2001, 365 p. (in Russian)
[3] L.M. Ottosen, I.V. Christensen, I.Rӧring-Dalgard, P.E. Jensen, J. of Environ. Sci.
and Heath, Part A. Toxic/Hazardous Substances & Environ. Engineering. 43(8)
(2008), 795-809
[4] A. Ribero, J.T. Mexia, J. Hazard. Mater. 56 (3) (1998) 257-277
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº REF.: P112
Testing of new shifting current electrodialytic treatment setup for efficient treatment of Cr-contaminated soil fines
Pernille Erland Jensena,*
, Lisbeth M. Ottosena, Gunvor Kirkelund
a
a Technial University of Denmark, 2800 Lyngby, Denmark.
*Corresponding author: [email protected]
Cr contamination is regularly encountered in surface soil and poses a risk towards
human health and the environment. Cr is particularly mobile and toxic in its oxidized
form: Cr(VI). Previous investigations of the influence of Cr-speciation on electrokinetic
remediation (EKR) in stationary setups showed that removal of Cr(III) occurred only
under highly acidic conditions [1], and Cr (III) removal from industrially contaminated
soils is slow compared to removal of other heavy metals [2]. It was shown that Cr(VI) is
much faster remediated by EKR than Cr(III) [3]. Indeed, Cr(VI) was observed to be
faster remediated than both Cd and and Ni under acidic conditions [1] and removal of
Cr(VI) was observed to increase at neutral/alkaline conditions from spiked soil [1].
Reduction of Cr(VI) to Cr(III) during stationary EKR was documented [1]. In general,
however, Cr was recovered in the anolyte when soils were spiked with Cr(VI) [1, 4, 5,
6] and in the catholyte when soils were spiked with Cr(III) [7, 8, 9]. When treating soil-
fines in a suspended setup as reported in [10], as much as 53% Cr was, however,
transferred to the catholyte as Cr(III) from a CCA-impregnation contaminated soil
within 10 days. But Cr(III) remained the slowest contaminant to remove compared to
both As, Cd, Cu, Ni, Pb and Zn; and from two other soils less than 20% Cr was
removed by identical treatment [10]. Thus development proper enhancement method is
needed to be able to remediate Cr(III)-contaminated soil efficiently.
In the present work, a new treatment concept is tested for its feasibility on Cr-
remediation. In the new setup, soil fines are treated in suspension with alternating
current between two anodes at different frequencies. One anode is placed in the anode-
compartment and the other anode is placed directly into the middle compartment
containing the soil fines suspension (figure 1) with the aim to oxidize Cr(III) to Cr(VI)
by direct contact between electrode and contaminant.
Figure 1. Experimental setup
+
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123
All experiments were made with soil from the Collstrop-site in Hillerød, Denmark,
contaminated by CCA-impregnation activity. Thus contaminated by Cu, Cr and As.
Experiments were made according to the plan listed in table 1.
Table 1. List of experiments
Exp. No of compartments (fig. 1) Frequency of alternating current
2C 2 (only II and III) 0 (i.e. only anode in middle compartment on)
3C 3 0 (i.e. only anode in anode compartment on)
3C-min 3 Every minute
3C-hour 3 Every hour
3C-day 3 Every 24 hours
The results show that direct contact between the contaminated soil fines and the anode
significantly enhances remediation efficiency of Cr.
References
[1] K.R. Reddy, S. Chinthamreddy, Journal of Geotechnical and Geoenvironmental
Engineering 129 (2003) 263.
[2] H.K. Hansen, L.M. Ottosen, B.K. Kliem, A. Villumsen, Journal of Chemical
Technology and Biotechnology 70 (1997) 67.
[3] S. Li, T. Li, F. Li, L. Liang, G. Li; S. Guo, Proceedings of 5th International
Conference on Bioinformatics and Biomedical Engineering (2011).
[4] K.R. Reddy, U.S. Parupudi, S.N. Devulapalli, C.Y. Xu, Journal of Hazardous
Materials 55 (1997) 135.
[5] K. Sanjay, A. Arora, R. Shekhar, R.P. Das, Colloids and Surfaces A -
Physicochemical and Engineering Aspects 222 (2003) 253.
[6] A. Sawada, S. Tanaka, M. Fukushima, K. Tatsumi, Journal of Hazardous
Materials 96 (2003) 145.
[7] Z.M. Li, J.W. Yu, I. Neretnieks, Journal of Hazardous Materials 55 (1997) 295.
[8] Z.M. Li, J.W. Yu, I. Neretnieks, Journal of Environmental Science and Health
Part A-Toxic/Hazardous Substances & Environmental Engineering 32 (1997)
1293.
[9] C.H. Weng, C. Yuan, Environmental Geochemistry and Health 23 (2001) 281.
[10] P.E. Jensen, L.M. Ottosen, B. Allard, Electrochimica Acta 86 (2012) 115.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
124
Nº REF.: P116
Electrokinetic remediation with novel electrode configuration
Ikrema Hassana, Eltayeb Mohamedelhassan
b*, Ernest K. Yanful
a
a Dept. of Civil & Env. Eng., Western University, London, ON, N6A 5B9, Canada
b Dept. of Civil Eng., Lakehead University, Thunder Bay, ON, P7B 5E1, Canada
*Corresponding author: [email protected]
Introduction
In electrokinetic process, electrolysis reactions at the electrodes create an acid front near
the anode and a base front at the cathode. The two fronts then move toward each other
by electroosmosis and/or electromigration creating two soil zones with opposite pH
characteristics. The impact from the advancement of the acid and base fronts in the soil
is dependent on the intended use of electrokinetics. For instance, in electrokinetic
bioremediation, the low pH in the acid front zone is detrimental to the existence of
bacteria and subsequently decreases the effectiveness of the process [1]. The acidic
medium causes the dissolution of heavy metal compounds in the soil which facilitates
the removal of the metals by electroosmsois and/or electromigration. On the other hand,
the base front on its path towards the anode reacts with the cations in the pore fluid
before they reach the cathode causing premature precipitation of the heavy metal(s) in
the soil. The premature precipitation of the heavy metals is a major drawback for
electrokinetic remediation [2]. Extensive research has aimed to hinder the advancement
of the base front and the premature precipitation of ionic species. Researchers have
investigated conventional and innovative techniques to overcome the limitation of the
premature precipitation. The most popular conventional approaches are the addition of
enhancement fluids to depolarize the cathode reaction [3-5]. The innovative techniques
include stepwise moving anode [6] and polarity exchange [2]. The field applications for
conventional approaches or innovative techniques need either the use of of chemicals
compounds or an extra field work or both. Thus, the overall cost of the remediation
process increases regardless of the improvement in the efficiency.
This study proposed a novel approach, Two Anode Technique (TAT), to hinder the base
front advancement and enhance electrokinetic remediation of soil contaminated with
heavy metal(s). Compared to conventional anode configuration (CAC) and innovative
approaches, TAT can significantly decrease the advancement of the base front without
adding a chemical compound or an extra field work.
(a) (b)
Figure 1. (a) Conventional anode configuration (CAC); (b) Two anode technique (TAT)
OH
H
Cathode
DC Power supplyMain electric circuit
Primary anode
OH
H
H
Cathode
DC Power supplyMain electric circuit
DC Power supply
Secondaryelectric circuit
Primary anode Secondary anode
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
125
Procedure
In this study, one-dimensional electrokinetic remediation was performed using an EK
cell with inner dimensions of 385×125×250 mm (lengthwidthheight). Copper(II)
chloride dehydrate was used to artificially contaminate a lean clay and simulate
common heavy metals pollution. Graphite electrodes with dimensions 200x15x6 mm
(length width × thickness), served as pair of anodes and pair of cathodes, were placed
in direct contact with the soil specimen in the electrokinetic cell. The two anodes were
placed 30 mm apart and likewise the pair of the cathodes. One DC power supply was
connected to the anode and cathode in the elctrokinetic testing cell with CAC
(Figure 1a). Two DC power supplies were connected to the graphite electrodes in the
electrokinetic testing cell with TAT (Figure 1b). ADC power supply with applied
voltage of 40V (2 V/cm) was connected to the pair of primary anodes and the pair of
cathodes (outer electric circuit) in both cells. In addition to the aforementioned power
supply, a second power supply with applied voltage of 15 V (3 V/cm) was connected to
the pair of secondary anodes and the pair of cathodes to form the secondary electric
circuit in the TAT cell as shown in Figure 1b.
Results
After the test, the soil specimen was divided into four equal sections (S1 to S4). The pH
in the soil sections after the CAC test at S1, S2, S3, and S4 are 2.0, 2.2, 7.2, and 8.5,
respectively. The pH at the end of TAT test at S1, S2, S3, and S4 are 2.2, 2.2, 2.5, and
3.5, respectively. Thus, while CAC lowered the pH of the soil to acidic levels in two
sections, TAT was effective in lowering the pH of the soil to acidic levels in all
sections. Figure 2 shows the ratio (%) of copper concentration (C/Co) in soil sections
after CAC and TAT tests with power consumption of 1250 Whr. As seen in Figure 2, in
the CAC test, 94%, 89%, and 35% of initial copper was removed from S1, S2 and S3,
respectively. In the cell with TAT configuration, 93%, 87%, and 81% of the initial
copper was removed from S1, S2, and S3, respectively. In both tests, approximately all
of the removed copper accumulated in S4.
(a) (b)
Figure 2. (a) Conventional anode configuration (CAC); (b) Two anode technique (TAT)
Conclusions
The purpose of the study was to investigate an innovative approach to hinder the
advancement of the basic front and enhance the efficiency of removing heavy metals
from contaminated soil. In CAC and TAT tests, most of the copper was removed from
sections S1 and S2. However, TAT test was successful in removing 81% of the copper
from S3 compared to 35% in CAC test. The effectiveness in removal from S3 in TAT
test resulted from the success of the technique in preventing the base front from
Soil sections (S1-S4)
Co
pp
er
C/C
o (
%)
0
50
100
150
200
250
300
Total copper in soil
Copper in soil solids
Copper in water
S1 S2 S3 S4
An
od
e
Ca
tho
de
Soil sections (S1-S4)
Co
pp
er
C/C
o (
%)
0
50
100
150
200
250
300Total copper in soil
Copper in soil solids
Copper in water
S1 S2 S3
An
od
e
S4
Se
co
nd
ary
an
od
e
Ca
tho
de
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reaching S4. The success of TAT in removing the copper from 75% of the contaminated
soil compared to 50% in the CAC tests is significant to the progress of elecrokinetic
remediation of contaminated soils. More research is needed to optimize TAT configuration for electric current and location of secondary anode.
References
[1] E.K. Nyer. In situ treatment technology. Boca Raton, Fla., Lewis Publishers
(2001)
[2] M.Pazos, M.A. Sanroman, Chemosphere 62 (2006) 817
[3] Y.B. Acar, A.N. Alshawabkeh, Environ. Sci. Technol. 27 (1993) 2638
[4] Y.B. Acar, Hamed J. T., A.N. Alshawabkeh, R.J. Gale. Geotechnique
44(1994)239
[5] A.T. Yeung, C. Hsu, Journal of Hazardous Materials 55(1997) 221
[6] X.J. Chen, Z. M. Shen, T. Yuan, S.S. Zheng, B.X. Ju, W.H. Wang, J. of Environ.
Sci. and Heal. Part a-Toxic/Hazardous Substances & Environ. Eng. 41(2006)
2517
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127
Nº REF.: P124
Determining variable importance on electrodialytic remediation of heavy metals from polluted harbour sediments
Kristine B. Pedersena,*
, Lisbeth M. Ottosenb, Pernille E. Jensenb, Tore Lejon
a
a Department of Chemistry, The Arctic University of Norway, 9019 Tromsø, Norway
b Arctic Engineering and Sustainable Solutions, Technical University of Denmark, 2800
Kgs Lyngby, Denmark
*Corresponding author: [email protected]
Harbour sediments have been exposed to a wide variety of pollutants caused by decades
of human activities in the harbours as well as on adjacent land. The need for
management of polluted harbour sediments arises either through governmental acts to
decrease the hazardous risk for human health and the environment; or through the
development of harbours in which contact with or removal of polluted sediments is
inevitable; e.g. when increasing navigational depths. The most common way of dealing
with dredged contaminated sediments is disposal at licensed landfills (on land or at deep
sea), and in some cases solidification/stabilisation of the sediments, e.g. in new harbour
constructions. In order to increase the recycling potential of contaminated sediments
there is a need to develop more cost-efficient methods for remediating to levels at which
the sediments are made available for reuse. Electrodialytic remediation (EDR) has been
proven a good method for removing heavy metals from polluted harbour sediments to
levels assessed as not posing a hazardous risk for human health and the environment
according to international recommended values from OSPAR [1-7].
The focus of this study was to contribute to the further development and optimisation of
the EDR methods in remediating harbour sediments, applying the newly developed two
compartment cells as opposed to the traditional three compartment EDR cells. In the
traditional three compartment cells ion exchange membranes separate the sediment in
suspension from the electrodes and the circulating electrolytes to prevent proton and
hydroxyl ions produced at the electrodes from entering the polluted material[8]. Water
splitting at the anion exchange membrane ensures acidification of the polluted material.
In the two compartment cells the anode is placed directly in the polluted material
compartment; maintaining the separation of the cathode from the sediment in
suspension by a cathode exchange membrane thus preventing the hydroxyl ions
produced at the cathode from disturbing the remediation process in the sediment
compartment.
The influence and relative importance of the experimental variables (current density,
remediation time, stirring rate of the sediment in suspension, liquid-solid ratio of the
suspended sediment and light/no light) on the remediation of the heavy metals
cadmium, chromium, nickel, copper, lead and zinc from polluted harbour sediments
from Sisimiut in Greenland was tested. Measurements of the metals aluminium, barium,
calcium, iron, potassium, magnesium, manganese, sodium and vanadium were made as
indicators of the changes EDR may have on the sediment matrix.
A multivariate statistical experimental design was applied ensuring that as much as the
experimental space was covered in the 8 experiments and in addition enabled the
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
128
multivariate analysis of the results for assessing the relative variable importance. This
was done by performing projection to latent structures (PLS) in which relations between
two matrices; a X matrix with independent experimental variables and a Y matrix with
the responses (i.e. remediation levels) was determined. The PLS analysis hence assess
the possible relation between the variation in the experimental variables and the
variation in the remediation levels. Results of the PLS analysis indicate the order of
relative variable importance as time>current density>>stirring rate>liquid-solid
ratio>light. For the given experimental design the most important variables for the
remediation process is time and current density.
References
[1] G. Nystroem, L. Ottosen, A. Villumsen, Sep. Sci. Technol., 40 (2005) 2245-2264.
[2] G.M. Nystroem, L.M. Ottosen, A. Villumsen, Environ. Sci. Technol., 39 (2005)
2906-2911.
[3] G.M. Nystroem, A.J. Pedersen, L.M. Ottosen, A. Villumsen, Sci. Total Environ.,
357 (2006) 25-37.
[4] K.H. Gardner, G.M. Nystroem, D.A. Aulisio, Environ. Eng. Sci., 24 (2007) 424-
433.
[5] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, J. Hazard. Mater., 169 (2009) 685-
690.
[6] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, Chemosphere, 79 (2010) 997-1002.
[7] L.M. Ottosen, G.M. Nystrom, P.E. Jensen, A. Villumsen, J. Hazard. Mater., 140
(2007) 271-279.
[8] H.K. Hansen, L.M. Ottosen, B.K. Kliem, A. Villumsen, J. Chem. Technol.
Biotechnol., 70 (1997) 67-73.
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129
Nº REF.: P127
Monitoring electrokinetics by geophysical methods: Preliminary laboratory investigations
Matteo Masia, Alessio Ceccarini
b, Maria Beatrice Ostuni
a, Reinout Lageman
c and
Renato Iannellia*
a University of Pisa, Department of Energy Engineering, Systems, Land and
Construction, Via Gabba 22, 56122 Pisa, Italy b University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy
c Lambda Consult, Schuylenburgh 3, 2631 CN Nootdorp, Netherlands
*Corresponding author: [email protected]
Monitoring of electrokinetic processes [1] both in laboratory and in field is usually
carried out by point measurements and sample collection from discrete locations.
Geophysical methods can be very effective in obtaining high space and time resolution
mapping for an adequate control of the electrokinetic processes. This study investigates
the possibility of using geophysical methods to monitor electrokinetic remediation
processes. Among several geophysical methods, we selected the induced polarization
(IP) technique because of its capability to provide qualitative and quantitative
information about the physico-chemical characteristics of the porous medium [2].
We carried out laboratory-scale electrokinetic remediation experiments on marine
sediments contaminated by heavy metals, in a prismatic acrylic cell (50x15x15 cm).
Four experiments (EXP1 to EXP4) were performed by changing the intensity of the
applied electric field and the type of conditioning agent circulated within the system to
enhance the extraction process. Tap water was used as the process fluid in EXP1 and
EXP2. To promote metal removal, a 0.1M solution of citric acid and 0.1M EDTA
solution were used in EXP3 and EXP4, respectively. The applied voltage gradients were
50 V/m (EXP1 and EXP3) and 80 V/m (EXP2 and EXP4). The treatment duration was
10 days. At the end of each experiment, the material was sampled from 5 locations and
analyzed for pH, total metal content and IP response, measured in the frequency domain
in the range 10-3
-103 Hz and deconvolved using the Debye decomposition method [3].
A linear relationship between the sample chargeability m (mV/V) and pH was found
(Figure 1). This relation can be interpreted taking into account the electrical double
layer (EDL) polarization mechanism. According to the EDL theory, a pH variation is
responsible for a change in the zeta potential of the sediment, which is proportional to
the amount of electric charge at the EDL. A variation of chargeability is thus directly
associated with an alteration of electric charge at the EDL. Such a relationship has
potential value for the interpretation of IP data during electrokinetic remediation.
Furthermore, we performed numerical simulations to assess the feasibility of measuring
the IP response with a multi-electrode tomography system (Figure 2). We developed a
synthetic model which reproduces the tomographic IP response based on the true values
measured at the end of EXP2, assuming that they only change along the x-direction
(horizontal) and they are constant along the z-direction (vertical). An array of 24
electrodes, with 2 boreholes and 1 surface array was used. We simulated 780 dipole-
dipole measurements with 2% RMS Gaussian noise, added to the data before the
inversion procedure (Levenberg-Marquardt method). The empirical linear model
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
130
coupled with the tomographic inversion procedure are able to predict the pH values of
the sediment with a RMSE error below 0.55 (at 3.5 cm depth) and 0.8 (at 9 cm depth).
