Treatment of Algae using the Kria Water Treatment System · 2017. 7. 5. · KRIA treatments could...

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Treatment of Algae using the Kria Water Treatment System

Victor F. Medina, Ph.D., P.E. Research Environmental Engineer

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Background

The KRIA Water Treatment System is a reactor that works by producing superoxide, a negatively charged oxygen radical, and charging it into the water body of interest using a recirculation cell.

Previous ERDC studies showed that the KRIA was effective at treatment of diesel and also enhanced removal of PCBs.

A video of the KRIA in action can be found at: https://www.youtube.com/watch?v=b3UJnz88Lxs&list=UU1o9qwSHbkghwo-HPbimbIQ

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https://www.youtube.com/watch?v=b3UJnz88Lxs&list=UU1o9qwSHbkghwo-HPbimbIQ

https://www.youtube.com/watch?v=b3UJnz88Lxs&list=UU1o9qwSHbkghwo-HPbimbIQ


Contributors

Chris Griggs, Research Chemist Catherine Thomas, Research Biologist Agnes Morrow, Chemist Roy Wade, Research Engineer

Direct questions and inquiries to Dr. Victor

Medina, [email protected], 601 634 4283

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mailto:[email protected]


The KRIA Reactor Field

Deployment of the KRIA

The KRIA in the laboratory

The recirculation pump

The superoxide generation system

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Superoxide Negatively charged oxygen (O2

-) Less reactive than hydroyxl or persulfate

radicals Can work both oxidatively & reductively Literature indicates reactions with a wide range

of contaminants, including carbon tetrachloride, nitroaromatic compounds, and hydrocarbons.

Shepard et al. (1998) showed degradation of microcystin toxin

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Other reactive mechanisms of the KRIA

Increases oxygen content promoting enhanced biodegradation

Microbubbles, which have been shown to degrade contaminants, disinfection, and promote contaminant desorption

Cavitation at the injection nozzle. May promote radical formation.

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Background studies

Determine how KRIA affects water quality Run KRIA in tap water in 55 gallon drum

reactors (50 gallons) With superoxide valve on and off Measure water quality parameters Measure superoxide (SO) production

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Background studies

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55 gallon drum reactors

KRIA superoxide reservoir with valve (orange) off

Multipurpose water quality meter


Impact of KRIA operation on Water Quality (55 gallon study)

Substantial increases in DO and DO saturation due to addition of oxygen (as superoxide), and elevated levels maintained after 24 hr recovery

Increase of conductivity due to addition of negative oxygen anion, which is largely maintained after 24 hr recovery.

ORP increased in open and closed (cavitation effect). 9

WQ Parameter SO Valve 0 10 30 60 80 13524 hr recovery

Open 20.33 20.85 21.62 23.65 23.18 23.06 21.03Closed 20.28 20.36 20.85 21.58 22.04 22.68Open 0.170 0.265 0.305 0.355 0.355 0.353 0.337Closed 0.136 0.138 0.139 0.146 0.149 0.150Open 8.63 30.21 30.62 30.41 30.16 29.37 28.55Closed 10.34 9.13 9.09 8.91 8.76 8.56Open 94.1 331.6 347.3 356.2 352.9 343.4 321.9Closed 113.0 101.0 102.0 100.8 100.7 100.0Open 5.95 6.44 6.65 6.93 6.99 6.92 6.65Closed 4.68 5.28 5.71 6.04 5.87 6.28Open -35.3 -23.0 -29.3 -46.3 -51.7 -59.6 -41.3Closed -22.5 -31.0 -32.7 -37.6 -36.8 -41.7

DO mg/L

DO %

pH

ORP

Mixing Time (minutes)

temp C

cond mS/cm


Superoxide measurement (using Superoxide Dimutase Assay)

Enzyme Linked Immunosorbent Assay (ELISA) based test Semi-quantitative measurement (relative comparison between

different treatments) Kria treated, with and without superoxide

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96-well microplate used in superoxide measurement

Plate reader


Superoxide

Enhanced superoxide activity in the superoxide treated reactor. Some activity found in control, possibly due to cavitation reactions

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0

200

400

600

800

1000

1200

1400

1600

0 1 2 3 4 5

Supe

roxi

de U

nits

Kria Operational Time (hrs)

Superox

Control


Algae Treatment Approach Obtained cyanobacteria from lake water from sources in

California and from Lake Eire, OH. Mixed 5 gallons with 45 gallons of preconditioned water

(tap water treated by ion exchange to make it suitable for fish growth).

Three treatments for California sample ► No treatment, control ► KRIA with superoxide valve off (KRIA w/SO) ► KRIA with superoxide valve on (KRIA w/o SO)

KRIA with superoxide only for Lake Erie Sample (Lake Erie)

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Experimental

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Bucket of collected algae used to spike 55 gallon drum reactors

55 gallon drum reactors with artificial lighting


Algae Treatment – Visual Comparison

Dramatic decrease in algae coloration and visible green particulate matter with KRIA treatment, with and without superoxide

Without superoxide actually produced a more clear end result after less treatment time, but the initial sample was noticeably less concentrated.

