Treatment of a TCE DNAPL Source Using Fenton s Reagent. Naval Training Center Orlando April 6, 2005

Transcription

1 Treatment of a TCE DNAPL Source Using Fenton s Reagent Naval Training Center Orlando April 6,

2 SA17 - NTC Orlando 9-acre site formerly served as Defense Property Disposal Office (DPDO) High concentrations of TCE and daughter products in soil and groundwater Depth To GW about 5 ft bls Aquifer consists of interbedded sands and clays Most Contamination located between 10 and 40 ft bls 2

3 3 SA 17 Site Cross Section

4 Remedial Action Objectives Treat groundwater to concentrations less than 500 ppb total CVOCs Since site showed strong indication of natural attenuation, NA would take care of lower concentrations 4

5 Technology Selected Orlando Partnering Team (OPT) selected ISCO using Fenton s Reagent Injected at peroxide concentrations of up to 25- percent 5

6 6

7 Overview of ISCO Treatment and Sampling at SA17 7 Injection Events Nov 00/Jan 01 Mar Aug 2002 Sep 2002 Total of 100,000 lbs of peroxide injected Sampling Events Base Line Post-Phase 1 Mar 02 Apr 02 Jul 02 Oct 02 Jan 03 Jun 03

8 8 CVOCs > 1000 ug/l Before and After ISCO at SA 17

9 9 Source area still remains at SA 17

10 ISCO Assessment at SA Partial mass removal accomplished Dissolved phase plume TCE concentrations reduced by 88 percent ISCO unable to treat some portions of source area reasons include lack of hydraulic connection, preferential flow paths, diffusion limiting conditions Residual source area continues to release TCE to groundwater

11 Current Status for SA 17 Diffuse portion of plume treated to levels that allows natural attenuation Defined source area exists in tighter soils at several discrete depths Site has quickly converted from oxic conditions associated with ISCO to those that facilitate ERD Ethene and ethane reported through out site DHC reported with in-situ microcosms Enhanced biological treatment using Emulsified Oil Substrate will be used to control flux from the residual source MNA will be used for dilute downgradient portion of plume 11

12 DNAPL RECOVERY OPERATIONS: FROM PUMP-AND-TREAT TO SEAR APPLICATION Operable Unit 2 Hill AFB, Utah ACEC Innovative Technologies Meeting April 6, 2005 Charles Holbert, Ph.D. URS Corporation 756 E. Winchester St., Suite 400 SLC, Utah chuck_holbert@urscorp.com 12

13 Acknowledgements Kyle Gorder Ray Spencer Rhonda Hampton Mike Annable Carl Enfield Lynn Wood Michael Brooks Stacey Arens Curt Himle Bruce McCormack John Barlow Steve Snelgrove Hans Meinardus Hill Air Force Base Hill Air Force Base AFCEE University of Florida U.S. EPA U.S. EPA U.S. EPA URS URS URS URS URS INTERA 13

14 Operable Unit 2 Site Location Located 25 miles north of SLC, Utah on the northeast boundary of Hill Air Force Base Used from 1967 to 1975 to dispose of spent degreasing solvents in two unlined trenches 14

15 Operable Unit 2 Contamination Bentonite Slurry Containment Wall (1,500 ft in length and 60 to 90 ft bgs) 10 µg/l TCE Isoconcentration Surface Hill AFB Boundary North Interceptor Trench (NIT) 1,000 µg/l TCE Isoconcentration Surface Soil Stratigraphy N Well casing shown in black and screen interval shown in red. 15

16 Surface of Clay Aquitard in Source Area Panel 5 Panel 2 Panel 4 Panel 3 Panel Historical Maximum DNAPL Elevation Containment Wall Boundary Panel Boundary 16

17 Estimated DNAPL Extent in 1991 Containment Wall Estimated extent of paleochannel. Panel 4 Panel 3 Panel 2 Panel 1 Panel 5 Original Source Recovery Well Red contour represents the historical maximum DNAPL elevation of 4,654 ft amsl. 17

18 Pump-and-Treat Source Recovery System (SRS) constructed in 1992 as interim action to recover mobile DNAPL five (5) wells installed in channel DNAPL / contaminated groundwater treated via phase separation and steam stripping Over 40,000 gallons of DNAPL recovered DNAPL no longer recovered at original extraction wells 18

19 Enhanced Recovery Steam Flood (1997) treated area dewatered and subjected to soil vapor extraction for three weeks followed by steam flooding for one additional week 900 gallons of DNAPL recovered evidence suggests DNAPL was mobilized outside the test area Panel 2 Surfactant Flood (2000) flooding conducted for ~ 30 days using 8 wt% sodium dihexyl sulfosuccinate (44,000 kg) and 4.5 wt% isopropyl alcohol (23,000 kg) 430 gallons of DNAPL recovered from 64,000 gallon swept pore volume post-sear PITT indicated 34 gallons of DNAPL remaining 292 gallons of DNAPL recovered over a four year period following the SEAR 19