These results strongly encourage the field-scale engineering implementation of the IP
method for monitoring electrokinetic processes.
Figure 1. Variation of chargeability with pH. Symbols show measured data. The line is determined
by linear regression. The fitting quality is indicated by the determination coefficient R2
Figure 2. Numerical simulations. i) Synthetic model based on data measured in EXP2, ii)
reconstruction of the synthetic model by tomographic inversion and iii) resistivity/chargeability profiles along two arbitrary horizontal lines (located at 3.5 cm and 9 cm depth, respectively).
References
[1] Acar, Y.B. and A.N. Alshawabkeh, Principles of electrokinetic remediation.
1993. 27(13): p. 2638-2647.
[2] Kemna, A., et al., An overview of the spectral induced polarization method for
near-surface applications. Near surface geophysics, 2012. 10(6): p. 453-468.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
131
[3] Nordsiek, S. and A. Weller, A new approach to fitting induced-polarization
spectra. Geophysics, 2008. 73(6): p. F235-F245.
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132
Nº REF.: P129
Membrane influence on electrodialytic remediation of air pollution control from municipal incinerated solid waste
Raimon Parés Viadera*
, Pernille Erland Jensena, Lisbeth M. Ottosen
a
a Department of Civil Engineering, Technical University of Denmark, 2800 Kongens
Lyngby, Denmark
*Corresponding author: [email protected]
Electrodialysis (ED) has been widely investigated as a technology to reduce the
leaching of metals and salts in some polluted materials, such as Municipal Solid Waste
Incineration (MSWI) Air Pollution Control (APC) [1]. Important parameters of ED like
the intensity, the remediation time or the membrane brand used have been studied on
different materials [2, 3]. However, no previous research has been done on the impact of
the membranes used when treating APC residues. This is a crucial criterion when
scaling up, because the costs of the membranes change dramatically from one brand to
another.
In the present work, four different brand membranes were used in the same
electrodialytic cell set up (Figure 1) and at the same operating conditions, treating two
different kinds of MSWI APC; one of a dry flue-gas cleaning system and another of a
wet flue-gas cleaning system.
Figure 1. Schematic view of a cell used for the ED treatment of both APC residues. AN: anion-
exchange membrane; CAT1 /CAT2: cation-exchange membranes.
The targeted metals were Al, As, Ba, Ca, Cd, Cr, Cu, Mn, Mo, Na, Ni, Pb, V, Zn,
whereas the targeted salts were chloride and sulfate. The results show that the leaching
of metals and salt from the APC residues was generally reduced for all membranes after
ED remediation. However, with a confidence limit of a 95%, the leaching of the
following elements was found to be different after ED treatment depending on the
membrane used:
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
133
- For the APC residue from the dry flue-gas cleaning system: Ca, Cr, Cu, Na, Ni, Pb,
Zn, Cl, SO4.
- For the APC residue from the wet flue-gas cleaning system: Al, Ba, Cr, Cu, Mn,
Mo, Na, Ni, V, Zn, Cl, SO4.
For some elements and membranes, the final leaching values were below the Danish
law thresholds in the reuse of waste materials in the construction industry.
References
[1] G.M. Kirkelund, P.E. Jensen, A. Villumsen, L.M. Ottosen, J. Appl. Electrochem.
40 (2010): 1049-1060
[2] P. E. Jensen, L. M. Ottosen, C. Ferreira, Electrochimica Acta, 52 (2007), 3412-
3419
[3] L.-G. Ulises, A.-L. René, O. German, T.-G. Julieta, C. Federico, Journal of Water
Resource and Protection, 3 (2011), 387-397
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
134
Nº REF.: P133
Study on removal behavior of cesium ion in clay minerals (kaolin and vermiculite) by using electrokinetic process
Yasuhiro Akemotoa, Chihiro Kitagawa
a, Ryosuke Miyamura
a, Masahiko Kan
b,
Shunitz Tanakaa,*
a Graduate School of Environmental Science, Hokkaido University, Sapporo, 060-0810,
Japan b Hokkaido University of Education Sapporo, Sapporo, 002-8502, Japan
*Corresponding author: [email protected] (Shunitz Tanaka)
Introduction
On March 11th 2011, the mega earthquake happened in Japan. This earthquake caused
the big tsunami which attacked the east coast of Tohoku area. Consequently, large
amount of radionuclides were released in environment from nuclear reactor of
Fukushima Daiichi Nuclear Power Plant (FDNPP) exploded [1]. Japan now faced to the
severe pollution in water and soil. Since 137
Cs, which is one of the radionuclides, has a
long half-time of 30 years, the effect of 137
Cs on human and environment will continue
for a long term. However, the removal of Cs ion from soil is not easy because Cs ion
might be bound strongly in the layer of some kinds of clay minerals. Especially, it is
said that vermiculite has the specific binding sites such as frayed-edge sites (FES) [2].
Electrokinetic process has a potential to remove Cs ion from contaminated soil without
destructing soil structure [3]. In this study, we investigated the removal behavior of Cs
ion in model soil by using electrokinetic process and analyzing the chemical forms of
Cs ion in model soil before and after electrokinetic process.
Experimental
Kaolin and vermiculite purchased from Wako Pure Chemical Co. (Tokyo, Japan) and
Kenis Ltd. (Osaka, Japan), respectively, were used as the model soil. In this study, an
EK cell made from acrylic resin was used as a migration chamber (3.0 cm in diameter
and 10 cm length). This EK equipment was depicted in the Figure 1. Two meshed Ti
electrodes coated with Pt were used as the electrode. The concentration of Cs in soil was
measured by AAS.
Figure 1 Schematic diagram of EKR equipment
Additionally, sequential extraction analysis was used as a fractionation method to
analyze chemical forms of Cs in soil before and after experiment. Since this method is
originally used for the fractionation of heavy metals [4], some parts of the method were
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
135
improved for analysis of Cs. Table 1 shows some fractions and chemicals used for
extraction in this study.
Table 1 Sequential extraction analysis for cesium from clay minerals
Fraction Chemical form Chemicals for fractionation
0 Water-soluble Distilled water
1 Exchangeable 1 M ammonium acetate (pH 7.0)
2 Bound to carbonates 1 M ammonium acetate (pH 5.0)
3 Bound to Fe and Mn oxides 0.04 M hydroxylammonium chloride
(25% acetic acid)
4 Bound to organic matter 30% hydrogen peroxide (pH 2.0)
3.2 M ammonium acetate (20% nitric acid)
5 Residual 0.5 M oxalic acid
Results and discussion
Figure 2-4 shows the distribution of Cs ion after EK process for 72 hours, when 0.1 M
KCl was used as an electrolyte and 10 V as the applied voltage. Vermiculite used in the
study included some organic matters, because this was for gardening. When kaolin and
vermiculite were used as a model soil, the removal efficiencies were 27.2% and 0.0%,
respectively. The removal of Cs ion was not easy from vermiculite than from kaolin. It
is said that vermiculite have a FES by drying which adsorbing and fixing Cs selectively.
But this results of EK experiments showed Cs chemical form in soil was translated from
fraction 5 (residual) into fraction 4 (bound to organic matter). It means that Cs can be
extracted from the residual part of vermiculite by applying electric potential. Figure 4
shows that the distribution of Cs ion after EK process when the vermiculite, whose
organic matters was degraded by heating at 600℃ before experiment, was used as a
model soil. In this condition, the removal efficiency was 14.7%. The chemical form of
Cs in soil can be changed by heating soil, under such condition EK method can be
appied to remove Cs from soil.
Figure 2 Distribution of Cs ions in kaolin before and after EK process
Figure 3 Distribution of Cs ions in vermiculite before and after EK process
Figure 4 Distribution of Cs ions in vermiculite which preprocessed
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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References
[1] T. Sato, J. Clay Sci. Soc. Japan 50 (2011) 26 (in Japanese)
[2] A. Cremers, A. Elsen, P. De Preter, A. Maes, Nature 388 (1988) 247
[3] Y.B. Acar, A.N. Alshawabkeh, Environ. Sci. Technol. 27 (1993) 2638
[4] A. Tessier, P. G. C. Campbell, M. Bisson, Anal. Chem. 51 (1979) 844
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
137
Nº REF.: P137
Optimization of electrokinetic treatment conditions for a metal-contaminated dredged sediment
Giorgia De Gioannisa, Angelo Marini
b,*, Aldo Muntoni
a, Alessandra Polettini
b,
Raffaella Pomib
a University of Cagliari, Department of Civil and Environmental Engineering and
Architecture, Cagliari, 09123, Italy b University of Rome “La Sapienza”, Department of Civil and Environmental
Engineering, Rome, 00184, Italy
Sediments accumulated at the bottom of rivers, lakes and seabed may become a sink of
contaminants deriving from the contribution of surface waters that receive discharges of
various liquid and solid wastes often containing hazardous compounds. Contaminants of
both organic and inorganic nature are often concomitantly present in sediments, and
have the potential of re-dissolving or migrating into the water column depending on the
prevalent chemical conditions. The decontamination processes for polluted sediments,
which typically derive from technologies developed for contaminated soils, in most
cases display poor remediation performance owing to the peculiar characteristics of
sediments (high water, salt and organic contents, significant amounts of fine materials).
For this reason, sediment remediation has not been extensively practiced until now,
therefore very few proved sediment cleanup cases and defined performance standards
are currently available. Electrokinetic (EK) remediation deserves particular attention in
the case of contaminated sediments due to its potential advantages, including the
capability of treating fine and low-permeability materials, and achieving consolidation,
dewatering and removal of salts and inorganic contaminants in a single stage.
Furthermore, the process can be applied in situ, and may thus be adopted where
decontamination is required but dredging is not.
The suitability of EK remediation to remove hazardous metals from dredged marine
sediments is currently being investigated in the Life+ SEKRET project (“Sediment
ElectroKinetic REmediation Technology for heavy metal pollution removal”). A
preliminary sediment characterization campaign was conducted during the initial stages
of the project in the study area, namely the Livorno harbor site (located in western
central Italy), where the harbor authority has to deal with ~100,000 m3 of dredged
sediments per year. The results of the characterization campaign are reported in Figure 1
in terms of total content of major elements and minor constituents in sediment.
Considering the threshold concentrations established by the Italian regulation for soil in
residential areas 0, the critical contaminants were found to include Cu, Cd and Zn; Cr
was present in sediment at concentrations slightly below the limit value. Adopting the
informal criteria defined by the Italian Ministry for the Environment 0, Ni should also
be included among the contaminants of concerns. The grain size distribution of
sediment was as follows: 18.1% coarse sand, 35.2% fine sand, 46.7% fine fraction (silt
+ clay), confirming the potential suitability of the material for the EK treatment.
The aim of the SEKRET project is testing the performance of EK remediation of
sediment at the pilot scale. To this purpose, a 150 m3 demonstration EK reactor will be
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
138
built and operated. A number of preliminary lab-scale tests are being conducted in order
to assess the feasibility of metal removal from sediment using the EK process and to
evaluate the optimal operating conditions required for the pilot-scale process. In order to
explore a wide range of process parameters, a large number of lab-scale experiments is
currently underway making use of small electrokinetic cells (5158 cm Perspex
prisms, comprising three compartments of equal volume for the electrode chambers and
sediment core) operated at constant electric current intensity. The experimental
campaign has been arranged according to a number of electrokinetic tests where
different conditions in terms of composition of the electrode solutions, applied current
density and treatment duration are investigated (see Table 1). Additional EK tests will
also be conducted in which the opportunity of a sediment pre-treatment stage (e.g.,
washing, size separation) will be evaluated, with the aim of improving the remediation
yield and/or reduce energy consumption. The EK process is monitored by
measurements of the time evolution of voltage gradient along the sediment core, pH and
metal concentrations in the electrode chambers, as well as final distribution of pH and
metal content in the solid sample at different distances from the electrodes. The analysis
of the mentioned parameters will be used as a means to investigate the underlying
mechanisms responsible for metal detachment from the solid particles and migration
along the EK cell. The contrasting effects of undesired side reactions (including
oxidation/reduction of the circulating solution, electrodeposition of metals onto the
electrode surfaces, metal precipitation within the sediment cell and change in metal
speciation during the process) will be investigated in detail, and the optimal
combination of process conditions to overcome the mentioned negative phenomena will
be evaluated.
Table 1. Summary of the experimental conditions tested
Run no.
Anodic solution
Cathodic solution
Current density (A/m2)
Duration (d)
1 H2O H2O 20 7 2 H2O HNO3 20 7 3 H2O HCl 20 7 4 H2O CH3COOH 20 7 5 H2O H2O 10 7 6 H2O H2O 10 14 7 H2O HCl 10 7 8 H2O HCl 10 14 9 H2O CH3COOH 10 7
10 H2O CH3COOH 10 14 11 H2O EDTA 20 7 12 H2O EDTA 10 7 13 H2O EDTA 10 14 14 CH3COOH CH3COOH 20 7 15 CH3COOH HCl 20 7
Figure 1. Elemental composition of the investigated dredged sediment
References
[1] Decreto Legislativo 3 aprile 2006, n. 152, Norme in materia ambientale, G.U. n.
88 14/04/2006, Supplemento Ordinario n. 96 (Italian regulatory framework on
environmental protection).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
139
[2] APAT, ICRAM, Manuale per la movimentazione dei sedimenti marini
(Guidelines for marine sediments handling), 2007.
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140
Nº REF.: P145
Effects of electrodialytic process on soil phosphorus
Núria Salvadora, Cláudia Gutierrez
b, Herink Hansen
b, Luís M. Nunes
a, Margarida
Ribau Teixeirac,
*,Pernille E. Jensend, Alexandra Ribeiro
e
aCTA, Faculty of Sciences and Technology, University of Algarve, 8005-139 Faro,
Portugal bDepartamento de Ingeniería Química y Ambiental, Universidad Técnica Federico
Santa María, Valparaíso, Chile cCENSE, Faculty of Sciences and Technology, University of Algarve, 8005-139 Faro,
Portugal dDepartment of Civil Engineering, Technical University of Denmark
eCENSE, Faculty of Sciences and Technology, New University of Lisbon, Campus de
Caparica, 2829-516 Caparica, Portugal
* Corresponding author:[email protected].
Abstract
Phosphorus (P) is an essential element for all life forms, assuming a key role in crop
growth and food production. Phosphorus has no substitute in fertilizer crops and the
main source of P applied in agriculture comes from non-renewable phosphate rocks.
Therefore, there is a global concern that P resources could be depleted in the next 50–
100 years, related to the increasing P demand to satisfy consumption rates of an
increasing global population. Eventually long-term phosphorus reserves will become
scarce, thus the challenge is to introduce alternatives to manage the P cycle before it
becomes seriously scarce. In this sense recovering, recycling and reuse phosphorus will
have to be adopted as integral parts of P management responses. Phosphorus is not
widely circulated on the globe, there is a flux from land to water but the reverse flux is
extremely limited. As a result, excessive amount of P can accumulate in water bodies
and can contribute to eutrophication. Eutrophication is caused by the overenrichment of
aquatic ecosystems with nutrients, principally phosphorus, leading to algal blooms and
anoxic environments. This event is a persistent condition of surface waters and a
widespread environmental problem, which can lead to decreases on ecosystems
services, such as losses on fish, wildlife production, and recreational amenities, and
increases in costs of water purification for human uses. To mitigate such algal blooms
much effort has been made to implement measures to reduce external loading of
phosphorus decreasing phosphorus concentrations in lake waters. However, such
approaches do not consider the roll of internal phosphorus release from sediments. In
lakes where phosphorus internal loading constitutes a considerable part of total loading,
the success of management actions requires an integrated approach of both external and
internal phosphorus loads. Reduction in internal phosphorus loading for control of algal
biomass can be achieved by various restoration approaches, either physical or chemical,
such as the removal of phosphorus-rich surface layers or by the addition of iron or alum
to increase the sediment’s sorption capacity, or by a combination of different
approaches.
This study was developed in order to evaluate the feasibility of electrodialytic
remediation (EDR) to remove and recover phosphorus from soils. Phosphorus removal
and recovery results were not as higher as expected from unpublished results, not
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
141
exceeding 2% for both removal and recovery for all experiments. Although more
research is needed, as many different mechanisms may be involved in soil phosphorus
release, this approach when combined with other remediation techniques may be useful
in controlling nutrient loading to surface waters.
Acknowledgements
Financial support for the work is provided by project FP7-PEOPLE-2010-IRSES-
269289 ELECTROACROSS - Electrokinetics across disciplines and continents: an
integrated approach to finding new strategies for sustainable development.
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142
Nº REF.: P149
Comparison of reagent to enhance desorption and mobility of arsenic in electro-kinetic remediation from contaminated paddy soil
So-Ri Ryua, Eun-Ki Jeon
a, Kitae Baeka
,b,*
aDepartment of Environmental Engineering, Chonbuk National University, 567 Baekje-
daero, Deokjin, Jeonju, Jeollabuk 561-756, Republic of Korea bDepartment of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea
*Corresponding author (K.Baek) Tel.:+82-63-270-2437; Fax:+82-63-270-244 E-mail:
Abstract
Arsenic (As) is one of toxic contaminants in the soil and groundwater, and
electrokinetic remediation has been applied to treat the As-contaminated soil. The main
mechanisms for the removal of As in the electrokinetic remediation (EKR) are electro-
migration and electro-osmotic flow [1]. In EKR system, anode generates hydrogen ions,
which acidifies the anodic region, the acidification of soil changed the surface charge
from negatively to positively. As exists as oxyanionic forms, arsenate (As(V)) and
arsenite (As(III)), in the nature, and it is well known that As(V) is adsorbed onto the soil
surface but As(III) is hardly done. In the EKR for As-contaminated soil, As(V)
desorbed into pore water will be transported toward anode because it is an anion. As(V)
transported by electro-migration will be adsorbed onto the positively charged soil
surface, which causes the decrease in As mobility. Therefore, change in the surface
charge as well as desorption of As(V) should be simultaneously considered in the EKR.
The reduction of As(V) to As(III) is one solution to solve the adsorption problem onto
soil surface because the adsorption of As(III) is much less than that of As(V). The pH
increase could change the surface charge, and As(V) and As(III) could be ion-
exchanged with hydroxyl ions [2, 3]. In this study, we investigated various enhancing
agents including extracting agents, chelating agents, and reducing agents to increase
desorption and mobility of As in the EKR of As.
Acknowledgement
This work was supported by KEITI through GAIA project.
References
[1] T. Suzuki, M. Moribe, Y. Okabe, M. Ninae, A mechanistic study of arsenate
removal from artificially contaminated clay soil by electrokinetic remediation, J.
Hazard. Mater. 254-255 (2013) 310-317.
