up-front orders of magnitude reduction and accelerated bio ... · up-front orders of magnitude...

up-front orders of magnitude reduction and accelerated bio-destruction using a dispersive injectable reagent

Webinar: “Case studies and first EU projects”broadcast live on 3 November 2015

To watch the webinar recording visit regenesis.com/gb/webinars/

Principal technology features • Rapid reduc5on of groundwater concentra5ons •  Mul%ple order of magnitude concentra%on reduc%ons in days / weeks

• Accelera5on of contaminant biodegrada5on •  Elimina%on of low-‐concentra%on performance tailing •  Ability to secure stringent clean-‐up targets

• Wide subsurface dispersion •  Efficient fieldwork •  Ability to address areas of restricted access, deep plumes etc.

• Long-‐term efficacy •  The reagent is not consumed – it regenerates in situ

•  A highly dispersive, injectable sorbent and microbial growth matrix

•  Sorbent •  Rapid drop in dissolved-‐phase contaminant concentra%on •  Immediate risk-‐reduc%on

•  Microbial growth matrix •  Accelerated bio-‐destruc%on of sorbed mass •  Ability to secure clean-‐up to much lower targets

What it is

•  A highly dispersive, injectable sorbent and microbial growth matrix

•  Sorbent •  Rapid drop in dissolved-‐phase contaminant concentra%on •  Immediate risk-‐reduc%on

•  Microbial growth matrix •  Accelerated bio-‐destruc%on of sorbed mass •  Ability to secure clean-‐up to much lower targets

What it is

How does this work?

Bio Basics: Availability and Threshold Concentrations

•  Bacteria live on surfaces – biofilms •  Think ‘sink plug-hole slime’ or ‘dental plaque’ rather than ‘tadpoles’

•  They have to wait for their growth substrate (food) to come to them – they do not hunt•  They must therefore either sit on / in the food source (rotting vegetables)

•  Or wait for it to dissolve and come to them in solution (groundwater bioremediation)

•  As the plume is progressively cleaned up, the contaminant concentration drops•  The rate that substrate comes to the bacteria reduces

•  The rate that bacteria can therefore degrade it reduces – first order kinetics / half-life degradation

•  Furthermore, below a certain concentration, the rate can slow dramatically•  Threshold concentrations (Smin) for microbial growth – sufficient energy for activity – ‘starvation’ boundary

•  The threshold is variable but typically in the low µg/L range – therefore not relevant for every site

•  This step change slow-down is in addition to first-order diminishing returns

6,000 µg/L removed in first week

3,000 µg/L removed in second week

1,500 µg/L removed in third week

750 µg/L removed in fourth week 12.5% of initial weekly mass removal

6,000 µg/L removed in first week

3,000 µg/L removed in second week

1,500 µg/L removed in third week

750 µg/L removed in fourth week 12.5% of initial weekly mass removal

What if this (linear) rate could continue at this lower concentration….?

So this is the general idea – although the top end is accelerated too

•  Colloidal ac%vated carbon (1 – 2 µm) •  Size of a bacterium – suspends as ‘liquid’ •  Huge surface area – extremely fast sorp%on

•  Proprietary an%-‐clumping / distribu%on suppor%ng surface treatment (patent applied for) •  Core innova%on •  Enables wide-‐area, low-‐pressure distribu%on through the soil matrix without clogging

•  Low-‐solubility / controlled availability matrix nutrients •  Support in-‐matrix contaminant biodegrada%on •  Does not impact groundwater / eutrophica%on

What the reagent is

Fracture-emplaced PAC Dispersion-emplaced LAC

Example in Use- Mixed Solvents -

Case Study – Mixed VOC’s

•  Former electronics facility •  TCE 1,390 µg/L •  TCA 3,550 µg/L

•  Sand to silty-‐sand •  Depth to groundwater 3 – 4 m •  Seepage velocity 3.7 m/yr to the southwest

•  Test site injec%on of PlumeStop™ and HRC®

10 x reduc%on

100 x reduc%on

non-‐detect 1 year and coun%ng…

projected sorp%ve satura%on from influx

1000 x reduc%on

prolifera%on of VOC-‐degrading microflora -‐ dissolved-‐phase VOC at/close to ND -‐

18 months and coun%ng…

now >2 years…

- Distribution through Soil -

PlumeStop™: reagent distribution

PlumeStop Powdered Ac%vated Carbon








PlumeStop™: reagent distributionSEM image of sand particles without PlumeStop

PlumeStop™: reagent distributionSEM image of sand particle coated with PlumeStop


PlumeStop Distribu5on (Field-‐Prac5cal Distances)

•  Long Column Study –  16 foot length (5m) (ID 2”; 5 cm) –  Fine to medium silica sand (210 – 420 µm)

–  20% porosity (est.) (pore volume 0.5 gal; 2 L)

•  Breakthrough dynamics •  Retained carbon mass-‐balance

Influent

Effluent

Front progresses through dispersive flow

Post-flush residual coating visibly apparent

Clean chase-water Breakthrough at 1.2 PV

PlumeStop travelling >5 m

back-pressure / flow static – no permeability impact

PlumeStop applica5on (start/finish)

PlumeStop Distribu5on – wash-‐out?