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Kria treated with Superoxide versus Control (40 min. treatment)

Kria treated without Superoxide versus Control (5 min. treatment)


Counts of Microcystin aeruginosa

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Study Treatment Initial Count (NU/mL) Final Count (NU/mL) %Count ChangeInitial Biovolume

(um3/mL)Final Biovolume

(um3/mL)%Biomass

ChangeControl 3.70E+07 3.08E+07 17% 1.72E+09 1.18E+09 32%Kria with Superoxide 3.40E+07 6.32E+06 81% 1.10E+09 2.16E+08 80%Kria without Superoxide 1.72E+07 1.17E+07 32% 5.34E+08 3.37E+08 37%

Study 3 - Lake Erie Kria with Superoxide 7.56E+05 5.81E+05 23% 3.83E+07 2.80E+07 27%

Study 2 - California Lake with High Cell Density

• Microcystin aeruginosa was counted by Phycotech, Inc. of St. Joseph, MI. • Microcystin aeruginosa accounted for 80 to 98% of the algal/cyanobacterial population by counts in control and post treated samples. • It was not possible to determine if cells were active (living) or not in the counting process. • The best treatment was achieved by the KRIA with superoxide, which had 80% reductions of counts and biomass


Volatile Matter (Organic Matter)

VM was used as a measure of biomass. KRIA treatment (w/ SO) resulted in a more than 80% reduction in VM (65% reduction

in control) in 40 minutes of treatment KRIA without SO had a 75% reduction in 5 minutes. Lake Erie study had a 65%

reduction.

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0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 10 20 30 40 50

Nor

mal

ized

Con

cent

ratio

n (C

/Co)

Treatment time (min)

Control

Kria


Spectrophotometer Scan

Spectrophotometer scan undertaken from electromagnetic spectrum from 600 to 700nm.

Drastic decrease in in adsorbance due to destruction of photosynthetic pigments.

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Chlorophyll

Chlorophyll concentrations dropped 80% in the Kria treated (w/ SO) reactor while actually increased in the control.

Decreases were also found in Kria w/o SO (90% in 5 min) and in the Lake Erie treated samples (75% in 5 min).

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0.0

2.0

4.0

6.0

8.0

10.0

12.0

0 10 20 30 40 50

Chl

orop

hyll

Con

cent

ratio

n (m

g/L)


Control

Kria


Turbidity

Turbidity is the measure of light scattering in water and is a function of particles in the water

Algal cells can act as light scattering particles The Kria Treated (w/ SO) sample had >90% reduction of turbidity after 40 minute

treatment. There was no reduction of turbidity in the control. Kria treated w/ SO and Lake Erie treatments had 84% reductions in turbidity after 5

minutes

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0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

1400.0

1600.0

0 10 20 30 40 50

Turb

idity

(NTU

)


Control

Kria


Microcystin Toxin Concentrations

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Study TreatmentTreatmemt time (min)

Time Zero Microcystin

Concentration (ug/L)

Post Treatment Microcystin

Concentration (ug/L) % Reduction

Control 40 146 138 5%Kria with Superoxide 40 146 34 77%Kria without Superoxide 40 138 44 68%Control 5 555 215 61%Kria with Superoxide 5 555 47 92%Kria without Superoxide 5 215 28 87%

Study 3 - Lake Erie Kria with Superoxide 5 5.5 1.8 67%

Study 1 - California Lake with Medium Cell Density

Study 2 - California Lake with High Cell Density

• Microcystin measured by GreenWater Laboratories (Palatka FL) using ELISA method with a detection limit of 0.15 ug/L after ultrasonication (to lyse cells) & filtration • KRIA treatments with and without superoxide charging resulted in substantial reduction of microcystin toxins compared to controls.


Issue - clogging

With the Lake Erie treatment, we found that some of the algae was in the form a stringy mat.

This clogged the metallic pretreatment column. We could only achieve treatment with further dilution of the sample

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Conclusions

The KRIA is effective at treating harmful algae, as supported by visual observations, counts of Microcystin aeruginosa, volatile matter, chlorophyll, and turbidity. ► Different measurements had different sensitivities.

Counts had the lowest, but could not differentiate between living and inactive

The treatment was also effective at substantially reducing microcystin toxin concentrations.

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Conclusions (continued) Effective treatment was generally found with and

without superoxide. ► Cavitation alone is an effective mechanism ► The literature indicates that cavitation can produce

radicals, including hydroxl radicals ► Superoxide did appear to enhance reduction of M.

aeruginosa counts ► Some differences in treatment maybe due to changes

in the initial reactor conditions 5 minute exposure in the drum was sufficient to

create effective change. Even lower exposure times maybe effective. 23


Questions Clogging issues

► Our studies used diluted samples –clogging could be a frequent issue

► Could the KRIA be modified to address this? How would the reactor work in an open water

deployment? ► Radius of influence? ► Residual effectiveness? ► Frequency of treatment?

Energy & costs? ► Is treatment ultimately cost-effective?

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Concept for Field Study

Construct some in place reactors to isolate the treatment in the lake. Apply KRIA treatment in one reactor, monitor changes in a control. Follow up with open water study to study treatment radius.

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Concept for Deployment We do not endorse this or other products, but are simply applying

our engineering knowledge to explore applications. KRIA treatments could be applied to bays, coves, and other areas

where HABs begin, either after monitoring suggests an imminent bloom or even just periodically. By controlling blooms in these sensitive areas, it may limit spread of HABs throughout a larger lake or reservior.

KRIA treatments can be applied to beaches or areas where human contract with HABs could occur

KRIA reactors could be deployed around water intakes, to provide preliminary treatment prior to intake into a potable water treatment system.

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Application around water intake

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Treatment of Algae using the Kria Water Treatment System · 2017. 7. 5. · KRIA treatments could...

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