[2] M. Jang, J.S. Hwang, S.I. Choi, Sequential soil washing techniques using
hydrochloric acid and sodium hydroxide for remediating arsenic-contaminated
soils in abandoned iron-ore mines, Chemosphere 66 (2007) 8-17.
[3] K. Baek, D.H. Kim, S.W. Park, B.G. Ryu, T. Batjargal, Electrolyte conditioning-
enhanced electrokinetic remediation of arsenic-contaminated mine tailing, J.
Hazard. Mater. 161 (2009) 457-462.
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143
Nº REF.: P150
Electrokinetic treatment of dewatered soil cake containing flocculants from soil washing processes
Su-Yeon Shin1, Sang-Min Park
1, and Kitae Baek
1, 2*
1 Department of Environmental Engineering, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea 2 Department of Bioactive Material Sciences, Chonbuk National University, 567
Baekje-daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea
*Corresponding author : Tel.:+82-63-270-2437; Fax:+82-63-270-2449; E-mail:
Abstract
Soil washing is the most common choice to remediate metals-contaminated site in
Korea [1]. In the soil washing process, the fine grained soil containing silts and clay
should be separated from the washing effluent, and flocculants is generally used in
coagulative separation for recycling of washing solution. Negatively charged soil
particles could form flocs when the cationic flocculants is used. However, the flocculent
(positive charged polymer) could produce a stable complex with arsenate(AsO45-
) and
arsenite(AsO33-
) when the soil washing process is applied to remediate As-contaminated
soil. Oxyanionic forms of As adsorbed onto the clay surfaces diffuse into internal pores
of the clay aggregates [2]. Even though enhancing agents desorb As from the residual
soil after washing process, the transport of As is retarded by the interaction between As
and cationic flocculants.
Therefore, in this study, we carried out electrokinetic remediation of dewatered soil
cake containing flocculants and arsenic in laboratory scale. The soil samples were
collected from the actual washing plant to remediate As-contaminated site, Jang-Hang,
Republic of Korea, and the dual hydrocyclone discharged three different sizes of soi
particles: 2~0.075mm, 0.075~0.005mm, and < 0.005mm. Table 1 shows the
concentration of metals and other physicochemical properties. We evaluated the
influence of cationic flocculants on the EKR of residual soil after soil washing proesses.
Table 1. Initial concentrations and characteristics of soil sample.
As
(mg/kg)
Cu
(mg/kg)
Pb
(mg/kg) pH
Water
Contents(%)
EC
(uS/cm)
CEC
(mg/100g)
Sample1
(2~0.075mm) 4.8 7.5 10.4 6.4 15.9 107.2 0.8
Sample2
(0.075~0.005mm) 90.7 119.8 253.9 6.5 34.3 245.1 21.9
Sample3
(0.005mm under) 52.7 124.3 147.9 6.5 37.7 442.0 25.6
Acknowledgement
This work was supported by KEITI through GAIA project.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
144
References
[1] C.S. Jeon, J.S. Yang, K.J. Kim, K. Baek, Electrokinetic removal of petroleum
hydrocarbon from residual clayey soil following a washing process, Clean-Soil
Air Water 38 (2010) 189-193.
[2] Z. Lin, R.W. Puls, Adsorption, desorption and oxidation of arsenic affected by
clay minerals and aging process, Environmental Geology 39 (2000) 753-759
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
145
Nº REF.: P155
Fibers ion exchange for improvement of electrokinetical removal of heavy metals from polluted sites
B. Belhadj 1, D.E.Akretche
1*, C.Cameselle
2
1Laboratory of Hydrometallurgy and Molecular Inorganic Chemistry, Faculty of
Chemistry, University of Science and Technology Houari Boumediene,USTHB, B.P. 32
El – Alia, 16111 Bab – Ezzouar, Algeria 2Department of Chemical Engineering, University of Vigo.Rua Maxwell s/n, Building
Fundicion. 36310 - Vigo. Spain
*corresponding author : email [email protected] and [email protected]
In a previous work, [1] it has been shown that fibers ion exchange can be used in
electroremediation processes with success regarding the ion to be removed. Fibers ions
exchange have been tested playing the same role of ion exchange membranes. However,
they are based on a cellulosic structure which induces hydrophilic properties. Thus, they
have shown a good mechanical structure and they have enhanced the osmosis flux with
a better selectivity against ions less hydrated as lead. Polluting products such as heavy
metals are very difficult to eliminate completely and usually, low metal concentration
remains in the effluents. In effect, electrokinetic remediation is one of in situ processes
that was been developed for metal removal. Depending on the nature and the
concentration of the heavy metals, different processes were reported to improve the
efficiency of the electrokinetic treatment. The use of anion and/or cation exchange
membranes allows controlling the transport of ions in and out of the solid of fluid to be
treated. Thus, several authors [2-6] reported the advantages of using ion-exchange
membranes in the electrokinetic treatment of soils and wastes. To improve the process,
other materials can be tested in this field. Ion-exchange fibers have been used first as a
suppressor of the packed material in columns for ion exchange chromatography,
improving the baseline stability and decreasing ion-exclusion effects and chemical
reactions [6]. The use of fibers was favored by their high separation capacity, fast ion
exchange rates and good electrical conductivity [7].
In this work, the behavior of FIBAN ion-exchange textiles was tested for the
transportation under the effect of a constant DC electric current for two heavy metals:
lead and zinc. Detailed characterization of fibers has been carried out in order to
determine the effect of their structure on heavy metal transport. Ion-exchange fibers
structure was studied by electronic scan microscopy (SEM), X-ray fluorescence (XRF),
spectrogammametric analysis and FTIR Spectroscopy/Attenuated Total Reflectance.
HITTORF model was used to determine the transport number of Pb2+
and Zn2+
during
the electrokinetic treatment. fibers ion exchange are studied to examine their role as an
alternative to the membranes. Fibers ion exchange have better mechanical properties
than membranes and they have an ion-exchange capacity more interesting with the
particular characteristic of being hydrophilic materials which permit the mobility of ions
inside them, and that mobility is comparable to that in aqueous solutions.
A plexiglass cell for the determination of the transport number is used for these tests. It
is divided in three compartments of equal volume (0.1 L each compartment). Fibers ion
exchange were inserted between compartments: anionic exchange textile on the
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146
cathodic side and cationic exchange textile on the anodic side. The main electrodes
(anode and cathode) are located on both sides of the cell. The distance between the
electrodes is 20 cm. A graphite sheet of 3.14 cm2 was used for the anode and the
cathode. The cell compartments were filled with lead(II) or zinc(II) nitrate solution at
the concentration of 10-3
or 10-4
M. A DC power supply was used to apply a constant
DC electric current in each experiment for 4 h. The selected values were: 10, 20, 30 and
40 mA. Experiments were carried out at room temperature which is around 298 K. A
conventional cell is used for electroremediation tests. Ion concentration in solution was
determined by a Unicam 929 Atomic Absorption Spectrophotometer.
Results obtained have shown that a classical electroremediation of soils polluted by
heavy metals can be improved by using fibers ion exchange in comparison to ion
exchange membranes. In this case, the osmotic flow is also favoured regarding the
hydrophilic properties of these materials.
References
[1] L.M.Ottosen, H.K.Hansen, S.Laursen, A.Villumsen, Environ. Sci.Technol.,
(1997),31(6),1711.
[2] A.B.Ribeiro, J.T.Mexia., J Hazard Mater, (1997), 56, 257.
[3] H.K.Hansen, L.M.Ottosen, K.B.Kliem, A.Villumsen, J.
Chem.Technol.Biotechnol., (1997),70, 67.
[4] L.M.Ottosen, H.K.Hansen, C.B.Hansen, J Appl.Electrochem, (2000), 30, 1199.
[5] A.B.Ribeiro, E.P.Mateus, L.M.Ottosen, G.B.Nielsen, Environ.Sci.Technol.,
(2000), 34(5), 784.
[6] M. Vuorioa, J.A. Manzanares, L. Murtomakia, J. Hirvonen, T. Kankkunen, K.
Kontturi, J. of Controlled Release 91 (2003) 439.
[7] L. Chen, G.Yang, J. Zhang, React. Funct.Polym. 29 (1996) 139.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
147
Nº REF.: P160
Electrical behavior of copper mine tailings during EKR with modified electric fields
Adrian Rojoa*
, Henrik K. Hansena,
,Omara Monárdeza, Carlos Jorquera
a
aUniversidad Técnica Federico Santa María, Valparaíso, casilla 110-V Chile
*Corresponding author: [email protected]
Introduction
Electrokinetic remediation (EKR) is an in-situ treatment technology for restoration of
contaminated hazardous waste sites [1].The conventional application of this alternative
treatment uses direct current (DC) applied across electrodes inserted in the soil to
generate an electric field for the mobilisation and extraction of contaminants [2]. In the
case of waste from copper mining, previous work [3] has shown that the conventional
DC system was limited with regard to metal removal efficiency and had very high
electrical energy consumption.Under this scenario sinusoidal EKR was applied by an
electric field through the simultaneous application of DC and AC voltages [4,5].
In general, experiments have shown that the use of a sinusoidal electric field favoured
overall copper removaland specific energy consumption in the EKR cell [6],and
particularly good results were observed when this type of electric field produce
periodical polarity reversal inthe electrodes. However, special phenomena have been
observed associated with high frequency of the AC voltage, which require better
understanding of the electrical behaviorof the tailing when EKR with a sinusoidal
electric field of the type mentioned above is applied.
Experimental
Six EKR experiments results with a remediation time of 7 days were analyzed. In this
case, a synthetic waste was prepared with fine sand, copper concentrate (chalcopyrite)
and copper sulfate pentahydrate, to obtain a mixture containing 1000 ppm of total
copper from which 400 ppm are soluble. In all experiments, a sample of approximately
1.6 kg solid dry weight of the above synthetic waste was adjusted to an initial humidity
of 20%, using sulfuric acid solution. The modified electric field in pulses was obtained
by applying simultaneously continuous-alternating (DC-AC) voltages with an external
power supply. The EKR experimental setup is shown on Figure 1 and the experimental
originals conditions are given in Table 1.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
148
Figure 1. Experimental setup
Table 1 Summary of the experimental conditions.
Exp. Applied potential V (V) Frequency fVAC (Hz) Pulses ON/OFF (s)
DC AC Veffective Vmaximun Vminimun
1 20 -- 20 20 20 -- --
2 10 15 14.6 25 -5 50 25 (2500/100)
3 10 15 14.6 25 -5 500 25 (2500/100)
4 10 15 14.6 25 -5 1000 25 (2500/100)
5 20 25 26.7 45 -5 1000 25 (2500/100)
6 20 15 22.6 35 5 1000 25 (2500/100)
7 10 15 14.6 25 -5 2000 25 (2500/100)
8 20 25 26.7 45 -5 2000 25 (2500/100)
9 10 15 14.6 25 -5 1000 20 (2000/100)
Results and Discussion
Sinusoidal EKR with voltages in Volts, VDC/VAC= 10/15, producing an effective voltage
of 14.6 [V], show a steady increase inthe removal ofcopper (total and soluble) if the
frequency of the AC voltage increases from 0.05 to1 kHz, but increased to 2 kHz
removal was negligible.The same effect was observed for the experiments with
VDC/VAC = 20/25, Veffective = 26.4 [V], in terms of getting a negligible removal going
from 1 to 2 kHz. Table 2 shows he results associated with this observation.
Table 2. Overall removals of total and soluble copper, frequency AC Voltage effects, for Veffective 14.6 and 26.4 (V). Pulses time ratio 25.
Exp. Frequency fVAC (kHz) Veffective (V) Overall removal (%)
Total copper Soluble copper
2 0.05 14.6 3.1 5.8
3 0.5 18.0 31.9
4 1 24.5 47.9
7 2 0.4 1.0
5 1 26.4 21.5 55.3
8 2 -0.5 -1.3
Conclusions
For the conditions selected in this discussion, in sinusoidal EKR experiments with
simultaneous application of DC and AC voltages, the conclusions are:
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
149
When the frequency of the AC voltage reaches 2 kHz, tailings sample behaves
as a frequency filter. For this application could give 2 types of filters: a low pass
and a high pass.
In this case it is a high pass filter, which removes or attenuates all frequency
components bellow a frequency threshold. So in the experiments 7 and 8, the
removed DC voltage (zero frequency) does not produce thenetchargeto promote
electrokinetic phenomenafor remediation, and only the AC voltage was applied
to the sample, and for this reason the removal process was negligible.
References
[1] Y.B. Acar, A.N. Alshawabkeh, Environ. Sci. Technol. 27 (1993) 2638
[2] R.F. Probstein, R.E. Hicks, Science 260 (1993) 498
[3] A. Rojo, H. K. Hansen, L. M. Ottosen, Minerals Engineering, 19(2006) 500
[4] A. Rojo, H. K. Hansen, M. Agramonte, Sep. and Pur.Technology, 79(2011) 139
[5] A. Rojo, H. K. Hansen, M. Cubillos, Electrochimica Acta, 86(2012), 124
[6] A. Rojo, H. K. Hansen, O. Monárdez, Minerals Engineering, 55(2014), 52
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
150
Nº REF.: P165
Study of electrokinetic remediation technology at semi-pilot scale. Strong acid enhancement
M. Villen-Guzmana,*
, G. Amaya-Santosa, A. García-Rubio
a, C. Vereda-Alonso
a,
J.M. Rodriguez-Marotoa, J.M. Paz-García
b
a Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain
b Division of soil mechanics, Lund University, Lund, 22363, Sweden
*Corresponding author: [email protected]
In this work acid-enhanced EKR experiments at semi-pilot scale were carried out. The
soil, collected from the ceased mining district of Linares (Spain), is a clay-loam soil
with low permeability. In these cases, in which soils are clayey, the application of
electrokinetic remediation should be considered. It is also widely accepted that EKR
requires the use of some kind of enhancement. The most typical enhancement method
consists in the neutralization of the alkaline front generated at the cathode by the
addition of an acid to the catholyte [1, 2].
We have chosen the BCR (Bureau Commuautaire de Référence) as a speciation analysis
[3, 4]. This procedure consists in a sequential extraction procedure (SEP) that divides
the total metal content into several fractions. The used of this SEP in a “before and
after” way, provides information not only about the total concentration of the target
contaminants, but also about the changes on the mobility of the contaminants due to the
applied treatment.
Figure 1 schematically shows the experimental system. The experiments were
performed in two methacrylate columns holding, about 2000 g of saturated soil, each.
The catholyte and anolyte solutions were continuously pumped from independent
vessels of about 500 ml into the corresponding electrode compartment and allowed to
flow back to the vessels, without pressure gradient between the two compartments. The
pH value of the catholyte vessel was kept constant, at the target values 4 and 5 by
addition of nitric acid. At selected time steps, samples were obtained for metal analysis.
The columns were electrically connected in series in order to assure that the same
electrical charge flows through them. At the end of the experiments the soil of each
column was divided into ten slices. The pH, water content, metal concentrations (Ca,
Cu, Fe, Mg, Mn, Pb) and BCR speciation were determined for each of these slices.
Figure 1. Outline of the experimental system.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
151
In general, results reveal that the concentration of metals in the soil close to the anode
compartment decrease during the experiment. Figure 2 shows the percentage of Mn
obtained by the BCR speciation after the soil treatment and for the initial soil. As it can
be seen the Mn associated with the two more bioavailable BCR fractions (WAS and
Reducible) has been removed in the soil close to the anode compartment. This is in
agreement with the fact that when the concentration of Mn decreased in the soil, the
concentration of lead in the RED fraction also decreased, since this fraction is related to
the metal adsorbed onto Fe/Mn oxides.
Figure 2. BCR results for the strong acid enhancement (pH-4)
The metal concentration analysis of each fraction obtained following the BCR method
is of great importance to better understand the behaviour of the main contaminant, lead.
References
[1] Y.B. Acar, A.N. Alshawabkeh, Environ. Sci. Technol. 27 (1993) 2638
[2] A.T Yeung, Y.Y Gu. . J. Hazard. Mater. 11 (2011)195
[3] G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, R. Rubio, C. Davidson, A. Ure, Ph.
Quevauviller. J. Environ. Monit. 1 (1999) 57
[4] G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, E. Barahona, M. Lachica, C.
Davidson, A. Ure, A. Gomez, D. Lück, J. Bacon, M. Yli-Halla, H. Muntau, Ph.
Quevauviller. J. Environ. Monit. 2 (2000) 228.
Acknowledgements
Authors acknowledge the financial support provided by the Spanish Ministry of
Innovation and the FEDER fund of the EU through the Research Project ERHMES,
CTM2010-16824 and the UE project Electroacross IRSES-GA-2010 269289. Villen-
Guzman also acknowledges the FPU grant obtained from the Spanish Ministry of
Education, Culture and Sport. We also appreciate very much the help of Prof. Carmen
Hidalgo Estevez from the University of Jaen for her advice in the selection and
sampling of the contaminated soils.
0%
20%
40%
60%
80%
100%
120%
140%
160%
Initial 1 2 3 4 5 6 7 8 9 10
% M
n
RES OXI RED WAS
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
152
Nº REF.: P167
A critical study of the use of the BCR speciation for the characterization of mobilizable metal contamination
Villen-Guzman, M.a*
, Amaya-Santos, G.a, Garcia-Rubio, A.
a, Paz-Garcia, J.M.
b,
Garcia-Herruzo, F.a, Gomez-Lahoz, C.
a
a Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain
b Division of soil mechanics, Lund University, Lund, 22363, Sweden
*Corresponding author: [email protected]
The sequential extraction procedures (SEPs) for heavy metals speciation in
contaminated soils are obtaining increasing attention. These analytical procedures are
performed as a tool for the risk assessment and the feasibility studies of the recovery
techniques. The need of this kind of tool arises from a balance between two facts: First,
the use of analytical techniques that obtain the total concentration implies that all forms
of a heavy metal have an equal impact on the environment and this supposition is
clearly refuted. On the other hand, soil contamination usually involves such a
complexity that it would be impossible to establish each species with detail. SEPs study
the behaviour of all the species present upon the addition of specific extracting agents.