•  Aggressive chase-‐water flushing –  Nine pore volumes immediately post-‐applica%on

(PlumeStop dispersive treatment s%ll ac%ve)

–  Equivalent seepage velocity of 35 km/year (22 miles/year)

•  Sacrificial dissec%on of column –  Broken into lengths and analyzed for elemental carbon

(corrected against clean-‐sand, pre-‐applica%on baseline)

Influent

Effluent

Total mass retained within column < 0.1% of pore volume 1-2 µm coating on sand particles

PlumeStop Distribu5on – Laboratory

Extreme-‐Case Test: •  Low surface charge, low surface area matrix

–  LAC reten%on on charged aquifer fines will be greater •  High wash-‐out flux

–  Volume and flow-‐rate >> field condi%ons –  PlumeStop dispersive treatment longevity ca. 1 – 3 months

•  Field-‐applica%on control opportuni%es –  Volume, flow-‐rate, dilu%on, chase-‐water, injec%on spacing, dispersion adjustment….

- Post-Sorption Degradation -- Bio-Regeneration -

PlumeStop Bioregenera5on -‐ Laboratory

Contaminant sorbs to sites available on PlumeStop par%cle

Microbes biodegrade sorbed

contaminants

Sorp%on sites become available for addi%onal contaminant

Principle:

•  Microcosm study (8 oz.; 230 ml) –  Test: water, lactate, soil, PlumeStop, inoculum (live) –  Control: water, lactate, soil, sodium azide (sterilized) –  Set-‐up: Equal volumes, no headspace, 27 reps. each

–  Loading: 10 mg/L PCE (net) added every two weeks –  Study period: 10 weeks

•  Dissolved-‐phase analysis (water only) •  Total system analysis (water and soil combined)

PlumeStop Bioregenera5on -‐ Laboratory

PlumeStop treatment: capture of spiked PCE – aqueous-phase protected

Control system: PCE concentrations in water climb with each injection

PlumeStop bio-‐regenerated

capacity

sorp%on onto soil Sorp%on onto soil plus PlumeStop

Theoretical aqueous-phase concentration without sorption

Theoretical aqueous-phase concentration soil + PlumeStop

PlumeStop treatment: Total PCE mass drops back to baseline between each spike –

Control system: Total PCE mass climbs with each injection

Sorption + degradation ∴ consistent with bio-regeneration

PlumeStop Bioregenera5on -‐ Results

•  PCE rapidly captured by PlumeStop –  Same day capture – aqueous phase (groundwater) cleaned up

•  Complete PCE degrada%on post-‐sorp%on –  PlumeStop treatment: PCE declines to zero between each spike (whole system)

•  Aqueous phase protec%on exceeds sorp%on capacity –  Evidence of sorp%on-‐site bio-‐regenera%on

•  Func%onal longevity extended (indefinitely) –  Significant opportuni%es for migra5ng plume capture – back-‐diffusion management

Q: Does biodegradation proceed post-sorption? A: Yes it does. Q: Is net contaminant degradation rate enhanced, inhibited or unaffected by

sorption into the biomatrix?

PlumeStop™: post-sorption biodegradation

Benzene Degradation Batch-Equilibrium Study•  Soil-water slurry microcosms

–  Treatment 1: with PlumeStop (live)–  Treatment 2: with PlumeStop (sterile)–  Treatment 3: no PlumeStop (sterile)–  Treatment 4: no PlumeStop (live)

•  Sampled destructively in triplicate–  Days 1, 7, 14, 21, 28

•  Water concentration monitored by head-space analysis•  Total benzene mass monitored by whole-system extraction


Rapid sorption in both PlumeStop treatments <1 day Ongoing drop in live PlumeStop and live soil control ∴ likely to be bio But could it be a sorption artifact?


Total system extract – soil and water No net loss in either sterile system, with or without PlumeStop Both non-sterile systems show benzene reduction Degradation significantly faster in the PlumeStop system

Howard et al (1991) “Handbook of Environmental Degrada:on Rates.” Lewis Publishers Inc. ISBN 0-‐87371-‐358-‐3

What if this (linear) rate could continue at this lower concentration….?

