Overview of ISGS™ Remediation Technology
Jim Mueller, PhD FMC Corporation
The NAPL Challenge – “Secondary Sources”
Primary Sources - Excavation and Disposal $100 to $250/yd3
Secondary Sources – More Challenging >$250/yd3
.
In the presence of an organic compound (R), MnO4 reactions yield an oxidized intermediate (Rox) or CO2 ,… plus MnO2 R + MnO4- → MnO2 + CO2 or Rox
ISGS™ Chemistry ISGS solution is a proprietary blend of permanganate and mineral salts that form a stable mineral precipitate
Birnessite is an oxide of Mn and Mg along with Na, Ca and K with the composition:
(Na,Ca,K)(Mg,Mn)Mn6O14.5H2O
Non-Treated Soil ISGS Treated Soil
Treated Soil Core Close-up Showing ISGS “Crust” or Coating and NAPL Ganglia
Likely NAPL
ISGS coating
Soil Grain
Epoxy (open pore space)
Conclusion: Soil grains and NAPL blobs coated with ISGS crust
Contaminant flux = f (HS, DS) HS - hydrodynamic structure DS – DNAPL architecture
Most contaminated Least contaminated
Pre-Remediation:
Source Zone
Control Plane
B
A’
A Contaminant
Flux (Jc)
Control Plane Control Plane
B
A’
B’
Contaminant Flux (Jc)
Post-Remediation: A
Contaminant Flux Definition (Enfield, 2001)
ISGS Potential Advantages
Rapid reaction yields reduced aquifer permeability and COI flux in days
Applicable to wide range of organic and inorganic COIs
Simple systems depending on site conditions
Little waste disposal
Relatively low cost for localized source areas
Long term (est. >15 years)
Logical alternative to mass removal
Field Pilot Tests Results Gainesville, FL
Cabot Carbon / Koppers Superfund Site, Gainesville, FL
• 90 acre site • Pump & treat in place • Secondary NAPL issues
DIP Parameter Value
Treatment area 2,000 ft2 Thickness of treatment interval (conservatively assumes 8 - 28 ft bgs)
20 ft
Soil density (estimated) 94.4 lbs/ft3 Soil mass within treatment area 3,778,000 lbs MnO4 to soil mass 3.2 g MnO4 / kg soil Mass NaMnO4 required for test plot 14,400 lbs Soil NOD 122 g MnO4 / Kg soil Application rate 10 % of soil pore vol Total volume 4.5% solution to inject 6,200 USG
Number of injection points 10 Volume 4.5% solution per point 620 USG Volume 4.5% NaMnO4 solution IP 155 USG
Direct Push Injections
ISGS Sealed Vertical Migration Pathways
4.5% ISGS solution has specific gravity of 1.05 to 1.10 Most visual evidence of reagent along clay “aquitard” at ca. 28 ft bgs However, ISGS reagents found its way through clay suggesting preferential pathway created by creosote
RESULTS - NAPL Monitoring Wells
No measurable free-phase NAPL in any of the monitoring wells.
Monitoring Well Pre-Injection Post-Injection NISBS- 1 NAPL stain NISBS-2 NAPL stain TIP-3 ND ND TIP-4 ND ND UGH Recovery NAPL No NAPL
Total PAH Concentrations in Soil
6 cores (3 sections) before treatment
6 cores (2 depths) after treatment
DIP area: 11% reduction
TIP area: 50% reduction
Best matched cores: dropped from 7,250 mg/kg to 3,600 mg/kg
PAH concentrations in soil reduced by up to 50% within 3 months.
PAH Concentrations in Soil Leachate
6 cores (3 sections) before treatment
6 cores (2 depths) after treatment
DIP area: 71% reduction
TIP area: 98% reduction
Best matched cores: dropped from 11,700 mg/L to 560 mg/L
PAH leachate concentrations dropped by up to 98% reduction in within 3 months.
Field Pilot Tests Results Dolomite, AL
Woodward Coke Site Overview
Coal Tar Site
Traditional 5 point injection scheme
Fractured Bedrock / Karst Geology
Target interval 20 – 30 feet below grade
10,000 lbs ISGS @ 4.5% solution
4 Drums to 1,000 gallons of water for ~1% injection solution
Average 20 PSI injection pressure. Permitted up to 50 PSI.
