Field Performance of Dispersive Colloidal Activated Carbon

Transcription

1 .yalpsid rieht tropustonseod gnisu era uoy tahtnoisrevtnioprewop eht,revewoh ;stnof dedebme sniatnocnoitatneserp siht stnof-dedebme-on/moc.redebmetnofnoitatneserp.w tisiv noitamrofni eromrof.redebme tnofnoitatneserp ybdeda eciton Field Performance of Dispersive Colloidal Activated Carbon Lessons Learned from Multiple Geological Settings Ashley Cedzo M Ed Jeremy Birnstingl PhD, Craig Sandefur MS, Kristen Thoreson PhD

2 Presentation Outline Background and technology basics *short recap: additional info available via webinar recordings Usage statistics and aggregate field performance to date Ensuring success Q&A

3 A new Class of Technology. A combination of sorption and enhanced bioremediation Activated carbon Previously and currently been used on the surface as a groundwater treatment technology Utilized in the subsurface for the last 5-10 years Regenesis R&D efforts (2007): Focus on use of particulate sorbents to bind dissolved contaminants in situ. Problem: Activated carbon and other sorbent particulates do not disperse in the aquifer waters and requires fracturing (grain displacement).

4 The Reagent what it is A highly dispersive, flow-able sorbent and microbial growth matrix Sorbent Rapid drop in dissolved-phase contaminant concentration Immediate risk-reduction Microbial growth matrix Accelerated bio-destruction of sorbed mass Ability to secure clean-up to much lower targets

5 The Reagent what it is Colloidal activated carbon (1 2 µm) Size of a bacterium suspends as liquid Huge surface area extremely fast sorption Proprietary anti-clumping / distribution supporting surface treatment (patent applied for) Core innovation Enables wide-area, low-pressure distribution through the soil matrix without clogging

6 Activated carbon facts- Granular Activated Carbon particles: > 1000 µm Powdered Activated Carbon particles: 40 to 100 micrometers diameter Agglomerate to >1000 µm in water Soil Pore Throat Diameter Silts/Sands Est. Range: 3-30 µm PROBLEM: Injecting granular or powder activated carbon requires fracturing of aquifer formation (grain displacement) due to large particle size and agglomeration. Results in: Inefficient placement Only partial treatment of subsurface Can compromise monitoring wells 2015 All Rights Reserved. REGENESIS and REGENESIS product(s) are registered trademarks of REGENESIS Remediation Products.

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8 Contaminants Sorbed, Now What? Primary Methods of Contaminant Destruction Aerobic Treatment Electron Acceptor Addition, Sparging Anaerobic Treatment Slow release electron donors Lactate, recirculation systems Enhanced Monitored Natural Attenuation All Rights Reserved. REGENESIS and REGENESIS product(s) are registered trademarks of REGENESIS Remediation Products.

9 PlumeStop : reagent distribution

10 PlumeStop Powdered Activated Carbon

11 Fracking PAC Compromises Monitoring Wells Sampling from this well does not accurately represent in-situ ground-water conditions at the specific point of sampling

12 PlumeStop LAC does NOT Compromise Monitoring Wells Sampling from this well accurately represents in-situ ground-water conditions at the specific point of sampling Regenesis PlumeStop Protocol for Flushing Wells

13 Fracture-emplaced Powdered Activated Carbon Flow-emplaced Liquid Activated Carbon Field application all about ensuring placement in flow-zones

14 - usage -

15 PLUMESTOP APPLICATIONS OCTOBER 2016

16 PlumeStop Applications July 2016 Principally Hydrocarbons (aerobic bio) = 31 Principally Solvents (anaerobic bio) = 31 Comingled / no dominant class = 4 Other contaminants of note PAH, freon-11, MtBE, TBA, chlorobenzene

17 All available site performance data pooled 24 sites Wells within expected zone of impact highlighted and assessed i.e. those wells within treatment grid and/or advective distance Total contaminant reductions monitored over time Performance histograms created full data set Initial capture Stability to date - performance analytics -

18 chlorinated ethanes (TCA, DCA, CA etc.) chlorinated ethenes (PCE, TCE, DCE, VC etc.) Freon-11 (CFC) TPH BTEX MTBE PAHs Chlorobenzene (MCB)

19 Data Set: Long term is up to 738 days Average is 199 days

20 Data Set: Long term is up to 738 days Average is 199 days

21 - How to ensure success? -

22 Pre-Application Design Verification

23 Flux-Zone (Design) Verification Testing What is flux-zone verification? Pre-application field-verification of remedial design parameters High-resolution identification of contaminant transport strata Undertaken by Regenesis design/injection personnel Enables accurate placement of reagents for maximum flux-interception Why is it necessary? Site investigations typically focus on liability and risk assessment Emphasis on contaminant identification, plume dimensions and migration pathways Flux-zone verification focuses on efficient reagent-contaminant contact Emphasis on identification of principal impacted strata, contaminant mass distribution and reagent delivery

24 Regenesis Flux-Zone Verification When is it undertaken? 4 6 weeks ahead of planned application Allows time for data analysis and design refinement What does it entail? Representative Soil Cores Field Hydrometer Testing Groundwater sampling/pid Readings Clear water injection testing Regenesis PlumeStop strategy of 100% success

25 Take Home We can now turn the subsurface into an activated carbon filter To capture contaminants and focus bioremediation Secure stringent targets faster manage back-diffusion To passively engineer plume dynamics Long term migration control without pumping Groundwater flow remains uninterrupted The retardation factor is now an engineering variable

26 Thank You Ashley Cedzo M Ed Northwest District Technical Manager Bend, OR acedzo@regenesis.com