So this is the general idea – although the top end is accelerated too

–performance –

chlorinated solvents – post-sorption degradation – lines of evidence

Background•  Groundwater bioremediation progress

–  Typically monitored in the dissolved phase

–  Lines of evidence approach – multiple parameters

•  PlumeStop™ - sorption precedes degradation–  Contaminant and daughter products drop to below detection limits

–  What verification lines of evidence for degradation remain open?

•  Case study example –  Geochemical and microbial diagnostic lines of evidence

California Site

•  Pilot test – single well•  Former dry cleaners•  Modest µg/L PCE residue

California Site•  ‘Dune Sand’ formation

•  10 m/year groundwater flow

•  High redox conditions (aerobic)

•  No attenuation evident

•  PCE 550 µg/L

•  No daughter products

•  PlumeStop™

•  Electron donor and bacteria

Pilot Test Arrangement

Historic Data

Steadily increasing PCE

No daughter products

(aerobic conditions)

(<0.5µg/L)

>99.9% reduc5on

Redox ‘sweet spot’ establishes Competing TEA’s decline

(note zero on 2o axis)

PCE immediately ⬇︎ to ND (<5µg/L) Micro parameters increase post-app then decrease after ～two months

225%

541%676%

(init. ND)3,000 x

(no methanogenesis)

< MQL (5 µg/L; 0.5µg/L) through 7 consecu%ve sampling rounds – 451 days (15 months) and coun%ng…

Data Summary•  >99% (two OOM) PCE concentration reduction within 14 days

–  550 µg/L to non-detect (<5 µg/L)

•  Optimal dehalorespiration conditions established–  Redox from +254 mV to -150 mV (±30 mV) ‘sweet spot’

–  Competing electron acceptors depleted

•  Post-inoculation microbial trends–  Increase then decrease in dechlorination species and enzymes

–  Consistent with solvent metabolism and depletion

Specifics•  DHC enzyme activity – provides strong indicator of degradation

–  Increase in tceA reductase and vinyl chloride reductase post-application

–  TCE and VC remain below detection limits in groundwater (<5µg/L)

•  Dechlorination species proliferate post-application–  Dehalococcoides spp., Dehalobacter spp., Dehalogenimonas spp. ⬆︎⬆–  Reasonable to assume they are growing on H2(aq) and solvent

•  Geochemical status favourable for dehalorespiration–  but not favourable for competing methanogenesis

–  therefore optimal for bioremediation performance and efficiency

Conclusions

•  PlumeStop™ - depletion of GW solvents to n/d within 19 days

•  Lines of evidence for post-sorption degradation secured

•  All data obtainable from groundwater samples alone

- commercial projects -

Case Study- Manufactured Gas Plant / PAHs -

Richmond IN

PlumeStop™ MGP

•  Silty clay loam transi%oning to sand and gravel

•  Globules of oil-‐like material in pore space

•  Injec%on 4.0 – 6.7 mbgl •  PlumeStop™ •  ORC-‐Advanced®

Average dissolved-phase reduction 95% (to reporting limit)

Post-treatment concentrations all below RISC residential and/or 0.5 µg/L

Case Study- Migrating Plume – Barrier Application -

North Carolina

PlumeStop™ -‐ Migra5on Cut-‐off Barrier

•  Former Industrial Dry Cleaner •  PCE residues •  Pilot Barrier •  Mul%ple targeted forma%ons •  2.75 – 12.5 mbgl

•  Silty Sand (ca. 1.4 to 5.3x10-‐4 cm/sec)

•  Seepage Velocity ca. 22 m/year

•  HRC® BDI® PlumeStop™

99.7% reduc%on 94.2% reduc%on

[DEGRADATION TREND EXAMPLE]

Case Study- Deep Plume Treatment -

West Allis, WI

PlumeStop™ -‐ Deep Plume Treatment

•  Former Dry Cleaner •  PCE residues •  Vadose soil mixing •  RegenOx® ISCO •  Deep plume treatment •  24 – 27 mbgl

•  HRC®, BDI®, PlumeStop™

98.6% reduc%on 99.7% reduc%on 99.8% reduc%on

Case Study- Filling Station – BTEX Residues -

Pennsylvania

PlumeStop™ -‐ Filling Sta5on

•  Former Filling Sta%on •  BTEX residues •  Pilot Applica%on •  Tight forma5on •  2.75 – 4.5 mbgl

•  Clay with Sand (ca. 3.53x10-‐7 cm/sec)

•  Seepage Velocity Zero •  ORC-‐Advanced®, PlumeStop™

<0.5 µg/L >98.3% reduc%on

Case Study- Inner-City Development / Time Pressure -

Downtown Chicago

•  Neighborhood of McCormick Place – Central Chicago –  New Sports Stadium –  New Hotel Complex

•  Solvent residues •  Tight 5me window •  High cost implica5ons of delay •  Key remedia5on requirement: FAST

Case Study: Inner City Development – Time Pressure

Case Study: Inner City Development – Time Pressure

•  Why the 5ght 5me window? – Weren’t the solvent residues known?