20 Enhanced Recovery cont. Panels 1 & 5 Surfactant / Foam Floods ( ) two full-scale applications conducted using foam for mobility control each flood conducted for ~ 30 days using 4 wt% sodium dihexyl sulfosuccinate (49,000 kg total) 1,385 gallons of DNAPL recovered from 83,000 gallon swept pore volume less than 1 gallon of DNAPL recovered from the treated areas since completion of the floods 20

21 SEAR Field Setup North South Extraction Wells Injection Wells (3) Extraction Wells Electrolyte (Brine) Staging Surfactant/Alcohol Staging Surfactant/Alcohol Staging Mixing / Injection On-line GC SCADA, Flow Control, Autosampling 21

22 Post-SEAR DNAPL Recovery Following the surfactant flood in Panel 2, DNAPL was identified in a localized depression in the top of the clay aquitard. Mobile DNAPL recovery was conducted using a portable DNAPL pump assembly. Microemulsion DNAPL 22

23 Remaining DNAPL The majority of DNAPL remaining in the OU 2 source area is suspected to be present as a low interfacial tension fluid pooled via gravity drainage in localized depressions contained in the surface of the underlying clay aquitard. Silty Clay Sand and Gravel Water Table Clay DNAPL Medium to Fine Sand 23

24 Pre-Source Recovery Conceptualization U2-032 Alpine Clay Surface U2-031 U2-001 U2-033R U2-034 Red contour represents the historical maximum DNAPL elevation of 4,654 ft amsl. Containment Wall 24

25 Post-Source Recovery Conceptualization U2-032 U2-238 Alpine Clay Surface U2-031 U2-001 U2-033R U2-139 U2-034 Estimated extent of DNAPL (4,643.8 ft amsl) based on interface probe readings. Containment Wall 25

26 Portable DNAPL Recovery ( ) DNAPL Recovery (gals)

27 Panel 5 Mass Flux Investigation Mass Flux Wells Surface of the Clay Aquitard Surfactant / Foam Flood Treatment Area 27

28 Contaminant Flux (grams/day) Pre-SEAR mass flux measurements of TCE Wells shown from south to north Flux Meter Pumping Test - Min Pumping Test - Max Contaminant Flux (grams/day) Well Flux Meter Pumping Test - Min Pumping Test - Max Well Post-SEAR mass flux measurements of TCE 28

29 Contaminant Flux (grams/day) Post-SEAR pump test mass flux measurements TCE and cis-1,2-dce Wells shown from south to north cis-1,2-dce TCE Contaminant Flux (grams/day) cis-1,2-dce TCE Well Well Post-SEAR flux meter mass flux measurements TCE and cis-1,2-dce 29

30 Average Concentrations in Mass Flux Wells Apr-02 Jun-02 Aug-02 Oct-02 Dec-02 Feb-03 Apr-03 Jun-03 Aug-03 Oct-03 Dec-03 Feb-04 Apr-04 Jun-04 Aug-04 Oct-04 Dec-04 TCE Concentration (mg/l) Surfactant / Foam Flood cis-1,2-dce TCE cis -1,2-DCE Concentration (mg/l) 30

31 DNAPL Recovery ( ) 50,000 18,000 Cumulative Recovery Cumulative DNAPL Recovery (gal) 40,000 30,000 20,000 10,000 Annual Recovery Panels 2 & 3 Steam Flood Panel 5 DNAPL Pumping Panel 1 Surfactant / Foam Flood Panel 2 SEAR Panel 5 Surfactant / Foam Flood 14,400 10,800 7,200 3,600 Annual DNAPL Recovery (gal)

32 Biopolishing Evaluation Objective Evaluate carbon donor and microbial inocula amendment for remediation of source material previously treated by surfactant flooding Treatments Investigated Soil Control Emulsified Oil with Bachman Road (BR) Culture HRC-X TM with Bio-Dechlor INOCULUM TM Emulsified Oil Control Incremental Emulsified Oil with BR Culture Incremental Emulsified Oil 32

33 Biopolishing Evaluation Treatment Description Soil control (no donor or inocula) Emulsified oil with BR culture HRC-X with BDI culture Emulsified oil control (no inocula) Four increments emulsified oil with BR culture Four increments emulsified oil control (no inocula) (1) Based on a 71-day incubation period. Complete Transformation TCE to Ethene (1) No Yes No No Yes No MIBK concentrations reduced to zero in all biotic reactors after 7 to 10 weeks of aerobic incubation. 33

34 In Situ Chemical Oxidation Using Permanganate for Remediation of Chlorinated VOCs in Fractured Shale Andrew Vitolins, PG Malcolm Pirnie, Inc. Albany, New York 34

35 Watervliet Arsenal Watervliet Arsenal Hudson River Troy 35

36 Watervliet Arsenal Suspected degreaser source PCE concentrations greater than 170 mg/l at source Depth to bedrock ~15 feet bgs Contamination down to 150 ft. bgs Hudson River 36