In this work, it has been studied the BCR (Bureau Communautaire de Référence) [1] as
a SEP to determine the mobility of lead and other heavy metals in the contaminated soil
from the mining district of Linares (Spain). In addition to that, the simulation of the
experimental results was performed using the freeware chemical equilibrium speciation
software Visual MINTEQ. In brief, the BCR uses three sequential steps: The sample is
first treated with acetic acid to release the exchangeable and the acid-extractable metals;
this step is denominated the weak-acid soluble fraction (WAS). Then, the remaining
solid phase is separated by centrifugation and a solution of hydroxylamine
hydrochloride is used to solubilize the metals associated with the reducible fraction. In
the third sequential step, the second step residue is treated with hydrogen peroxide, to
obtain the oxidizable fraction. Usually a fourth step is also performed in which the
residue of step three is digested with aqua regia, to obtain the residual fraction. This
fourth step allows the comparison of the results obtained in each step with the
pseudototal content of each metal in the soil that can be obtained by the digestion of the
original soil. On the other hand, the simulation procedure, considers the possible
different lead species according to the main cations and anions present in the soil (Ca,
Mg, Fe, Mn, carbonates, etc), and then reproduces the BCR fractionation of the lead in
the soil by the chemical software.
As can be seen in Figure 1, which shows experimental and simulation results for the
conventional BCR (BCRx1) and modified BCR (BCRx2) of the original soil, the
simulation adequately predicts the distribution of Pb between the BCR fractions.
According to the model, if the WAS fraction of the BCR is repeated, a significant
additional amount of Pb will be extracted. The simulation results for this modified
procedure predict a 20% increase of the WAS fraction relative to the one obtained in the
simulation of the conventional BCR method. This behaviour is also confirmed by the
experimental model results which show that the relative amount of Pb associated with
the WAS fraction increases from (63% ± 4%) in the conventional BCR procedure to
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
153
(75% ± 4%) in the modified BCR procedure with the repetition of the WAS extraction.
Besides that, experiments with a modified version of BCR in which the first step (Weak
Acid Soluble, WAS) was repeated until the pH value of the extractant was similar to
that of the initial extracting solution, showed that when the pH value after the extraction
is not close to that of the acid acetic solution, the WAS fraction, as defined by BCR,
undervalues the amount extractable by acid, and this additional acid-soluble amount is
recovered in the following fractions.
Figure 1. Experimental and simulation results for the conventional (BCRx1) and modified
(BCRx2) sequential extraction of the initial soil
The information obtained is relevant to the studies of electrokinetic remediation
technologies. The good agreement between the experimental and simulation results
indicates that the chemical system selected for the description of equilibrium process in
which Pb is involved is correct.
References
[1] G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, E. Barahona, M. Lachica, C.
Davidson, A. Ure, A. Gomez, D. Lück, J. Bacon, M. Yli-Halla, H. Muntau,Ph
Quevauviller. J. Environ. Monit. 2 (2000) 228.
Acknowledgements
Authors acknowledge the financial support provided by the Spanish Ministry of
Innovation and the FEDER fund of the EU through the Research Project ERHMES,
CTM2010-16824 and the UE project Electroacross IRSES-GA-2010 269289. Villen-
Guzman also acknowledges the FPU grant obtained from the Spanish Ministry of
Education, Culture and Sport. We also appreciate very much the help of Prof. Carmen
Hidalgo Estevez from the University of Jaen for her advice in the selection and
sampling of the contaminated soils.
0%
20%
40%
60%
80%
100%
Pb WAS RED OXI RES
Model
Experimental
BCR x1
Model
Experimental
BCR x2
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
154
Nº REF.: P169
Study of efficiency in the removal of lead from soil by different treatments
M. Villen-Guzmana, G. Amaya-Santos
a, A. Garcia-Rubio
a,*, J.M. Paz-Garcia
b,
J.M. Rodriguez-Marotoa, and F. Garcia-Herruzo
a
a Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain.
b Division of Solid Mechanics, Lund University. Lund, 223 63 Sweden
*Corresponding author: [email protected]
In this work, different extractant agents are evaluated to establish their efficiency in the
removal of the total Pb concentration of different soils from the mining district of
Linares (Spain). Furthermore, a speciation analysis is used to compare the mobility of
lead before and after the use of each extractant.
The possible application for soil electrowashing was explored, after the kinetic study of
these extractant agents.
Four samples of soils were treated:
o Soil with a very high lead concentration ([Pb]=45000 ppm), called “SC”
o Soil with a less concentration of lead ([Pb]=2700 ± 400 ppm), called “SL”
o Spiked soil. This is SL soil spiked to amount a similar concentration to SC. This
soil is stored in containers; some of them are closed (“SLC T”, [Pb]=41500 ±
3300 ppm) and the others without cover (“SLC ST”). A cylinder of SLC ST is
obtained and this cylinder is divided into three sections:
o the deepest section, width of 1 cm, that is denominated here “SLC ST1”
o the middle section, width of 1,5 cm, that is denominated here “SLC ST2”
o the most superficial section, width of 1.5 cm, that it is denominated here
“SLC ST3” ([Pb]=111800 ± 11000 ppm). Only SLC ST3 was treated in
this experimental procedure.
The first assays to remove lead consist of the mixture of 8 g of the dry soil with 24 mL
of an extraction solution (EDTA 0.1M or Citric Acid 0.1M). This mixture is agitated for
24 hours (equilibrium time). Then, the remaining solid phase is separated by
centrifugation and the solutions mentioned above are added again to solubilize the
remaining metals in the soils. The whole procedure is repeated until five extractions are
obtained. The metal concentration of each supernatant is determined by AAS.
The results are shown in the following figure:
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
155
Figure 1. Results of extraction assays.
After that it was proved that EDTA solution and Citric Acid solution remove 100 % of
Pb from the soils, several batch extraction tests were performed in order to know the
kinetics of the processes [1]. Besides, several electrowashing experiments were
performed to compare the efficiency and leaching rate with and without current.
The washing and electrodialytic washing experiments are achieved in agitated tank,
where 400 g of dry soil are mixed with 1200 mL of solution (EDTA 0.1 M). At selected
times samples are taken from the tank for Pb concentration measurements in the
supernatant liquid. The difference between both experiments is the installation of
electrodes in the tank to create an electrical potential difference. Also, a cationic
exchange membrane (CEM) is placed around the cathode.
References
[1] J.D. Subirés-Muñoz, A. García-Rubio, C. Vereda-Alonso, C. Gómez-Lahoz, J.M.
Rodríguez-Maroto, F. García-Herruzo, J.M. Paz-García. Separation and
Purification Technology, 79 (2011) 151.
Acknowledgements
Authors acknowledge the financial support provided by the Spanish Ministry of
Innovation and the FEDER fund of the EU through the Research Project ERHMES,
CTM2012-16824 and the UE project Electroacross IRSES-GA-2010 269289. Villen-
Guzman also acknowledges the FPU grant obtained from the Spanish Ministry of
Education, Culture and Sport. We also appreciate very much the help of Prof. Carmen
Hidalgo Estevez from the University of Jaen for her advice in the selection and
sampling of the contaminated soils.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
156
Nº REF.: P174
Two step electrodialytic remediation of soil suspension for simultaneous removal of As and Cu
Lisbeth M. Ottosena,*
, Pernille E. Jensena, Gunvor M. Kirkelund
a
aARTEK, Department of Civil Engineering, Technical University of Denmark, 2800
Lyngby
Introduction
Simultaneous removal of As and Cu from soil during electrochemical treatment is not
straightforward. To have successful, simultaneous removal As and Cu they must desorb
during the remediation process and be present in ionic form in the soil solution. Cu is in
ionic form in an acidic environment regardless oxidation status of the soil. As is also
desorbed under acidic conditions [1,2], but the redox status is highly important for the
As speciation. Table 1 shows a generalized pattern for Cu and As being charged and
mobile for electromigration under different pH and redox conditions.
Table 1. Generalized pattern for Cu and As speciation
pH Redox Cu As
Acidic Low Ionic form As(III) uncharged
Alkaline High Precipitated As(V) charged
Acidic High Ionic form As(V) uncharged highly acidic, charged moderately acidic
Alkaline Low Precipitated As(III) uncharged moderately until slightly alkaline, charged
highly alkaline
Without use of assisting agents it is not possible to remove Cu from the soil. Under
acidic conditions it is only possible to remove As at in an environment with high redox
potential at a moderately low pH as (H2AsO4-). The present work is focused on
obtaining such optimal condition for electroremediation by a two-step electrodialytic
method. Figure 1 shows the two steps tested in the present investigation.
Figure 1. The two steps for simultaneous As and Cu removal. The anode is first placed directly in
the soil suspension (I) and after a period of time a separate anode compartment is added.
In the first step (2C) the anode is placed directly into the soil suspension. The anode
process H2O → 2H+ + ½ O2 (g) + 2e
- will result in an acidic environment with a high
redox potential just as needed for the simultaneous removal of As and Cu. Cu is
removed into the catholyte in setup (I), but As remains dissolved in the suspension in
2C, thus the second step (2C-3C) is needed for a separation of As into the anolyte.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
157
In the preliminary test of the two-step electrodialytic remediation two experiments were
conducted with soil sampled at a wood preservation site. Initial concentrations were 710
mg As/kg and 1500 mg Cu/kg. The experiments were:
2C; Cell (I) for 2 days
2C-3C; Cell (I) for 2 days and cell (II) for 7 days
The experimental cells were cylindrical (internal diameter 8 cm, length of electrode
compartments 5 cm and compartment with ash suspension 10 cm) The ion exchange
membranes were from Ionics. The platinum coated electrodes from Permascand. A
constant current of 10 mA was applied. Circulating in the electrode compartments 500
mL adjusted to pH 2 with HNO3. The soil was kept suspended by an overhead stirrer.
During the experiments, the pH was adjusted manually in the cathode compartment to
between 1 and 2 once a day with 1 M HNO3. A constant current of 10 mA was applied.
Figure 2. (a) pH of the soil suspension in the experiments and (b) Distribution of Cu and As in the
system after the two experiments.
Overall results from the experiments are in figure 2. During two days in 2C pH
decreases from 6 to 3 and after adding the anode compartment to the cell (2C-3C) pH
remains rather stabile at 3.5 (fig. 2a). The distribution of As and Cu at the end of
experiments (fig. 2b) shows that after two days in 2C, the major fraction of As is still
adsorbed, whereas already after 2 days 80% Cu was removed into the catholyte, and the
Cu remediation was actually sufficient to reach the Danish limiting value. When
combining 2C and 2C-3C As desorption continued during the 3C period, and almost all
desorbed As was transported into the anolyte. However, 64% As remained in the soil.
This initial result is encouraging. The Cu remediation already finished after 2 days in
2C. Too little As was desorbed, but the separation of dissolved As into the anolyte was
very efficient. As desorption is only sufficient (90-100%) at pH of about 1 in a
suspension [1, 2] so in coming experiments the period in 2C will be longer to reach this
pH. In the following 3C the aim is then first to remove H+ into the catholyte in the
applied electric field, so suspension pH increases to a level, where As is mobile.
References
[1] L.M. Ottosen, P.E. Jensen, H.K. Hansen, A.B. Ribeiro, B. Allard, B. Sep. Sci.
Technol. 44(10) (2009) 2245
[2] T.R. Sun, L.M. Ottosen, P.E. Jensen, G.M. Kirkelund, G.M. J. Haz. Mat. 203-204
(2012) 229
0
1
2
3
4
5
6
7
0 5 10
pH
in s
usp
en
sio
n
Time (d)
2C
2C-3C
0
10
20
30
40
50
60
70
80
90
100
As (2C) Cu (2C) As (2C-3C) Cu (2C-3C)
Dis
trib
uti
on
(%
)
Cathode
Soil
Liquid
Anode (3C)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
158
Nº REF.: P177
The effects of composting, biosurfactant and freezing-thawing on electrokinetic removal of heavy metals in sewage sludge
Qishi Luoa,*
, Lei Dongb, Rongbing Fu
a, Jie Gao
a, Jing Wang
a, Ming Zhang
b
a State Environmental Protection Engineering Center for Urban Soil Contamination
Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai,
200233, P R China b College of resource and environmental Science, East China Normal University,
Shanghai, 200062, P R China
*Corresponding author: [email protected]
It is quite necessary to remove the heavy metals in sewage sludge before being reused
as a resource. Electrokinetics has been proven to be an effective way to remove the
heavy metals in sludge when it is properly applied. Sludge pre-treatment is always
needed for a higher electrokinetic treatment of sludge. Three pre-treatment techniques
including composting, bio-surfactant treatment, and freezing-thawing were adapted to
explore their effects on electrokinetic removal of heavy metals from sewage in present
work. The bench scale tests showed that: (1) Pre-treatment of sludge through
alternatively freezing and thawing increased the potential availability of heavy metals in
sludge, and raised the electrokinetic removal of Cu、Zn、Cd and Ni, with an efficiency
of 62%, 80%, 44% and 39%, respectively; (2) Sludge pre-treatment with a bio-
surfactant saponin raised the desorption of heavy metals, and produced a higher
electrokinetic removal efficiency of Cu、Zn、Cd and Ni in sludge, 115%, 167%, 134%
and 113%, respectively; (3) However, composting of sludge, as a whole, reduced the
efficiency of electrokinetic treatment, due to the induced stabilization of heavy metals in
sewage sludge; (4) Furthermore, the electric consumption was raised by 76%, 287%,
28% during the test period of 6 days, for the electrokinetic system of sludge pre-treated
with freezing-thawing, saponin, and composting, respectively. The above findings
demonstrated that freezing-thawing might be a preferable pre-treatment technique for
enhanced electrokinetic treatment of sewage sludge.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
159
Nº REF.: P178
The use of 2D non-uniform electric field to remediate chromium-contaminated soil from an abandoned industrial site with permeable
reactive composite electrodes
Rongbing Fu*, Zhen Xu, Qishi Luo, Xiaopin Guo
Shanghai Academy of Environmental Sciences, Shanghai, 200233 and P. R. China
*Rongbin Fu: [email protected]
Electrokinetic remediation has shown the potential for effective removal of heavy
metals from soil [1]. However, traditional one-dimensional electrode systems limited
their widespread application because of a large part of ineffective electric field in the
system [2]. This study was conducted to improve chromium removal from contaminated
soil from an abandoned industrial site in a bench-scale electrokinetic (EK) system with
permeable reactive composite electrodes (PRCEs) in a hexagonal configuration. The
experiments were performed under a constant voltage gradient of 1.5v/cm in an EK
reactor. (diameter:1 m, depth:20 cm) over 60 days(Figure 1). The initial concentrations
of Cr (VI) and Cr (III) were 816.05 and 4352.12 mg/kg, respectively.
The pH, removal efficiencies, speciation of Cr and ineffective area in the EK reactor
were investigated. Results shows that, EK treatment led to 67.82~91.23% Cr (VI) and
89.72% of Cr(III) removals over 60 days. The ineffective area was approximately
0.1875 m2 and it accounted for 12.5 % of the total soil area which was much lower than
that of the traditional one-dimensional system (~50%) [3]. The changes of pH and
concentrations of Cr followed similar trends with the electric field strength. PRCEs
played an important role in soil pH control (3.5~4.7, after 60 days of remediation). In
addition, the composite anode transformed Cr (VI) into less toxic Cr(III) by the reaction
of Fe(0) with Cr(VI) [4].
This remediation system has three major advantages: (i) The hexagonal two-
dimensional electrode configuration enhanced the removal efficiency by minimization
of the inactive area of the electric field. (ii) Composite electrodes effectively controlled
soil pH. Moreover, heavy metal could be removed by unplugging these electrodes from
the soil. (iii) Additional chemicals and complex equipment were not required.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
160
Figure 1. Schematic illustration of experimental set-up(a) and sampling points (b)
References
[1] Y.B. Acar, A.N. Alshawabkeh, Environ. Sci. Technol. 27 (1993) 2638
[2] A.N. Alshawabkeh, R.J. Gale, E. Ozsu-Acar, R.M. Bricka, J. Soil Contam. 8
(1999) 617
[3] W. Kim, G. Park, D. Kim, H. Jung, S. Ko, K. Baek, Electrochimica Acta, 86
(2012) 89
[4] R. Fu, F. Liu, C. Zhang, J. Ma, Environ. Eng. Sci, 30 (2013) 17
Poster Session: Fundamentals and Modeling
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
163
Nº REF.: P217
Numerical analysis of vanadium and water crossover effects in all-vanadium redox flow batteries
Kyeongmin Oh and Hyunchul Ju*
Department of Mechanical Engineering, Inha University, 100 Inha-ro, Nam-Gu,
Incheon, 402-751, Republic of Korea
*Corresponding author: [email protected]
Recently, all-vanadium redox flow batteries (VRFBs) using different oxidation states of
vanadium ions as both negative and positive electrolytes have received considerable
attention for large-scale energy storage system. The main electrochemical reactions and
species transport are schematically shown in Fig. 1.
Figure 1. A schematic of vanadium redox flow battery structures and reactions in each electrode.
However, crossover of vanadium ions and resultant side reactions still hinders the
commercialization of VRFB. The capacity loss during charging and discharging process
due to vanadium ion crossover is continuously reported [1-3], implying the periodical
electrolyte rebalancing and system maintenance are inevitably required for long-term
VRFB operations.
Figure 2. Vanadium ion crossover and resultant side reactions in VRFB
As shown in Fig. 2, vanadium ions move through the membrane to opposite electrodes
and reacts with originally existent species by side reactions reducing the concentration
of charged species. Once the vanadium ions in the negative electrode, V2+
, V3+
transport
across the membrane, the following side reactions can occur in the positive electrode:
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
164
(1)
(2)
On the other hand, the crossover of VO2+
and VO2+ from the positive to negative
electrodes results in the following side reactions in the negative electrode, i.e.
(3)
(4)
It is evident that the crossover of vanadium ions through the membrane and resultant
side reactions cause an imbalance in vanadium ions between the negative and positive
electrodes, which gives rise to loss of capacity. Consequently, consumption of charged
species slows down the rate of charging process and accelerates the discharging process.
In this work, a crossover model is newly developed to account the crossover of
vanadium ions through the membrane and resultant side reactions occurring in both
positive and negative electrodes. The crossover model is then numerically coupled with
previously developed three-dimensional (3-D), transient, thermal VRFB model [4].
Using the comprehensive VRFB model, we investigate the effects of vanadium
crossover between the negative and positive electrodes during a single
charge/discharging cycle. Numerical simulations successfully capture the capacity loss
related to vanadium crossover, clearly showing the difference in species distributions
due to side reactions. The result shows that more charging time and less discharging
time have been achieved due to effect of vanadium ion crossover.
Figure 3. Voltage curves during charging and discharging process.
References
[1] E. Wiedemann, A. Heintz, R.N. Lichtenthaler, J. Membrane Science 141 (1998)
215
[2] C. Sun, J. Chen, H. Zhang, X. Han, Q. Luo, J. Power Sources 195 (2010) 890
[3] K.W. Knehr, E. Agar, C.R. Dennison, A.R. Kalidindi, E.C. Kumbur, J.