•  Access restric5ons – historic buildings –  Precluded early start

•  Problem was moved aside

Case Study: Inner City Development – Time Pressure •  PCE and TCE residues – up to 7,440 µg/L •  Sand forma%on over clay

–  Treatment area 300 m x 500 m – (1,000’ x 1,600’) –  Treatment Zone 3 – 7 mbgl -‐ (10’ – 22’)

•  Enhanced bio: HRC®, BDI® –  Sufficient to address the contamina%on

•  PlumeStop™ –  Rapid risk reduc%on and bio process accelera%on –  Take the bio process out of the groundwater phase

•  19 days’ fieldwork on site (Chicago winter) –  138 direct-‐push injec%ons – no resident equipment

96.9% reduc%on Total VOC

96.5% reduc%on Total VOC 92.3% ∑ VOC MCL 567 µg/L

TCE MCL 242 µg/L (site works / access restric%ons – no groundwater data)



Compositional changes consistent with biodegradation

92.3% ∑ VOC MCL 567 µg/L

TCE MCL 242 µg/L (site works / access restric%ons – no groundwater data)

83% reduc%on Total VOC

84% reduc%on Total VOC

Compositional changes consistent with biodegradation

79%

TCE MCL 242 µg/L

∑ VOC MCL 567 µg/L

(site works / access restric%ons – no groundwater data)

Chicago Site -‐ Status •  Rapid reduc%on in groundwater contamina%on

–  80 – 97% from first sampling interval (total solvents)

•  Bio condi%ons established (redox, TOC, microbial numbers) –  Parent/daughter compound ra%o shivs (dissolved phase) –  (consistent with biodegrada%on)

•  ∑VOC targets met – from first sampling round (through all rounds) •  TCE targets met – from second sampling round (and degrading fast) •  Comple%on report submiwed (June 2015) •  No further ac%on required

Case Study- Rail Terminal – Solvent Residues -

Bologna, Italy

•

Two components

•  Laboratory tests – basic principles –  Dispersion –  Contaminant capture

•  Field Pilot – real-‐world prac%cality – Method of applica%on –  Placement valida%on

Laboratory Test Program – University of Rome Sapienza

•  Dispersion of PlumeStop through columns –  Sand column –  Sand and clay column

•  Contaminant capture by residual coa%ng –  Sand column –  Sand and clay column

Laboratory Test Program – Dispersion

Sand Column Clay and Sand Column

Laboratory Test Program – Capture

Laboratory Test Program – Capture

PlumeStop™ -‐ Bologna Rail Sta5on •  Major rail sta%on upgrade •  Solvent residues (ca. 100 µg/L) •  Pilot Applica%on

•  Complex alluvial forma5on –  Fine Sand + Silt (ca. 7.5 x10-‐4 cm/sec)

•  6.0 – 8.0 mbgl •  5.0 m/year seepage velocity

–  Fine to Med Sand (ca. 7.5x10-‐3 cm/sec) •  17 -‐ 19 mbgl •  50 m/year seepage velocity

•  HRC®, PlumeStop™ •  Field applica5on tests

PlumeStop™ -‐ Bologna Rail Sta5on – Field Applica5on

PlumeStop™ -‐ Bologna Rail Sta5on – Field Applica5on

PlumeStop™ -‐ Bologna Rail Sta5on – Placement Valida5on

Entry into monitoring wells: - Weak evidence of placement

Confirmatory soil coring: - Strong evidence of placement


•  Fine Sand + Silt (ca. 7.5 x10-‐4 cm/sec) •  6.0 – 8.0 mbgl •  5.0 m/year seepage velocity

post-‐applica%on pre-‐applica%on Visual indications of evenly dispersed dark material No visible fracture or ‘soil parting’ placement


Visual indications of evenly dispersed dark material No visible fracture or ‘soil parting’ placement

•  Fine Sand + Silt (ca. 7.5 x10-‐4 cm/sec) •  8.0 – 9.0 mbgl •  ca. 5.0 m/year seepage velocity

post-‐applica%on pre-‐applica%on


Visual indications of evenly dispersed dark material No visible fracture or ‘soil parting’ placement