37 Characterization Where is the mass? Fractures Multi-level level Sampling Hydrogeophysical evaluation Rock Matrix Physical characteristics VOC concentrations in pore water 37

38 Multi-Level Sampling 38

39 Hydrogeophysical Characterization Fracture location, size, and orientation Transmissivit y Fracture Interconnecti on 39

40 Hydrogeophysical Characterization 40

41 Rock Matrix Depth (ft bgs) TCE TCE J 140 PCE PCE J Estimated Porewater VOC Concentration (ug/l) PCE Solubility ~ 200 mg/l Rock crushing and analysis conducted on core samples (Univ. of Waterloo) VOC concentrations in matrix pore water 41

42 Integrated Characterization LEGEND PCE CONCENTRATION TCE CONCENTRATION FLOW ZONE IDENTIFIED VIA HYDROGEOPHYSICAL TESTING LIKELY VOC MIGRATION PATHWAY BASED ON ROCK MATRIX TESTING 42

43 Integrated Characterization 43

44 Site Conceptual Model Lateral and vertical connectivity in the fracture system Also smaller, less transmissive, fracture pathways Bulk of VOC mass in rock matrix Φ m >> Φ f - greater storage capacity in matrix than in fractures Matrix diffusion 44

45 Matrix Diffusion Concentration gradient promotes diffusion into matrix Matrix becomes source Dissolved and/or sorbed DNAPL Parker et al.,

46 Remedial Strategy Rock matrix source treatment Permanganate (KMnO 4 ) Permanganate in fracture Contaminated Rock Matrix Early Time VOC Diffusion out of Matrix Permanganate Diffusion into Matrix Later Time B.L. Parker,

47 Pilot Study Evaluate KMnO 4 Delivery & Distribution Confirm VOC destruction by KMnO 4 Assess persistence of KMnO 4 Estimate degree & rate of MnO - 4 diffusion into shale matrix (lab studies at UW) Rock Oxidant Demand Tests Permanganate Invasion Testing Diffusion Rate Modeling 47

48 KMnO 4 Pilot Study Phase 1 KMnO 4 Injection One well at one depth 8,000 gallons of 2.5% solution Injection rates of to 22 psi Phase 2 KMnO 4 Injection 2 Westbay wells over several depths 5 Biweekly Injection Events Approx. 2,000 gallons per event Monthly field monitoring (CMTs & Westbay) 48

49 Phase I and II Injection Results ft Phase 2 injection Phase 1 injection ~250 ft 49

50 Carbon Isotopes Verify that decreases in VOCs caused by destruction, not displacement MnO 4 oxidation preferential for lighter isotope enrichment in C 13 Carbon Isotope (d 13 C) Date PCE TCE c-dce PCE TCE c-dce Well ID Sampled (ug/l) (ug/l) (ug/l) ( ) ( ) ( ) MW Feb MW Mar MW Mar nd MW Mar nd nd nd nd nd 50

51 Permanganate Persistence 20,000 18,000 16,000 14,000 Permanganate Concentration MW-74 12,000 10,000 8,000 6,000 4,000 2, /13/2002 7/3/2002 7/23/2002 8/12/2002 9/1/2002 9/21/ /11/ /31/ /20/ /10/ /30/2002 MW-74-1 MW-74-2 MW-74-3 MW-74-4 MW-74-5 MW

52 Rock Oxidant Demand ROD increases with increasing KMnO4 concentration 15 to 25 mg MnO - 4 /g rock Significant portion of ROD from oxidation of sulfide minerals (pyrite) University of Waterloo/University of New Brunswick,

53 Permanganate Invasion Elemental Manganese Profile after 6 weeks in 10 g/l KMnO4 solution Fracture Transect #1 Transect # Fracture Distance (mm) 53 University of Waterloo, 2003

54 Pilot Results Distribution and Effectiveness Permanganate easily distributed throughout fracture network Permanganate successfully oxidized VOCs Carbon isotope data indicated destruction of VOCs throughout system 54

55 Pilot Results Persistence and Invasion Majority of potassium permanganate consumed in less than three months Complete VOC rebound in most zones Injection volume not large enough for full treatment Large rock oxidant demand (ROD) Primarily due to pyrite (sulfide minerals) Matrix diffusion rates are slow 55

56 Conclusions Characterization of both aqueous and matrix contaminant distribution essential Remedial strategy Interpretation of results Characterization of rock oxidant demand critical Increasing demand with increasing concentration MnO - 4 appears to be a viable technology for CVOC-contaminated bedrock aquifers 56

57 Acknowledgments Daria Navon & Kenneth Goldstein Malcolm Pirnie, Inc. Beth Parker, John Cherry, & Steve Chapman University of Waterloo Steven Wood and Grant Anderson U.S. Army Corps of Engineers 57