Electrochem. Soc. 159 (2012) A1446
[4] K. Oh, H. Yoo, J. Ko, S. Won, H. Ju, Energy, accepted.
2 2
2 2V 2VO 2H 3VO H O 3 2
2V VO 2VO
2 2 3
22 2VO V H V H O 2 3
2 2VO 2V 4H 3V 2H O
Poster Session: Scaling up and field applications
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
167
Nº REF.: P305
The scale up of the flushing-fluid-assisted electrokinetic remediation of kaolin soil polluted with phenanthrene
P. Cañizares 1,
*, R. López-Vizcaíno1, C. Risco
1, C. Saez, L. Rodriguez
1, J.
Villaseñor1, V. Navarro
2, M.A. Rodrigo
1
1 Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies
& Institute of Chemical and Environmental Technology, Ciudad Real, 13071 SPAIN 2
Geoenvironmental Group, Civil Engineering School, University of Castilla-La
Mancha, Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain
*Corresponding author: [email protected]
In this work, the scale up of the flushing-fluid-assisted electrokinetic remediation of
kaolin soil polluted with phenanthrene was studied. Three different scales ranging from
lab to pilot scale plants were used to compare the significance of the different
mechanisms of removal of pollutant and to point out the significance of the scaling
factors on the results obtained in electrochemically assisted remediation studies. Figure
1 shows an scheme of the three electrokinetic remediation plants used in this work.
Figure 1. Experimental setups of electrorremediation processes: lab scale (25 cm3), bench scale
(28 x103 cm3) and pilot scale (175 x103 cm3).
Results show that electrokinetic fluxes, removals of PHE and pollutant distribution in
soil were very different in the three setups in spite of being the same soil, pollutant and
operation conditions. Electroosmotic fluxes were much bigger in the case of the lab
scale setup and very similar in the bench scale plant and in the pilot mock up, just as
expected according to the PHE fluxes and to the distribution of PHE removal.
Moreover, in the pilot scale plant used, hydraulic flux produced by gravity and
evaporation flux by electric heating of the soil should be taken considered. This variety
of results suggests a very complex process with many factors influencing on results [1].
In the lab scale plant, the main mechanisms involved in the removal of PHE are
Anodic well Surfactant wellCathodic well
Pilot Scale
Bench Scale
Lab scale
25
cm
50
cm
68
cm
48 cm
16 cm8 cm30 cm
45 cm
25
cm
10 cm
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
168
dragging with electro-osmotic flow in the cathodic wells and electrophoresis after
interaction of surfactant with phenanthrene in the anodic wells. Just on the contrary,
desorption of PHE promoted by the electric heating seems to be a very significant
removal mechanism in the bench scale plant and in the pilot mock-up. Figure 2 shows
the comparison of the removals of PHE obtained in the three setups.
Figure 2. PHE balance in the electroremediation of a clay soil polluted with phenanthrene in lab (), bench () and pilot (▲) scale mock-up. Operation condition: Ez = 1 VDC/cm, initial
pollution: 500 mg PHE kg-1 of soil.
Acknowledgements
Financial support from the Spanish government through project CTM2013-45612-R
and Innocampus (Procesos de electrorremediación, biorremediación y
electrobiorremediación de suelos contaminados) is gratefully acknowledged.
References
[1] R. Lopez-Vizcaino, J. Alonso, P Cañizares, M.J. Leon, V. Navarro, M.A.
Rodrigo, C. Saez, Journal of Hazardous Materials 265 (2014) 142.
0
10
20
30
40
50
60
70
80
90
100
remaining in soil
after treatment
removed in the
anodic well
removed in the
cathodic well
removed by
desorption
mechanism of removal
PH
E (
% P
HE
0)
0.01
0.1
1
10
100
removed in the
anodic well
removed in the
cathodic well
removed by
desorption
mechanism of removalP
HE
(%
PH
E0)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
169
Nº REF.: P311
Electrokinetic treatment of polluted soil by gasoline at pilot level couple with an advanced oxidation process of residual water
L. Ramos-Huerta, A. Garibay-Cordero, B. Ochoa-Méndez, M. Pérez-Corona, J.
Cárdenas-Mijangos and E. Bustosa,*
aParque Tecnológico Querétaro s/n, San Fandila, Pedro Escobedo, Querétaro, México.
C.P. 76730.
Productive activities in Mexico such as mining, extraction and refining of oil, have
caused serious environmental problems. Among them, the generation of large amounts
of waste and hazardous waste, which represents a risk to health and ecosystems. The
remediation of soils contaminated with hydrocarbons using the technique called electro-
remediation (ER) has shown good results at level laboratory and field 1.On the other
hand it is necessary to consider the treatment of wastewater with the contaminant due
electrolyte extracted contains contaminants that were dragged mainly by electroosmosis
process, in consequence it is necessary to implement some treatment of wastewater, as
Fenton treatment which is an advanced oxidation process (AOP) by the hydroxyl
radicals close to anodes 2.
The pilot system consisted of contaminate 3.3 m3 of soil type basalt of the State of
Queretaro to a concentration of 1126 ppm by gasoline, value that is for over the
permissible limits of the mexican law NOM-138-SEMARNAT/SS-2003.
The hydrate soil was added 60L of 6.7x10-4
M NaOH, which was extracted daily after
applying the treatment ER consisted in applying a potential of 20 V for 4.5 hours by a
period of 20 days, across this time the soil treated by ER was characterized. Figure 1
shows the circle arrangement of electrodes with six IrO2-Ta2O5│Ti as anodes around
the central titanium cathode.
Figure 1.-Picture of pilot system with 3.3 m3 with an arrangement of six IrO2-Ta2O5│ Ti anodes
and a central titanium cathode.
The quantification of fats and oils (F&O), was done for the method Soxhlet following
the NMX-AA-005-SCFI-2000, the extract obtained by Soxhlet was dissolves using
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
170
CH2Cl2 and was semi-quantitatively analyzed by Gas Chromatography-Mass
Spectrometry (GC-MS).
In the case of the treatment of polluted water 50% H2SO4, 40% FeSO4, 30% H2O2 and
50% NaOH were used for the Fenton oxidation system. Chemical oxidation demand
(COD), pH and electrical conductivity of the solution were evaluated during Fenton
reaction.
Figure 2 shows presents the results obtained for COD of the extracted solution after
applying electrochemical treatment, which decreased from 50% in the first week to 67%
in the second week. This behavior indicates that organic pollutants were destroyed after
two weeks by ER treatment with electroosmosis process using Fenton treatment.
Finally, with the best quality of treated water after the Fenton reaction, this was re-used
in the ER treatment of polluted soil by gasoline to continue the electroremediation.
Figure 2. Graphical of behavior of COD evaluated during two weeks of ER treatment.
The electroremediation of polluted soils from Mexico is an alternative technology for
cleaning up contaminated soils generated by the oil industry, as well as coupling of an
advanced oxidation process as Fenton reaction for the treatment of polluted solution by
gasoline. This coupling is interesting by the integral process of treatment of polluted
soil and water, which is a competitive advantage with respect to biological systems
widely used in the country.
References
[1] M.P. Corona, E. Beltrán, Sustentable Environmental Research. 2013, 285 –
288. ISSN: 1022-7630.
[2] R. Méndez, J. Pietrogiovanna, Rev. Int. Contam. Ambien. 26 (2010), 211– 220.
276
89
140
48
1 2
CO
D (
mg/
L)
Week
Initial End
Poster Session: Other uses. Miscellaneous.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
173
Nº REF.: P418
Effects of porous properties of carbon felt electrodes on the performance of all-vanadium redox flow batteries (VRFBs)
Seongyeon Won, Kyeongmin Oh, Hyunchul Ju*
Department of Mechanical Engineering, Inha University, 100 Inharo, Namgu, Incheon
402-751, Republic of Korea
The porous structure of electrodes of all-vanadium redox flow batteries (VRFBs) has a
substantial influence on transport characteristics and cell performance during VRFB
charging and discharging processes. A carbon felt has been recognized as the favored
porous-electrode substrate for VRFBs due to several advanced features over other
electrode materials such as low cost and high permeability of liquid electrolyte [1,2].
Desired porous structure and properties of carbon-felt electrodes can be achieved via
optimizing assembly clamping pressure. Chang et al. [3] experimentally showed that as
the clamping pressure increases, the thickness and porosity of the carbon felt electrode
(F1-75P4) decrease whereas its electronic conductivity is improved (see Table 1), which
significantly affects electrolyte and electron transport through the electrodes.
Table 1. Properties of carbon felt electrode under various levels of compression
Carbon felt electrode : F1-75P4
Percentage of
compressions (%) Change on
thickness Compression
(Mpa) Conductivity
(S/m) Porosity
(%) 0 4 →4.0mm 0 31.4 89.5 10 4 →3.6mm 0.139 53.9 88.1 40 4 →2.4mm 0.336 281.2 84.3
In this study, we numerically investigate the effects of porous properties of carbon felt
electrodes on the operation of VRFBs, using a three-dimensional (3-D), transient VRFB
model developed in the previous study [4]. Based on the empirical data of Chang et al.
[3], we precisely account for the relation between the electronic conductivity, porosity,
and thickness of the electrode as a function of electrode compression level. In addition,
the correlation of electronic contact resistance between the porous electrode and current
collector is newly developed as a function of electrode porosity. The modified model is
then applied to a simple VRFB geometry shown in Fig. 1a and charging and discharging
simulations are carried out under different levels of electrode compression. The
calculated cell voltage and state of charge (SOC) evolution curves are presented in Fig.
1b wherein different charging and discharging performances were predicted due mainly
to different degrees of electronic and ionic charge transport losses through the
electrodes. The present study contributes to identifying the optimal design and
compression of carbon felt electrode in VRFBs.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
174
(a)
(b)
Figure 1. (a) Computational domain and mesh configuration of a simple VRFB geometry. and (b) cell voltage and SOC evolution curves under different levels of electrode
compression.
References
[1] A. Di Blasi, O. Di Blasi, N. Briguglio, A.S. Arico, D. Sebastian, M.J. Lazaro, G.
Monforte, V. Antonucci, J. Power Sources, 227 (2013) 15-23
[2] Se-Kook Park, Joonmok Shim, Jung Hoon Yang, Chang-Soo Jin, Bum Suk Lee,
Young-Seak Lee, Kyoung-Hee Shin, Jae-Deok Jeon, Electrochimica Acta, 116
(2014) 447-452
[3] Tien-Chan Chang, Jun-Pu Zhang, Yiin-Kuen Fuh, J. Power Sources, 245 (2014)
66-75
[4] K.Oh, H. Yoo, J, Ko, S, Won, H. Ju, Energy, accepted.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
175
Nº REF.: P419
The effects of hybrid catalyst layer design on methanol and water transport in a direct methanol fuel cell (DMFC)
Kise Lee, Saad Ferekh, Hyunchul Ju*
School of Mechanical Engineering, Inha University,100, Inha-ro, Nam-gu, Incheon
402-752, Republic of Korea
According to the capillary transport theory in porous materials, the rate of liquid
transport can be effectively controlled by the spatial wettability variation of porous
electrode [1-4]. Therefore, in the research field of direct methanol fuel cell (DMFCs),
many researchers have focused on multi-layered electrode designs, using additional
hydrophobic layers [5-8] and/or PTFE-treated anode backing layers (BLs) [9-11], which
successfully reduced methanol crossover and/or water flooding inside a DMFC. In this
study, we propose new catalyst layer (CL) designs based on double-layered structure;
one is coated on the backing layer side whereas the other is on the membrane side.
These two CLs are designed to exhibit different wetting characteristics. The hydrophilic
CL can be fabricated with conventional Nafion binder whereas both Nafion and PTFE
binders are used to design relatively hydrophobic CL. Combining two layers for the
anode or cathode CL enables to effectively control methanol transport in the anode side,
water transport in the cathode, water and methanol crossover through the membrane. To
examine its influence, four different membrane electrode assemblies (MEAs) with
different combinations of anode and cathode CLs are fabricated and tested under
different methanol feed concentrations. Fig. 1 schematically depicts the four MEA
designs, namely MEA-1, MEA-2, MEA-3, and MEA-4.
Figure1. The schematic diagram of four MEA designs with different anode and cathode CLs.
A comparison of polarization curves in Fig. 2 clearly demonstrates a substantial
influence of double-layered CL structure on methanol and water transport, and resultant
overall cell performance. In addition to the experimental observation, a one-dimensional
hybrid CL model is newly developed and simulated in order to theoretically analyze
methanol and water transport characteristics through the double-layered (hydrophobic +
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
176
hydrophilic) CL structures. This study emphasizes that controlling wetting
characteristics of CLs is effective to obtain favorable methanol and water profiles inside
a DMFC.
Figure 2. Polarization curves of MEAs measured at different methanol-feed concentrations (3M,
4M). The cell was operated at 60℃ and an anode/cathode stoichiometry of 3/3 at 200mA/cm².
References
[1] H.C. Ju, J. Power Sources. 185 (2008) 55
[2] K.M. Kang, K.M. Oh, S.H. Park, A.R. Jo, H.C. Ju, J. Power Sources. 212 (2012)
93
[3] A. Pablo, G. Salaberri, M. Vera, I. Iglesias, J. Power Sources. 246 (2014) 239
[4] C.E. Shaffer, C.Y. Wang, Electrochimica Acta. 54 (2009) 5761
[5] K.M. Kang, G.Y. Lee, G.H. Gwak, Y.J. Choi, H.C. Ju, Int. J. Hydrogen Energy.
37 (2012) 6285
[6] Y.C. Park, D.H. Kim, S.Y. Lim, S.K. Kim, D.H. Peck, D.H. Jung, Int. J.
Hydrogen Energy. 37 (2012) 4717
[7] C.G. Suo, X.W. Liu, X.C. Tang, Y.F. Zhang, B. Zhang, P. Zhang,
Electrochemistry commun. 10 (2008) 1606
[8] J.Y. Cao, M. Chen, J. Chen, S.J. Wang, Z.Q. Zou, Z.L. Lin, D. L. Akins, H. Yang,
Int. J. Hydrogen Energy. 35 (2010) 4622
[9] C. Xu, T.S. Zhao, Q. Ye, Electrochim. Acta. 51 (2006) 5524
[10] K.M. Kang, S.H. Park, G.H. Gwak, A.R. Jo, M.S. Kim, Y.D. Lim, W.H. Kim,
T.W. Hong, D.M. Kim, H.C. Ju, Int. J. Hydrogen Energy. 39 (2014) 1564
[11] C.M. Hwang, M. Ishida, H. Ito, T. Maeda, A. Nakano, A. Kato, T. Yoshida, J. Int.
Cou. Electrical Engineering. 2 (2012) 171
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177
Nº REF.: P428
Electrochemical peroxidation using iron nanoparticles to remove arsenic from copper smelter wastewater
Henrik K. Hansena*
, Claudia Gutiérreza, Adrián Rojo
a, Patricio Nuñez
a, Erica
Valdezb
a Departamento de Ingeniería Química y Ambiental, Universidad Técnica Federico
Santa María, Avenida España 1680, Valparaíso, V Region, Chile b Departamento de Química, Universidad Técnica Federico Santa María, Avenida
España 1680, Valparaíso, V Region, Chile
*Corresponding author: [email protected]
Chile is one of the main copper manufacturers in the world. During the processing of
sulfide minerals, the smelter process, gases that contain sulfur dioxide and arsenic
among others are produced: These gases must be cleaned before discharge in the
environment. In the copper smelter gas cleaning process a wastewater is produced and it
contains high concentrations of arsenic and others heavy metals that are far over the
Chilean threshold value for discharge in the aquatic environment. At present the
wastewaters are treated with Ca(OH)2, to increase the pH to approximately a value of
10, which favors the precipitation of heavy metals as hydroxides but also precipitates
calcium sulfate. Large amounts of arsenic remain soluble in the wastewater and the
Ca(OH)2 addition produces a great volume of sludge, owing to the fact that initial pH of
the wastewater is too acid (pH <1.0). This methodology has the disadvantage that great
quantity of sludge is produced and requires a subsequent treatment. There are several
technologies based on the use of ferric oxides and hydroxides (HFO) that are used to
remove heavy metals from wastewaters. This technologies present an alternative to the
treatment with Ca(OH)2, that at the moment is been applied. The HFO are highly
insoluble precipitates (Ksp ≈ 10-38
) with a large surface area (around 600 m2 g
-1). This
precipitates are brown –orange colored and have a high affinity to adsorb several heavy
metals, because of this, are used in wastewaters treatments.
The Electrochemical Peroxidation process (ECP) is one of the methods that use the
HFO to remove heavy metals. Until now this process has used steel electrodes and a DC
electrical current between them to dissolve the anode and provide the Fe+2
that react
with the hydrogen peroxide to produce the Fe+3
that subsequently results in the HFO
production. In this work it is proposed to use inert electrodes such as carbon electrodes
and iron nanoparticle addition to provide the Fe+2
when the Fe0 is oxidized by the anode
process. This could be advantageous over the ECP process when the iron electrodes are
dissolved, because from the operational point of view, an electrode renewal would not
be necessary since the carbon electrodes are not sacrificial.
Iron nanoparticles (NZVI), are highly reactive, they have large surface area and small
particle size, which allow them to remain in suspension. The iron nanoparticles possess
dual properties, because of the dense metallic center enclosed by a thin layer of iron
oxide material (FeOOH). The thickness of the outer layer varies from 10 to 20 nm. The
oxide layer is an inherent part of the nanoparticles formed instantaneously during their
synthesis to passivize the metallic center. The oxide layer allows electron passage,
conserving the reducing properties of Fe0, owing to the fact that the layer is extremely
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
178
thin and disordered. Besides iron oxides formed from Fe0
corrosion are able to oxidize
As (III) to As (V). Therefore iron nanoparticles are able to oxidize and reduce As (III).
This work proposes the HFO formation through the ECP process by the iron
nanoparticles oxidation at the anode and later the oxidation of ferrous ions to ferric ions
by hydrogen peroxide. The metals removal occurs due to the formation of the HFO
followed by an adsorption and/or co-precipitation.