•  Sand and gravel layer •  9.0 – 10.5 mbgl






“Effective foc” – activated carbon sorption >> organic carbon sorption Plots show factor of 50 – 100 x The factor estimated for TCE is significantly higher

PlumeStop™ -‐ Bologna Rail Sta5on – Sorp5ve Efficacy


•  Soil from cores tested for contaminant capture in lab

•  Batch-‐equilibrium study •  20 g water; 5.0 g core soil •  Triplicate samples

•  PCE: 2,800 µg/L •  TCE: 7,100 µg/L ca. 100 x site concentrations

PlumeStop™ -‐ Bologna Rail Sta5on – Retained Sorp5ve Efficacy

-‐ preliminary data -‐ PCE: 100% capture in all samples (2,800 µg/L)

Bologna Centrale: Status

•  Field Pilot – real-‐world prac%cality – Method of applica%on ☑︎ –  Placement valida%on ☑︎

•  First field sampling data imminent –  (not quite in %me for webinar)

•  Full scale applica5on approved –  Scheduled for January 2016

Europe Status

Europe Status

•  Eight further projects scheduled in next 4 – 5 months –  United Kingdom –  Belgium –  Italy

•  30 further projects in design phase •  Wide interest everywhere

–  Ireland to Poland – Scandinavia to Mediterranean

•  Wide regulatory acceptance

- usage indicators -

1.  When time is critical

2.  To secure stringent clean-up targets

3.  For passive control of migrating contamination

4.  As a long–term means of addressing matrix back-diffusion

PlumeStop™ – product usage indicators


1.  When time is critical

The fastest groundwater remediation technology available today?

•  Immediate risk reduction secured through sorption(especially fast due to high relative surface area and wide dispersion)

•  Long-term destruction secured through in-matrix biodegradation(accelerated degradation achieving bio-regeneration of sorption sites)


2.  For securing stringent clean-up targets

•  Low µg/L targets are challenging for all technologies

•  Bio typically performs comparatively well, but at very low concentrations, substrate availability becomes insufficient to support microbial activity

•  PlumeStop accumulates low-level contaminants into the bio-matrix until concentrations become sufficient within the matrix to support an active microflora while keeping contaminants out of the groundwater


3.  Passive control of migrating diffuse contamination

Used in barrier formation to capture diffuse contaminants

•  Concentration of contaminants in matrix for locally intensive treatment

•  Tighter capture zone than bio-barriers alone(especially valuable where space is limited and/or groundwater is fast-flowing)

•  Faster destruction rates and greater timing tolerance between (bio) amendment applications – if still needed


4.  A long–term means of addressing matrix back-diffusion (i.e. diffusion-driven rebound)

•  PlumeStop maintains a concentration gradient out of the immobile porosity

•  Mobile porosity contaminant conc. remains low due to capture by PlumeStop

•  Sorption sites regenerate due to accelerated in-matrix biodegradation

•  The product is not consumed and remains functional – theoretically for decades

Contaminant diffuses out of

immobile porosity

Biodegrada%on accelerated within the matrix

Mobile-‐porosity concentra%ons

decline / remain low

Sorp%on sites are regenerated

GW contaminants par%%on into the

PlumeStop

Back-‐diffusion gradient

created / sustained

Bacteria and substrate are concentrated

together

- close -

PlumeStop – positioning within Regenesis product range

•  Used to further increase bioremediation performance

•  Reduced treatment times•  Achieve very low target concentrations (low µg/L range)

•  Can be co-applied with electron donor/acceptor technologies•  Aerobic bioremediation – e.g. with ORC-Advanced®

•  Anaerobic bioremediation – e.g. with HRC®

•  Used as a standalone treatment •  Where natural donor/acceptor supply is adequate •  E.g. migrating plume management – back-diffusion management

PlumeStop – further information

•  www.regenesis.com – case studies, tech bulletins, and

•  white Paper – technology detail & supporting science

Tech Bulle5ns – available online: click here

http://regenesis.com/gb/remediation-products/plumestop-liquid-activated-carbon/

Tech Bulle5ns – available online: click here

http://regenesis.com/gb/remediation-products/plumestop-liquid-activated-carbon/

up-front orders of magnitude reduction and accelerated bio-destruction using a dispersive injectable reagent

Ques5ons?

www.regenesis.com

Jeremy Birns+ngl Ph.D. B.Sc. MSEE, CEnv

Vice President

Environmental Technology

+44 1225 731 446

Bath, UK

[email protected]

Thank You

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up-front orders of magnitude reduction and accelerated bio ... · up-front orders of magnitude...

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