In the present work a study of the ECP process was made by using carbon electrodes
and iron nanoparticles. The arsenic removals from synthetic and real wastewaters from
copper pyro metallurgical industry were evaluated. The experiments were carried out in
a batch reactor at laboratory scale, of 2 L of volume, with agitation by air injection; the
airflow was approximately 5 L min-1
. A fixed current density of 171.7 A m-2
was used
and a dosage of hydrogen peroxide 30 % w/w was supplied to the solution drop wise to
around 0.5 - 1 mL min-1
. The parameters analyzed were the initial pH of the wastewater,
that was in the range of 2.0 to 6.5 and the treatment time, that was done from 30 to 180
min. The results when the ECP process, with carbon electrodes and iron nanoparticles
was applied for 1 h, in the pH range of 2.0 to 6.5, to treat As (III) synthetic wastewater,
showed that the As maximum removal was 62.4 % at a pH of 6.5; being approximately
constant when more treatment time was applied. When treating As (V) wastewater, the
maximum removal was 99.7 % at a pH of 5.0. When working with real wastewaters in
the pH range of 3.5 to 6.5; the arsenic maximum removal was 96 % at pH 6.5; this last
removal was approximately constant when more treatment time was applied. The ECP
process showed to be a capable technology to remove high concentrations of arsenic
(1000 to 3000 mg L-1
) when carbon electrodes and iron nanoparticles are used.
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179
Nº REF.: P438
Applying EK to achieve SMART (simultaneous modified assisted recovery techniques) EOR in carbonate reservoirs of Abu Dhabi
Nabeela Al Kindya, Mohamed Haroun
b,*, Arsalan Ansari
c, George V. Chilingar
d,
Hemanta Sarmae
a, b, c, e The Petroleum Institute, Abu Dhabi, P.O. Box: 2533, U.A.E.
d University of Southern California, Los Angeles, CA 90089, USA
*Mohamed Haroun: [email protected]
Among the emerging EOR technologies in carbonate reservoirs are Nano-EOR and
surfactant-EOR in conjunction with the application of Electrically Enhanced Oil
Recovery (EEOR) [2-6]. This is gaining increased attention due to a number of
reservoir-related advantages such as reduction in fluid viscosity, water-cut and
increased reservoir permeability.
The concept of SMART EORtakes advantage of the high transport phenomena of EK
coupled with chemical flooding to enhance depth of penetration[3-6]. The main
objective of this research is to target unswept oil efficiently while reducing HSE
concerns of handling and transporting the nano and surfactant particles. Experiments
were conducted on 1.5-inch. carbonate reservoir core-plugs from Abu Dhabi producing
oilfields with porosity and permeability ranging from 0.01 to 21% and 0.007 to 24.4
mD, respectively. Several nano particles including CuO and NiO of 50nm size range
were tested and compared for ultimate recovery factors against the injection of a non-
ionic alkyl polyglucoside (APG) with C10/12 chain structure, a blend of nonionic-
anionic APG surfactant and a cationic fatty amine based betaine surfactant were
evaluated for this study. These surfactants were selected based on the fact that they are
synthesized from renewable resources such as starch and coco derivatives, easily bio-
degradable and have very low ecotoxicity.
Fig. 1. SMART EOR at ambient conditions. Ansari et al., 2012 [3]
The experimental results at ambient conditions show that the application of
waterflooding on the water-wet carbonate core-plugs yields a recovery of approximately
46-72%, whereas SMARTEOR enhanced the recovery by an additional 7-14%. An
additional 6-11% improvement in recovery was achieved by the application of EK.
Essentially, SMART EOR produced an average of 79-81% displacement efficiency
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
180
from all the carbonate reservoir cores tested at ambient conditions as can be seen in Fig.
1 [Ansari et al., 2012].
The results to Abu Dhabi reservoir conditions (high temperature, pressure and
formation water composition) yielded another 6-10% increase in ultimate recovery.
Overall, SMART EOR produced an average of 85-88% displacement efficiency from all
the carbonate reservoir cores tested at Abu Dhabi reservoir conditions (formation water
composition 270k ppm TDS) 10% increased oil displacement and more than 50%
reduced water injected [Haroun et al., 2013 and 2014] as can be seen in Fig. 2.
Fig. 2 a and b. EEOR vs SMART EOR at ambient conditions (a) vs. elevated reservoir conditions
(b) in carbonate reservoir core-plugs
Furthermore, this process can be engineered to be a sustainable approach as the water
requirement can be reduced by more than 50% on application of electrokinetics, while
power consumption can be optimized at $4/Bbl, thus improving environomics[1].
References
[1] Al Kindy N., Haroun M., Ansari A. and Sarma H., 2013. Application of
Electrokinetics to achieve Smart Nano-Surfactant EOR in Abu Dhabi Carbonate
Reservoirs. ADIPEC.
[2] Amba, S.A., Chilingar, G.V. and Beeson, C.M., 1964. Use of direct electrical
current for increasing the flow rate of reservoir fluids during petroleum recovery.
J. Canad. Petrol. Technol., 3 (1):8-14.
[3] Ansari, A., Haroun, M., Abou Sayed N., Al Kindy, N., Ali, B., Shrestha, R., and
Sarma, H., 2012. A new approach optimizing mature waterfloods with
electrokinetics-assisted surfactant flooding in Abu Dhabi carbonate reservoirs.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
181
SPE 163379 SPE Kuwait International Petroleum Conference and Exhibition,
Kuwait, 10-12 Dec.
[4] Haroun, M., Ansari, A. and Al Kindy, N., 2014. Applying EK to achieve SMART
(simultaneous assisted recovery techniques) EOR in conventional and tight
carbonate reservoirs of Abu Dhabi. Electrochemistry Gordon Research
Conference, Ventura, CA.
[5] Haroun, M., Ansari, A., Al Kindy, N., Abou Sayed, N., Ali, B., Shrestha, R., and
Sarma, H., 2013. Application of electrokinetics to achieve smart EOR in Abu
Dhabi oil-wet carbonate reservoirs. Presented at the Electrokinetic Remediation
Conference, June 23-26.
[6] Haroun M., Wittle J.K. and Chilingar G.V., 2012. Publication No.
WO/2012/074510. Title of the invention: "Method for Enhanced Oil recovery
from Carbonate Reservoirs." Applicants: ELECTRO-PETROLEUM, INC. (US).
Inventors: Mohammed Haroun (AE), J. Kenneth Wittle (US) and George
Chilingar (US), June 12.
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182
Nº REF.: P444
Electrochemical degradation of chlorobenzene in water using Pd- catalytic electro-Fenton’s reaction
Ali Ciblak, RoyaNazari*, Ibrahim Mousa, Akram Alshawabkeh*
Department of Civil and Environmental Engineering, Northeastern University, 400
Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, United States
Presenter: [email protected]
In this study, a three electrode flow system is proposed for Pd-catalytic oxidation of
chlorobenzene (CB) in groundwater. The system is consisted of sequentially arranged
electrodes, one mixed metal oxide (MMO) anode and two MMO cathodes. Applied
current is divided between cathodes to develop acidic vicinity around the first cathode.
Two grams of Pd/Al2O3 is packed at the top of the first cathode to catalyze
electrochemically generation of H2O2. Column experiments are conducted to investigate
the system variables. Their performance for CB removal was evaluated in open flow
column at room temperature. The results indicate that three electrodes system with
supported Pd/Al2O3 on the surface of cathode can be used for the removal of CB
pollution and their capacity does not depend on the nature of the CB concentration.
Also, the three MMO electrodes provide more acidic conditions comparing two
electrode systems for better oxidation. Compared with the dehalogenation with a total
CB removal of 44% in 2 h with Pd/Al2O3, the CB removal reached 56-64% with
Pd/Al2O3 supported with ferrous salts under the same operate condition. With the
proposed treatment, the electrochemical process supported with Pd keep the degradation
of CB for long time without replacement.
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183
Nº REF.: P447
Hydrodechlorination of TCE by Pd and H2 produced from a copper foam cathode in a circulated electrolytic column at high flow rate
Noushin Fallahpoura, SonghuYuan
a,b, Akram N. Alshawabkeh
a,*
aCivil and Environmental Engineering Department, Northeastern University, Boston,
MA, 02115, USA. bState Key Lab of Biogeology and Environmental Geology, China University of
Geosciences, Wuhan, 430074, P. R. China.
*Corresponding author: E-mail: [email protected]
Abstract
Pd-catalytic hydrodechlorination of trichloroethylene (TCE) using cathodicH2in situ
produced from water electrolysis has been reported. For a field in-well application, the
flow rate is generally high. In this study, the performance of Pd-catalytic
hydrodechlorination of TCE using cathodic H2 is evaluated under high flow rate (1
L/min) in a circulated column system. An iron anode and a copper foam cathode are
used to enhance TCE hydrodechlorination because iron anode improves reducing
conditions and copper foam cathode can hydrodechlorinate TCE directly in addition to
H2 production. Under the conditions of 1 L/min flow rate, 500 mA current, and 5 mg/L
initial concentration, TCE removal efficacy using iron anode (96%) is significantly
higher than using mixed metal oxide (MMO) anode (66%). Two sets of experiments
with iron anode and two types of cathodes (MMO and copper foam) in the presence of
Pd/ Al2O3 catalyst under various current intensities were conducted to evaluate the
effect of cathode materials. The removal efficienciesare almost the same for both
cathodes under the same conditions, with more precipitation generated using copper
foam cathode. Packing Pd pellets into a column with iron anode and copper foam
cathode improves the removal rate to 90% for all the currents applied except 62 mA,
with production of less precipitates. For the potential field application, a cost-effective
and sustainable in situelectrochemical process is proposed using asolar panel as power
supply.
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184
Nº REF.: P456
Enhancing electro-Fenton chlorobenzene degradation from groundwater, oxidation technique in the presence of Pd with different catalyst supports
Ibrahim Mousa1*, Akram Alshawabkeh
2
1Department of Environmental biotechnology, Genetic engineering and biotechnology
institute (GEBRI), University of Sadat city, Minoufia 22857, Egypt. 2Department of Civil and Environmental Engineering, Northeastern University, 400
Snell Engineering, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
Presenter email : [email protected]
ABSTRACT
The study of the electrochemical degradation of Chlorobenzene is becoming
increasingly an important issue in environmental electrochemistry. Oxidation of CB
using Pd/A2O3 and Pd/AC as catalysts at mild conditions (20±1 0C, 1 atm) was carried
out in three electrodes column with Na2SO4 and FeSO4 as supporting electrolyte at
different pH. The highest reaction rate was achieved when the process was carried out at
a solution of pH= 3. The Pd/AC showed an appreciable loss of activity upon time on
stream, which was associated with the adsorption capacity. However, a residual activity
remained practically stable, reaching very similar CB conversion (62 and 72%) in
presence of Pd/A2O3 and Pd/AC, respectively. The Pd/AC catalyst maintained a
constant activity at a 72% CB conversion once the steady state was reached. This
suggests that the AC supported catalyst is less susceptible to the chloride poisoning
produced during the reaction with high adsorption capacity.
Background
Chlorobenzenes are intermediates in the industrial production of drugs, scents, dyestuff,
herbicides, and insecticides. They are also used as additives to oils, lubricants, and dye-
carriers, and are employed in heat exchange systems and for dielectric insulation
(Adrian and Gorisch, 2002). Large quantities of chlorobenzenes have been released to
the environment as a consequence of the wide use during the last decades (Lee and
Fang, 1997). Chlorobenzenes are hydrophobic, persistent, and some of them are chronic
to animals and humans (Lee and Fang, 1997). They are typically associated with soils
through hydrophobic bonding (Song-hu et al., 2007).
Table 1 Variation of element composition for Pd/Al2O3and Pd/AC pellets after catalysis process.
Element Pd/Al2O3 Pd/AC
C K 6.16 75.36
O K 35.01 18.92
AlK 56.15
PdL 3.74 2.54
NaK 0.41
K K 3.18
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
185
Fig. Microstructure of Pd/Al2O3 pellets and Pd/AC catalysts with FESEM images and EDAX analysis.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
186
Nº REF.: P457
Feasibility of modeling by adsorption the magnetic separation of iron nanoparticles
Fiona Lancellottia, Francisco Retamal
a, Patricio Núñez
a, Henrik Hansen
a*.
aUniversidad Técnica Federico Santa María, Valparaíso, Chile.
*Corresponding author: [email protected]
High and low magnetic field separation systems considering the competing forces and
the probability of a particle to be captured have been modeled extensively by numerous
authors. Although models have demonstrated accuracy with respect to the experimental
data, their point of view has always been from physicals or electric engineering. This
work proposes the modeling of magnetic separation from the point of view of a well-
known chemical engineering process, the adsorption process.
The modeling consisted in looking a low magnetic separation system for removing iron
nanoparticles as a fixed-bed adsorber where the steel wool inside was considered to be
the porous media where nanoparticles were adsorbed in its surface. The resulting model
was a typical 1D advection-dispersion model with Danckwerts’ boundary conditions.
The model was solved in COMSOL Multiphysics version 4.3 and validated
theoretically and experimentally. Theoretical validation showed high representativeness
using other papers parameters and data. Contrasting the model with experimental data
for two magnetic filters made experimental validation. The magnetic filters were
stainless steel tubes filled with stainless steel wool and rounded by a coil which
produced the magnetic field. The filters were operated as continual systems.
The magnetic separation process of iron nanoparticles could be represented by an
adsorption model, only in early stages of operation, this is, few time after saturation of
the filters. It was found that the greater impact in both model and operation of magnetic
filters were volumetric flow, maximum adsorbent capacity and, principally, inlet
concentration.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
187
Oxidation
1st Precipitation
2nd Precipitation
Filtration
Drying and calcination
Raw wastewater from copper smelter gas cleaningpH: <1As: 4.000 – 15.000 [mg/L]
Oxidized raw wastewaterpH: <1As: 4.000 – 15.000 [mg/L]
Wastewater after 1st PrecipitationpH: ≈1As: 100 – 1.000 [mg/L]
H2O2
Ca(OH)2
Floculant
Fe2(SO4)3/FeCl3
HCl/H2SO4
Floculant
Treated wastewaterpH: ≈7As: 0,1 – 5 [mg/L]
Wet solids
Stabilized solid residue with arsenic and
heavy metals
Sludge
Sludge
CaCO3
Filtrate
Figure 1- Copper smelter gas cleaning wastewater treatment scheme
Nanoparticles tank
Wastewater AirElectrocoagulator
Clarifier
ValvePinch
Timer
Clean water
DC
Clean Water
DC DC
Nanoparticlesto tratament
Nanoparticlesto tratament
Nanoparticles recovery
Arsenic disposal
Figure 2 - Pilot plant proposal for arsenic removal with iron nanoparticles.
The filters achieved high filtration efficiencies, being 99,8% and 98,5% the lowest
values for the bigger and smaller filters, respectively. The maximum retention capacity
for bigger filter was 1,52 [g iron nanoparticles/ g steel wool] under 0,07 [T] and for
smaller filter, 1,23 [g iron nanoparticles/ g steel wool] under 0,08 [T]. The optimum
operation times until saturation for bigger and smaller filters were round 20 [min] and 8
[min], respectively. After these times, the increment in coil temperature could be
affecting the retention capacity of the filter. It was observed that highest utilization
capacity for both filters (near to 95,5%) were obtained with highest inlet concentration.
The higher equivalent mass retained gave the higher utilization capacity. For similar
utilization capacity (≈95%), a smaller volume filter produced a bigger utilization of the
adsorbent because the space velocity was bigger. Figure 3 shows the actual filtration
efficiency at different flow rates.
Figure 3. Iron Nano particle filtration Efficiency
The following equation was used to model the process of magnetic filter, assuming that
is analogous to an adsorption process.
(
) |
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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The results of this equation is plotted on Figure 4,that shows a good agreement among
the data points and the model prediction.
Figure 5 - Experimental setup of the smaller magnetic filtration system
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº REF.: P458
Electrocoagulation reactor design for arsenic treatment
Diego Pinedaa, Patricio Núñez
a, Henrik Hansen
a*.
aUniversidad Técnica Federico Santa María, Valparaíso, Chile.
*Corresponding author: [email protected]
Chile is the main producer of copper in the world with 32,7% of the world production in
the 2010, by the 2012 there were produced 5.455.000[ton] of this mineral. Most of the
industrial wastewater generated in the mineral processing carries heavy metals and
sulfates in high concentrations, which ones are highly polluting. Based on the
electrocoagulation process, developed by the research team, see Figure 1, for the
treatment of arsenic from waste water, a procedure for the design of a continuous
electrocoagulation reactor was developed: a set of batch experience, using this data a
kinetic model was proposed and the kinetic parameters determined; then a continuous
electrocoagulation reactor was design and built, to test the scale up procedure.
The batch reactor was built as two concentric graphite cylinders, that are operated as an
air lift reactor, using air that is supply to the inner cylinder. The continuous
electrocoagulation reactor has three concentric cylinders units that are set up inside a
larger tank. Previously the use of iron nanoparticles for the arsenic removal and other
heavy metals has been study, as well as the electrocoagulation, but there is no
mechanism, stoichiometry or kinetic model to represent them. The contribution and
innovation of this research is the combination of both technics, his potentials and
advantages and bring them to bigger scales and arsenic concentration, besides the own
design of the reactor and its way of operation (Figure 1)
In this research 11 batch experiments were done, obtaining efficiencies of arsenic
removal over 98% at 45[min] of reaction time. Then 6 continuous experiments were
done, obtaining efficiencies over 90% of arsenic removal at 30[min] of residence time
by adding mechanical stirring.
A kinetic model was propose to fit the batch data and based on this model a continuous
reactor was design, Figure 2 shows the actual reactor. Figure 3 shows the results for the
Arsenic removal for the batch reactor.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Figure 1 – Process flow Diagram Arsenic Treatment (Liquid Industrial Wastewater)
Figure 2 – General overview of the reactor
Figure 3 – Results of Arsenic Remotion (Batch Experiment)
The analysis of the experiment data and the model that was developed shows that:
1. The kinetics determination of the electrocoagulation of arsenic using iron nano
particles on a batch reactor should be used as the basic data for the scale up of a
continuous reactor.
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2. The continuous reactor operation shows that a set of three units of basic
electrocoagulation reactor and a mechanical stirred is a set up that allows for a
good mixing and maintenance of the electrocoagulation units.
3. The removal of the arsenic on the waste water is similar for the batch reactor at
the same current density 38 (A/m2), 95% (batch) and 90%(continuous)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº REF.: P463
Desalination of sandstone with two different setups under an applied electric field
Ondřej Matyščáka, Jorge Feijoo Condeb
*, Lisbeth M. Ottosen
c
aDepartment of Civil Engineering, Brno University of Technology, 602 00 Brno, Czech
Republic bDept. of Natural resources and environmental. University of Vigo Campus Lagoas,
36310 Vigo-Spain cDepartment of Civil Engineering, Technical University of Denmark, 2800 Kgs. Lyngby,
Denmark
Soluble salts are considered as one of the main degradation agents which can affect the
architectural heritage [1, 2]. There are currently many different techniques that try to
decrease the salt concentration to the levels meeting safety limits. At the present time,
the technique called electrokinetics is the most highlighted. The efficiency and the
suitability of this technique have been demonstrated in several studies both in the
laboratory [3-5] and in the pilot scale test [6]. The present study aims to compare the
removal efficiency of chlorides from a sandstone when two different electrokinetic
setups are used.
The laboratory experiment was conducted with a big block of sandstone of 0.02 m3
which was contaminated with unknown amount of chlorides. The main goal of this
investigation was to analyse the removal efficiency of chlorides in the areas where the
electrode units were placed. In the first electrokinetic setup, 6 plastic cylinders
(electrode units) of 0.03 m2 filled with the clay poultices were placed oppositely at
different heights of the sandstone block (upper, middle and bottom placement). The
placement of the cylinders covered about 5.6 % of the total rock surface. The second
electrokinetic setup consisted of two casings (electrode units) filled with clay poultices
were placed oppositely as well. The covering with casings was about 9.3 % of the total
rock surface. The results obtained from these two different setups were compared.
It was shown that the bigger surface area covered with the electrode units, the bigger
influence on desalination efficiency it had. Therefore it was found out that the second
electrokinetic setup showed higher removal efficiency for chlorides from the sandstone.
It was also shown that the distance between the electrode units was a limiting factor of
this technique.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
193
Figure 1.: average mass of chloride (2 test per setup) extracted by the poultices applied close to
the electrodes at different heights
References
[1] Charola, A.E. Salts in the deterioration of porous materials: an overview. Journal
of America Institute of Conservation 39 (2000) 327-343.
[2] Doehne, E. Salt weathering: a selective review. Segesmund S., Weiss T. and
Vollbrecht A. Natural stone weathering phenomena, conservation strategies and
case studies. Geological Society. London. Special publications, 205, 51-64
(2002).
[3] Ottosen, L.M.; Christensen, I. (2012) Electrokinetic desalination of sandstones for
NaCl removal – Test of different clay poultices at the electrodes. Electrochimica
Acta
[4] Feijoo. J.; Nóvoa. X.R.; Rivas. T.; Mosquera. M.J.; Taboada. J.; Montojo. C.;
Carrera. F. (2012).- “Granite desalination using electromigration. Influence of
type of granite and saline contaminant”. Journal of Cultural Heritage.
[5] Rörig-Dalgaard. I.; Ottosen. L.M.; Hansen. K.K. (2012).- “Diffusion and
electromigration in clay bricks influenced by differences in the pore system
resulting from firing”. Construction and Building Materials 27 390-397
[6] Ottosen. L.M.; Rörig-Dalgaard. I.; Villumsen. A. (2008).- “Electrochemical
removal of salts from masonry- experiences from pilot scale”
Acknowledgements
J. Feijoo research was funded by a FPU-predoctoral grant by the Ministerio de
Educación of Spain.
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Nº REF.: P472
Evaluation of microbial communities, growth rates and susbtrate consumption under electrical field
M. Zeyoudi and S.W. Hasan*
Institute Center for Water and Environment (iWATER), Chemical and Environmental
Engineering Department, Masdar Institute of Science and Technology, Abu Dhabi,
United Arab Emirates, PO Box 54224
*Corresponding author: e-mail address: [email protected]
The application of electro-technologies in the UAE existing biological treatment
methods requires further understanding of the behavior of the microorganisms
(biodegraders) to improve the quality of the treated effluent. Therefore, the primary
objective of this research study was to evaluate the microbial communities present in
bio-electrochemical reactor under different operating conditions such as current density
and exposure time to electricity to achieve system process stability. This study was
divided into two Phases. In Phase 1, a laboratory scale study was conducted at different
current density ranging between 5 and 20 A/m2
continuously supplied with no addition
of substrate. Phase 2 evaluated the bacteria count, substrate utilization rate (organic
removal), and microbial process biokinetics (bacteria growth rate and doubling time) at
continuous supply of electric field at different current density (Stage 1), and at
intermittent supply of electric field at constant current density of 15 A/m2 (Stage 2). The
results from Phase 1 revealed that the continuous supply of electric field had significant
stimulation effect on microorganisms at low current density of 5 A/m2 (bacteria count
has increased from 80,000 (initially) to 1,686,600 CFU/mL after 12 h) when compared
to the bacteria count at high current density of 20 A/m2
(bacteria count has increased
from 80,000 (initially) to 263,600 CFU/mL after 12 h). Moreover, in Phase 2 – Stage 1,
the bacteria count in the bioreactors has increased from 200,000 CFU/mL (initially) to
540,000, 920,000, 1,460,000 and 320,000 CFU/mL at 15, 10, 5, and 0 (control) A/m2,
respectively. However, the growth rate of living microorganisms at intermittent supply
(Phase 2 – Stage 2) of electricity at 15 A/m2 was also higher (0.1 1/h) when compared
to the control reactor through which no electric field was supplied (0.08 1/h). A similar
observation was reported with respect to substrate removal as the concentration of
sCOD was 35, 25, 25, 24, and 54 mg/L at 5 min ON yet with 10, 15, 20, 30 min OFF,
and Control, respectively. The success of this study would contribute to the
implementation of electro-technologies in the wastewater treatment plants in the UAE.
References
[1] M. Zeyoudi. , Microbial process biokinetics under DC electrical field for bio-
electrochemical wastewater treatment related applications, M.Sc. thesis, Masdar
Institute of Science and Technology, Abu Dhabi - UAE (2014)
[2] V. Wei, M. Elektorowicz, and J.A. Oleszkiewicz, Influence of electric current on
bacterial viability in wastewater treatment. Water res. 45 (2011) 5058-5062
Poster Session: Organic and chlorinated organic compounds remediation
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
197
Nº REF.: P507
Electrokinetic-Fenton process for remediation of PAHs-contaminated railroad soil
Woo-Sung Junga,*
, Jae-Young Leea, Young-Min Cho
a and Ji-Won Yang
b
aKorea Railroad Research Institute, Uiwang-si, 437-757, Republic of Korea
bKorea Advanced Institute of Science and Technology, Daejeon-city, 305-701, Republic
of Korea
*Corresponding author: [email protected]
1. Introduction
Because the railroad yard and soil-contaminating facilities are scattered over broad area,
it’s difficult in identifying the soil contamination status as well as monitoring and
controlling the soil contamination source. Soil contamination at railroad site is mostly
around refueling facilities where the soil is contaminated by spilled, leaked or dropped
oil and at station area, heavy oil such as grease or lubricant leaked during the train stops
for extended time causes the contamination which takes more time and cost in restoring
than the area contaminated by diesel. This study, to purify the railroad oil-contaminated
soil, is intended to determine the activity parameter to enhance the applicability and
processing efficiency as well as identify the optimal processing efficiency by applying
such complex technique as Electrokinetic-Fenton process, thereby identifying the
applicability to soil-contaminated railroad yard.
2. Experiment
Electro-kinetic reactor was fabricated with 4cm-diameter and 20cm-long glass
cylindrical tube and tested at constant-current condition of 5~10mA(0.4~0.8 mA/cm2)
and 75 mL electrode device was attached to both ends of reactor and the tube to
discharge the gas generated by electrolysis was placed on top. Graphite plate was used
for electrode and the voltage could be raised up to 200V using DC supply device.
Kaolinite was used as soil specimen which was dried and crushed to the grain sized less
than 150 μm passing through No. 100 sieve. Clay was used as contamination medium
and PAHs (aromatic hydrocarbon) which is the oil component was determined the
model contaminant. Phenanthrene-contaminated soil was made by mixing
phenanthrene-acetone solution with soil and evaporating acetone. Initial soil
contamination concentration was set as 600~700 mg/kg dry soil and during the test,
variation in soil voltage and electric osmotic quantity were measured. After finishing
the test (Table 1) soil specimen was cut into the piece in certain length and dried before
analyzing the concentration of phenanthrene remained in soil.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Table 1. Experimental condition of electrokinetic-fenton process tests
No. Current (mA) Concentration (%) Period (week) Electrode change (time)
1
5 3.5
1
None 2 2
3 3
4
10 3.5
1
None 5 2
6 3
7 4
8 10 10 2 None
9 10
3.5 4 1 10
Figure 1. Schematic diagram of electrokinetic-fenton process
3. Result & Discussions
As a result, maximum efficiency was 80.5% as shown in Table 2. However, the size of
soil grain was 150 μm or less, the removal efficiency would possibly be increased to
90% in soil with greater permeability. The longer the process period the higher the
efficiency and the pollutant in cathode, besides anode, could be eliminated by replacing
the electrode.
Table 2. Result of electrokinetic-fenton process tests
Test No Current
(㎃)
Concentration
(%)
Electro
exchange
(time )
Process
period
(week)
Total EOF
(ml)
Removal
rate (%)
1
5 3.5 None
1 495 15.1
2 2 811 29.9
3 3 1262 32.2
4
10 3.5 None
1 1033 21.8
5 2 1582 40.6
6 3 2115 55.9
7 4 2354 61.4
8 10 10 None 2 1348 51.2
9 10 3.5 1 4 2405 80.5
H2 gas venting
Voltagemeter
Power supply
Anode(+) Cathode(-)
O2 gas venting
Soil(clay)
Cathode
tank
Soil (clay)
Anode
tank
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As indicated in Fig. 2(a) and (b), as the process time was extended in 5 mA and 10 mA,
removal rate was accordingly increased and movement of hydrogen peroxide was
getting faster in line with increased electro—osmosis at higher current. Thus very few
cathode was removed at 5 mA which was however increased even at cathode at 10 mA.
Fig. 2(c) compares a 2-week test result with hydrogen peroxide 3.5% and 10%,
respectively and no significant difference was indicated. (Exp. no. 5, 8). Such result
proved that dissolution speed as constraint and increase in concentration of hydrogen
peroxide had insignificant effect on removal rate. As a result of electrokinetic-Fenton
test, in removing the pollutant, smooth flow of hydrogen peroxide and stability are the
critical factor and supply location & concentration of hydrogen peroxide, induced
current and process period had a significant effect on pollutant removal rate. In addition,
replacing the electrode also significantly increased the pollutant removal rate in cathode.
(a) Experimental No. 1-3 (b) Experimental No. 4-8 (c) Experimental No. 5, 7, 8, 9
Figure 2. Result of electrokinetic-fenton process tests
Acknowledgements
This work was financially supported by R&D program through the basic research of
Korea by the Ministry of Science, ICT & Future Planning (grant number PK14003B).
References
[1] Manachan, S.E., Environment Chemistry, Willard Grant Press, Boston(2009).
[2] Albert T. Yeung, Contaminate Extractability by Electrokinetics, Enviro. Eng.
Science 23 (2006).
[3] EPA., Subsurface Characterization and Monitering Techniques: Vol II(2008)
[4] Michael J. H., The use of electrokintics to enhance the degradation of organic
contaminants in soils(20103)
[5] Jurate Virkutyte, Mica Sillanpaa, Electrokinetic Soil Remediation-critical
Overview, the Science of the Total Enviro. 289(2012)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
200
Nº REF.: P515
Characterization and regeneration of Pd/Al2O3 catalyst along a three electrodes column for chlorobenzene remediation.
Ibrahim E, Mousa1, Ali Ciblak
2, Roya Nazari
2 and Akram N. Alshawabkeh
2*
1 Department of Environmental biotechnology, Genetic engineering and biotechnology
institute (GEBRI), University of Sadat city, Minoufia 22857, Egypt. 2 Department of Civil and Environmental Engineering, Northeastern University, 400
Snell Engineering, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
Abstract
Advanced oxidation processes are reported as promising methods for the remediation of
groundwater contaminated with chlorinated compounds. In our previous study, the
effectiveness of Pd/Al2O3 catalyzed electro-fenton method, an advanced oxidation
process, is investigated in a three-electrodes column for the remediation of
chlorobenzene (CB). Three inert electrodes, one MMO anode and two MMO cathodes
are placed sequentially in the column to generate acidic vicinity for fenton’s reaction.
Pd/Al2O3 particles are packed on the first cathode to enhance H2O2 production needed
to facilitate CB oxidation. In this study, long term catalytic efficiency of palladium
particles is evaluated. After 200 hours of electrolysis, Pd/Al2O3 was regenerated through
reduction by 2% hydrazine. Both new, used and regenerated catalysts were
characterized by field emission scanning electron microscopy (FESEM) equipped with
energy dispersion spectroscopy. The profile of metals and surface texture for both used
and regenerated catalyst was determined. The catalytic activity of regenerated, Pd/Al2O3
was evaluated in the three-electrodes column under different conditions and compared
with new one. The results showed that iron depositions increase and aluminum metal
decreases in used comparing to new catalyst. It was found that both new and used had
same ratio of Pd. A tendency of absence of chloride in used and regenerated catalyst
was observed. Regeneration of Pd/Al2O3 increase CB removal by 40%. Results show
that enhancement of Pd catalyst activity through the regeneration of catalysts is noticed.
Fig. Microstructure of Pd/Al2O3 pellets before and after catalysis processes with FESEM images (10K X).
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
201
Table 1 Variation of element composition for fresh and spent Pd/Al2O3 pellets after catalysis process.
Fresh pellets Spent pellets
Element Point #1 Point #2 Point #3 Point #4 average Point #1 Point #2 Point #3 Point #4 average
C K 5.09 6.4 6.66 6.48 6.16 16.55 25.18 18.08 19.54 19.84
O K 35.51 35.08 32.59 36.84 35.01 32.48 35.77 39.3 33.28 35.21
AlK 56.19 54.07 56.9 57.44 56.15 39.05 31.50 36.7 39.25 36.63
PdL 3.22 4.46 3.41 3.85 3.74 3.87 3.55 3.11 3.45 3.50
S K
0.58 0.42 0.52 0.64 0.54
FeK
7.45 3.34 2.04 3.84 4.17
NaK
0.44 0.38 0.41
0.23 0.24
0.24
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202
Nº REF.: P535
Removal of a thiazine, an azo and a triarylmethane dyes from dyes polluted kaolinite by electrokinetic remediation
Effendia,b
, Shunitz Tanaka a,*
a Graduate School of Environmental Science, Hokkaido University, Sapporo Hokkaido,
060-0810, Japan b Department of Chemistry, Faculty of Mathematics and Natural Science, State
University of Padang, Padang, West Sumatera ,25131, Indonesia
*Corresponding author: [email protected]
Dyes, even in low concentration are visually detected and affect the aquatic life and
food cycle. Methylene Blue (MB) is one of the most commonly used substances for
dyeing cotton, wood, and silk. MB can have various harmful effects such as breathing,
vomiting, several headache, diarrhea, painful micturation and methemoglobinea [1].
Methyl Orange (MO) also use as an pH indicator. The reductive cleavage of the azo
linkage to produce aromatic amines and can even lead to intestinal cancer .High content
in living systems can prove to be harmful.While Phenol Red (PR) inhibits the growth of
renal epithelial cells. Direct/indirect contact, leads to irritation to the eyes, respiratory
system and skin. And also toxic to muscle fibres and has mutagenic effects [2].The
molecular structure of dyes shown in Figure 1.
Figure 1. Molecular Structure of dyes. a) Methylene Blue, b) Methyl Orange and c). Phenol Red
Several methods can be used to remove dye from soil such as biological, physical and
chemical processes. However, the application of electrokinetic remediation is very
promising for soil decontamination polluted by heavy metal [2], and organic
compounds such as Reactive Black 5 (RB5) [3]and Lissamine Green B (LGB) [4] dyes.
Previous rsearch repoted about the removal of dye by several technique [5-8]. This
study proposed the removal of dyes by the electrokinetic remediation by finding the
optimm conditions such as electrolyte , pH,and extractan to obtain the higher percentage
in dye removal.
Materials and Methods
Kaolinite sample preparation
150 g of kaolinite clay mix with 55.5 ml of 0.3 gL-1 dye solution. The mixture stood for
24 h and load to EKR chamber. EKR set up (Fig 2) associate with graphite electrode
and certain electrolyte. A DC Current 30 V and 10 mA use as an electric resources. The
monitoring voltage drop and current density were taken periodically by data logger.
And process will running during 7 to 15 days. After the process was finished, the
a
a b
a
c
a
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
203
sampes were taken from equipment setup and divided by five sections, named S1- S5
from anode to chatode. Measuring the pH by adding potassium chloride 1M solution to
dry kaolinite in certain ratio by using pH meter. Contaminant was extracted with
benzoic acid in water, benzoic acid in xylene and potassium chloride in ethanol
respectively. Finally, the contaminant concentration was determined by absorbance
measurements using UV-Visible spectrophotometer at the maximum wavelength of
dyes means at 665 nm for MB, 440 nm for MO and 560 nm for PR. The result shown
on the Table 1.
Figure 2. Schematic diagram of modified equipment of EKR Cell
Table 1. Percentage Removal of Dyes by kinds of fluid processing after EKR Process
Dye By H2O (%) By Na2SO4 (%) By NaH2PO4 (%)
Methylene Blue 56 75 84
Methyl Orange 72 78 90
Phenol Red 79 82 92
Conclusion
Distribution of pH and concentration for five sections in kaolinite sample from anode to
cathode after EKR is different for any electrolytes. The characterization and behavior
of EKR system was different among all dyes since the difference the structure and the
charge of the dyes
References
[1] G.Muthuraman, Tjoon Tow Teng, Cheu Peng Leh, I.Norli, Journal of Hazardous
Materials, 163 (2009) 363-369.
[2] R.S. Putra, S. Tanaka, Separation and Purification Technology, 79 (2011) 208-
215.
[3] M.Pazos, M.T.Ricart, M.A.Sanroman, C.Cameselle, Electrochemica Acta 52
(2007) 3393-3398.
[4] M.Pazos, C.Cameselle, M.A.Sanroman, Environmental Engineering Science, 25
(2008) 419-426.
[5] A.A.Amina,S.B.Girgis,A.N.Fathy, Dyes Pigment 76 (2008) 282-289.
[6] D.Kavitha,C.Namasivayam, Biresour.Technol, 98 (2007) 14-21.
[7] S.Lakshmi,R.Renganathan,S.Fujita, J.Photo Chem.Photobiol.A.Chem 88 (1995)
163-167.
[8] M.Pianizza,A.Barbucci,R.Ricotti,G.Cerisola, Sep.Purif.Technol, 54 (2007) 382-
387.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
204
Nº REF.: P541
Construction and characterization of dimensional stable anodes with iridium and tantalium by painting, immersion and electrophoretic
deposition for the electrokinetic treatment of polluted soil by hydrocarbon
R. A. Herradaa, A. Medel,
b F. Manríqueza, E. Bustos
a*
a Centro de Investigación y Desarrollo Tecnológico en Electroquímica, S.C. Parque
Tecnológico Querétaro, Sanfandila, Pedro Escobedo, 76703 Querétaro, México. b Universidad de Barcelona, Facultad de Química, Martí i Franquès, 1 08028
Barcelona.
The electrokinetic treatment (EKT) of polluted soils by organic and inorganic
compounds has been developed five years ago at CIDETEQ with an efficiency close to
80 % in less than 8 hours developing the EKT in situ or ex situ. EKT is developing
applying direct current between at least two electrodes (anode and cathode), which are
placed into the soil to be treated, when passing current between the electrodes there are
different transport processes, as electro-migration, electro-osmosis, electrophoresis and
electrolysis of water. These processes have been reported in the literature, one of them
is showed in Figure 1 [1-2].
Figure 1. Representation of the circular 2D arrangement of anodes (+) around the cathode (-)
extracting the support electrolyte with the hydrocarbon (A) and using a power supply (B).
There are different factors that can be tested to continue improving this technology. A
critical factor that is nowadays under investigation is the material and the coating of the
working electrode, due to their crucial influence on the global efficiency of the EKT.
For EKT different coated electrodes have been used as IrO2, SnO2 and Ta2O5, which
generate chemisorbed hydroxyl radicals (OH) at interface level by the highest oxidation
over potentials and roughness, properties that favor the transformation or degradation of
organic compounds as hydrocarbons (HC).
The main goal of this research is modified titanium electrodes starting from the same
modifier solution (which includes iridium and tantalium) but using three different
deposition techniques: immersion, painting and electrophoretic deposition to construct
these dimensional stable anodes for the EKR of polluted soil by hydrocarbon (HC).
+
+
+
+
+ +
- A
A
B
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
205
The modified surfaces were characterized by Raman spectroscopy, Cyclic Voltammetry
(CV), Electrochemical Impedance Spectroscopy (EIS), Diffraction X-Ray (DRX),
perfilometry, Scanning Emission Microscopy (SEM) and Energy Dispersive X-Ray
spectroscopy (EDX). The production of OH was made by Electron Paramagnetic
Resonance (EPR) and UV-Vis spectrophotometry. Additionally, the HC removal was
evaluated using UV-Vis, Gas Chromatography couple Flame Ionization Detector (GC-
FID) and Chemical Oxygen Demand (COD).
References
[1] E. Bustos, J. Cárdenas, M. Pérez, B. Ochoa. Patente MX/a/2014/000833.
[2] M. Pérez – Corona, B. Ochoa, J. Cárdenas, G. Hernández, S. Solís, R.
Fernández, M. Teutli, E. Bustos. Recent. Res. Devel. Electrochem. (2013) 9: 59-
80.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
206
Nº REF.: P573
Enhancing solutions for electrokinetic remediation of dredged sediments polluted with fuel
F. Rozasa, M. Castellote*
b
a,b Institute of Construction Science Eduardo Torroja, IETcc-CSIC. 28033, Madrid
Spain
Since most organic contaminants do not have a net negative or positive charge, zeta
potential, is one of the most important parameters concerning their transport because
this potential controls the direction and rate of the EOF; therefore, ionic surfactants
seem to be the most appropriate, to remove them, as they introduce charged species that
can be moved by electromigration. However, non-ionic surfactants are often used
because of their lower critical micelle concentration compared to ionic surfactants,
higher degree of surface-tension reduction, and relatively constant properties in the presence of salt, which result in better performance and lower concentration requirements [1,2]. Maybe for this reason, as well as because of the complex matrix/surfactant/contaminant interactions, the results found in the literature concerning
the use of surfactants in the electrokinetic remediation of organic compounds are sometimes contradictory [3-7].
In this paper electrokinetic remediation experiments of dredged material from a harbour
contaminated with automotive fuel have been carried out. The removal was
investigated testing a total of 22 different experimental conditions analysing the
influence of different enhancing solutions as three commercial non ionic surfactants,
one biosurfactant, one complexing agent and one weak acid. The results obtained have
been explained on the basis of the interactions between the contaminants and the
enhancing electrolytes with the matrix, analysing the influence of the z-potential,
electro-osmotic flow and enhancing chemicals in the removal of fuel. For one specific
system, the electrophoretic zeta potential of the contaminated matrix in a solution has
found to be related to the electroosmotic averaged zeta potential in the experiment, and
not to the efficiency in extraction.
Figure 1. Decontamination percentages in the remediation experiments in function of (C +
EH), where C =contribution of contaminant and the EH= contribution of enhancing solution
y = 5.7163xR² = 0.9532
0
25
50
75
100
0 5 10 15 20
deco
nta
min
ati
on
/ %
(C+EH),/mV
b)
0
5
10
15
20
C ESa)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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The efficiency of the extraction has been correlated to a parameter accounting for two
contributions, fuel and surfactant, calculated on the basis of differences in the
electrophoretic zeta potential in different conditions (Figure 1).
This reveals the necessity of selecting the most appropriate surfactant by making prior
tests of interactions between the contaminants/enhancing electrolytes/matrix, seeming to
be the zeta potentials obtained in these additional tests, the key parameter for assessing
the remediation efficiency.
References
[1] Y. H. Shen, Sorption of non-ionic surfactants to soil: the role of soil mineral
composition. Chemosphere 41 (2000) 711–716.
[2] J. W. Yang, Y. J. Lee, Electrokinetic removal of PAHs, in: K. R. Reddy, C.
Cameselle, Electrochemical Remediation Technologies for Polluted Soils,
Sediments and Groundwater. Wiley, New-Jersey, 2009, pp. 197–217.
[3] S. D. Haigh, A review of the interaction of surfactants with organic contaminants
in soil. Sci. Total Environ. 185 (1996) 161–170.
[4] R. E. Saichek, K. R. Reddy, Electrokinetically enhanced remediation of
hydrophobic organic compounds in soils: A review. Crit. Rev. Environ. Sci.
Technol. 35 (2005) 115–192.
[5] C. Cameselle, K. R. Reddy, Development and 385 enhancement of electro-
osmotic flow for the removal of contaminants from soils. Electrochim. Acta 86
(2012) 10–22.
[6] M. Pazos, O. Iglesias, J. Gómez, E. Rosales, M. A. Sanromán. Remediation of
contaminated marine sediment using electrokinetic-Fenton technology. J. Ind.
Eng. Chem. 19(3) (2013) 932–937.
[7] K. Maturi, K. R. Reddy. Simultaneous removal of organic compounds and heavy
metals from soils by electrokinetic remediation with a modified cyclodextrin.
Chemosphere 63(6) (2006) 1022–1031.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº REF.: P576
Electrodescontamination of soils contaminated with dyes for industrial use.
Felipe Hernández-Luisa*
, Mario V. Vázquezb, Raquel Rodríguez-Raposo
a,
Domingo Grandosoa, Mariano Pérez
a, Graciliano Ruiz
a, Carmen D. Arbelo
c
a Departamento de Química (U.D. Química Física), Facultad de Ciencias (Sección
Química), Universidad de La Laguna, Tenerife, España b Grupo Interdisciplinario de Estudios Moleculares (GIEM), Instituto de Química,
Universidad de Antioquia, Medellín, Colombia c Departamento de Biología Animal, Edafología y Geología, Facultad de Ciencias
(Sección Biología), Universidad de La Laguna, Tenerife, España
*Corresponding author: [email protected] (Felipe Hernández Luis)
The problem of contaminated water and soils requires the constant development of
appropriate methodologies to eliminate different types of contaminant. In this sense, the
technical Electrokinetic remediation of soils (electroremediation) has been applied
successfully to mobilize a large number of pollutants, both organic and inorganic.
As it is well known, this technical Electrokinetic decontamination consists of, basically,
the application of an electric field between two inert electrodes that are in contact with
moist soil. This electric field gives rise to a series of transport phenomena which favour
the movement of both loaded and unloaded substances in soils, including Ionic
migration, electrophoresis, electro-osmotic flow and diffusion.
This paper presents some preliminary tests on soil decontamination (first synthetic and
then on natural soils with different characteristics contaminated with dissolutions of dye
commonly used in the industry.) This combines the technical Electrokinetic remediation
(electroremediacion) with the physical method of adsorption.
Some of these dyes-compounds are being studied by our interdisciplinary group and
among them we can mention the following:
Remazol Red 23
Fast Green FCF
Tartrazine
Remazol is a reactive dye chromospheres contains a substituent that reacts with the
substrate. Reactive dyes have good fastness properties owing to the bonding that occurs
during dyeing. Reactive dyes are most commonly used in dyeing of cellulose like cotton
or flax, but also wool is dye able with reactive dyes. Reactive dyeing is the most
important method for the coloration of cellulosic fibres, wool and nylon.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
209
Fast Green FCF is a sea green triarylmethane food dye. This substance has been found
to have carcinogenic effects in experimental animals, as well as mutagenic effects in
both experimental animals and humans. It furthermore risks irritation of eyes, skin,
digestive tract, and respiratory tract in its undiluted form.
Tartrazine is a synthetic lemon-yellow azo dye primarily used as a food coloring. It is
water soluble and is a commonly used colour all over the world, mainly for yellow.
Various types of medications include tartrazine to give a yellow, orange or green hue to
a liquid, capsule, pill, lotion, or gel, primarily for easy identification. Types of
pharmaceutical products that may contain tartrazine include vitamins, antacids, cold
medications (including cough drops and throat lozenges), lotions and prescription drugs.
Coloring-soil adsorption studies are underway simultaneously both by the Spanish
groups like the Colombian (first floor synthetic, as we said before, and then with natural
soils with high or low organic matter, to see the effect of the buffering power of the
soil).
The cells used are similar to those used in previous studies from our group, being the
dimensions of the cylinder containing the pasta soil : water 20 cm long by 2.5 cm in
diameter. The electrodes used were rods of graphite 8 cm2 in area exposed to the
dissolution.
The follow-up is being done by UV-V absorption spectrophotometry and as adsorbents;
once the dyes have been mobilized we tested the re-adsorption, mainly with cork and
sawdust of different tree species, previously subjected to a chemical pre-treatment.
References
[1] M.V. Vázquez, C.D. Arbelo, F. Hernández-Luis, D. Grandoso, M. Lemus,
Portugaliae Electrochimica 27 (2009) 419
[2] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, D. Grandoso, M. Lemus, D.
Benjumea, C.D. Arbelo, Geoderma 148 (2009) 261
[3] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, Land Contamination &
Reclamation 16 (2008) 249
[4] D. A. Vasco, C. Ramírez, D. M. Benjumea, F. Hernández-Luis, M. V. Vázquez,
Innovación 19 (2007) 15
Poster Session: EKR in combination with other techniques
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
213
Nº REF.: P646
Electrochemical dechlorination of TCE with mixtures of humic acid, metal ions and nitrates in a simulated karst groundwater
Noushin Fallahpoura, XuhuiMao
a,b, LjiljanaRajic
a, SonghuYuan
a,c, Akram N.
Alshawabkeha,*
aCivil and Environmental Engineering Department, Northeastern University, Boston,
MA, 02115, USA. bSchool of Resource and Environmental Science. Wuhan University, Wuhan City,
430072, P. R. China. cState Key Lab of Biogeology and Environmental Geology, China University of
Geosciences, Wuhan, 430074, P. R. China.
*Corresponding author: E-mail: [email protected]
Abstract
A small-scale flow-through limestone column was used to evaluate the effect of
common coexisting organic and inorganic compounds on the dechlorination of
trichloroethylene. An iron electrolysis system installed in the column was tested for the
treatment of contaminant mixtures in groundwater. The system consists of an iron anode
and a copper foam cathode. In the absence of humic acid (organic matters) and
dichromate, selenate, and nitrate (inorganic matters), 90% of initial TCE was
dechlorinated under optimum conditions (90 mA current, 1 mL/min flow rate, and 1
mg/L initial TCE concentration). As humic acid competes for the reactive sites on iron
anode with TCE, its aggregates inhibit the reduction rate of TCE to some extent. Metal
ions (strong oxidants) also compete with TCE for electron transformation. Dissolved
hexavalent chromium concentrations were reduced completely to trivalent chromium
due to the ferrous species from iron anode. TCE reduction rate was decreased by 1.5
times in the presence of dichromate. Selenate effect on TCE remediation rate was not as
strong as that of dichromate as the removal efficacy of TCE decreased by only 10%. In
addition, selenatecomplexation with dissolved iron released by iron anode corrosion
result in aggregates, which may coat the iron surface and decline dechlorination rate.
The present investigation indicates that the electrochemical reduction on a copper foam
cathode is capable to remediate TCE significantly (around 80%) even in the presence of
high concentration of nitrate (40 mg/L). Although the system presented here can clean a
mixture of contaminants, this system can be engineered and optimized to treat TCE in
mixtures with a relatively wide variety of contaminants.
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
214
Nº REF.: P651
Comparison on electrokinetics and soil flushing for removal of metals after in-situ soil mixing
Cha-Dol Lee1, Su-Won Lee
1, Eun-Ki Jeon
1, Kitae Baek
1, 2, *
1Department of Environmental Engineering, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do, Republic of Korea 2Department of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-
daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea
Corresponding authorTel: +82-63-270-2437, Fax: +82-63-270-2449,E-mail :
Generally, different principles should be applied to remove organic and inorganic
contaminants from soil. In Korea, biodegradation, chemical oxidation, and chemical
flushing are common remediation techniques for petroleum contaminated site, while
chemical extraction is the most common choice for metals-contaminated site. In this
study, the lab-scale batch experiments were carried out to remove contaminants using
combined process of chemical oxidation and extraction for mixed contaminated soil
with diesel and heavy metals.A sequence of oxidation-extraction and simultaneous
application showed similar removal of petroleum, while the sequence of extraction-
oxidation showed lower removal of petroleum. The oxidation process removed organic
pollutants effectively, however, the metals still remained in the soil. The metals could
be removed by soil flushing and electrokineticremediation. As a result, 10-30% of
heavy metals were removedby soil flushing and electrokinetics. EDTA was the most
effective to extract Cu and Pb compared to others from contaminated soils. This result
indicates that extraction and oxidation could be applied to remediate mixed wastes-
contaminated site with metals and petroleum.
Acknowledgement
This work was supported by KEITI through GAIA project (201200055003)
EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain
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Nº REF.: P675
Soils contaminated with drugs in common use: An attemp to use the electroremediation, in combination with the adsorptiom, on industrial
waste, as a prevention tool of contamination.
Felipe Hernández-Luisa*
, Mario V. Vázquezb, Elisa G. Carvajal
b, Sandra Dévora
c,
Susan Abdalác, Raquel Rodríguez-Raposo
a, Domingo Martín-Herrera
c, Carmen D.
Arbelod
a Departamento de Química (U.D. Química Física), Facultad de Ciencias (Sección
Química), Universidad de La Laguna, Tenerife, España b Grupo Interdisciplinario de Estudios Moleculares (GIEM), Instituto de Química,
Universidad de Antioquia, Medellín, Colombia c Unidad de Farmacología y Farmacognosia, Facultad de Ciencias de la Salud
(Sección Farmacia), Universidad de La Laguna, Tenerife, España d
Departamento de Biología Animal, Edafología y Geología, Facultad de Ciencias
(Sección Biología), Universidad de La Laguna, Tenerife, España
*Corresponding author: [email protected] (Felipe Hernández Luis)
New emerging contaminants listed more and more. Among others we can mention
powerful drugs such as anti-inflammatory agents, analgesics, antipyretics, etc. are being
used increasingly, often without medical supervision one. Non-steroidal anti-
inflammatory drugs (NSAIDs) are really an issue of growing concern in relation to their
presence in the environment, particularly in the soil and the water. An important issue
that is being conducted, on the more developed countries, is obviously control and
responsible consumption of these drugs through campaigns of awareness, as well as the
creation of recollection points of excess of such products, many of them expired, for
their subsequent destruction or controlled recycling.
Some of these compounds are being studied by our interdisciplinary group and among
them we can mention the following:
Paracetamol
Ibuprofen
Naproxen
Ketoprofen
Aspirin
Diclofenac
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In the case of soils, it is primarily interesting to analyze the extent of adsorption of these
compounds doing the corresponding adsorption isotherms for, and then define the
working conditions to mobilize these compounds in the studied matrix. Among others
there are to define the pH of the soil and solvents, chemical changes that can occur
before the changes of pH produced by the advance of the fronts of acidic and alkaline
electro-generated in the electrodics chambers, applied electric field and duration of the
experiment of electroremediacion, etc.
In the first phase of the experiments in which we find ourselves, we have used before a
natural soil, whose complexity is well known, a synthetic soil based on kaolin that is a
clay mineral, part of the group of industrial minerals, with the chemical composition
Al2Si2O5(OH)4. The results are promising, although we found some experimental
problems: with the quantification of the drug should be made by UV spectroscopy, it is
necessary that extraction solutions (mixing kaolin - dissolution of the drug), after being
filtered are perfectly transparent, so that it does not produce transmittance reading
errors. To do this, we must choose a proper particle size and a few suitable ultra-filters
vacuum.
Once we have solved partly these problems, the next step is to repeat the process with
natural soils. We have chosen two quite different characteristics: one with a high
content of organic matter (Ravelo) and another with less organic matter (Junquito) both
from the Tenerife Island (Canary-Spain). This is important since it affects the soil buffer
capacity and everything that brings with it. In parallel, our group of Colombia will try to
rehearse with two similar soils with lots of organic matter and another with low organic
matter collected in areas close to the city of Medellin (Antioquia Department).
The Colombian group, in addition to working with UV spectroscopy has made
preliminary studies with different variants of voltammetry, presenting quantification
fewer problems now which do not affect both the transparency of the dissolutions.
Once studied the adsorption soil-drugs and working conditions for the mobilization of
the latter by the application of an electric field, the next step is to locate industrial waste
cheap and easy-to-handle that hold the drugs and they can be removed for subsequent
treatment safely and efficiently. For now we are rehearsing with various adsorbents as
shells of fruits, cork, sawdust and even don’t have significant results that indicate the
goodness of the method, although, in principle, all allows us to be optimistic.
References
[1] M.V. Vázquez, C.D. Arbelo, F. Hernández-Luis, D. Grandoso, M. Lemus,
Portugaliae Electrochimica 27 (2009) 419
[2] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, D. Grandoso, M. Lemus, D.
Benjumea, C.D. Arbelo, Geoderma 148 (2009) 261
[3] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, Land Contamination &
Reclamation 16 (2008) 249
[4] D. A. Vasco, C. Ramírez, D. M. Benjumea, F. Hernández-Luis, M. V. Vázquez,
Innovación 19 (2007) 15