Average 1,000 gallons in 1 hour 15 minutes (~13 gpm)
ISGS Injection – Dolomite, AL
ISGS Field Data – Decrease in K Values Woodward Coke Site – Dolomite, AL
•2 years post ISGS injection •1-2 log decrease in values •No NAPL in MW
ISGS Material Cost – Field Applications
Denver, CO Dolomite, AL Gainesville, FL TOD = 18 g/kg TOD = 1 g/kg TOD = 122 g/kg
Dense Alluvium Injection Wells
Fractured Karst Push-Pull
Sand/Silt Direct Push and Injection wells
1,273 m3 area 3% solutions 1,850 USG/IP 2-5 gpm (20 psi)
1,500 m3 soil area 1% solutions 20,000 USG 13 gpm (20-50 psi)
1,415 m3 soil 4.5 % solutions 620 USG/DIP 2-5 gpm (<50 psi)
Cost = $40 - 50/m3
$31 -38/yd3 Cost = $45 - 50/m3
$34 -38/yd3 Cost = $60 - 75/m3
$50 -60/yd3
ISGS Summary
• ISGS can help address DNAPL Challenges – Immobilizes DNAPL surface – Reduces near field permeability – Reduces flux of constituents into GW – Enhances natural attenuation potential of GW
ISGS - A Tool for the “NAPL Tool Box”
• Crust Longevity – Effect of change in Eh on crust weathering – Validate models – Mineralogy
• Performance Monitoring – What to monitor? – How to monitor? – In situ velocity flow sensors? – Flux reduction?
Regulatory Issues for Full-Scale Applications
• Crust longevity will be dependent on the pH and Eh at the site
• The theoretical maximum is 400 years, we have estimated crust lives of 20-40 years at sites
More soluble
Eh-pH diagram from Hem (1985)
Crust Longevity
Site COI / Environmental Setting ISGS Approach / Status Active Wood Treating Site Denver, CO Superfund Site
Phase separated creosote (PAHs) and pentachlorophenol (penta). Consolidated shallow alluvium.
KMnO4 (no catalysts; no buffer) successful bench and pilot studies completed; full-scale application completed 2004.
(Active) Wood Treating Site Gainesville Florida Superfund Site
Phase separated creosote (PAHs). Sand silt environment, 5 to 22 ft bgs.
NaMnO4 (catalyzed, buffered) completed bench-scale engineering optimization tests; Pilot-scale technology validation performed in January 2008. Full-scale application recommended as part of the final design.
Former Wood Treating Site Montgomery, AL
Phase separated creosote (PAHs) Field Scale application completed 2009. One to two orders of magnitude reduction in permeability.
Former Wood Treating Site Cape Fear, NC
Phase separated creosote (PAHs) Conceptual design completed.
Former American Creosote Works Winnfield, Louisiana
Phase separated creosote (PAHs) Engineering optimization bench work completed.
Former Wood Treating Site Sand Point, ID
Phase separated creosote (PAHs) Engineering optimization bench work completed; Field Pilot Completed Q3 2010; monitoring in progress
Former Wood Treating Site Netherlands
Phase separated creosote (PAHs) Engineering optimization bench work in progress; Field Pilot scheduled for Q2 2011
ISGS Experience
Site COI / Environmental Setting ISGS Approach / Status
Former Coke Manufacturing Site South Eastern USA
Phase separated creosote / tar (PAHs) in fractured limestone. 15,700 ft3 treated from 28 to 30 ft bgs.
NaMnO4 (catalyzed, buffered) completed bench-scale engineering optimization tests; Full-scale technology implementation completed spring 2007
Manufactured Gas Plant Dover, NJ
Phase separated coal tars; goal is to reduce COC flux and EPR.
Engineering optimization bench work completed
Manufactured Gas Plant, Indiana
Phase separated coal tars; goal is to reduce COC flux and facilitate EPR.
Engineering optimization bench work completed
Former Wood Treating Site Montgomery, AL
Phase separated creosote (PAHs)
Field Scale application completed 2009. One to two orders of magnitude reduction in permeability in Karst
Manufactured Gas Plant Ferndale Michigan
Phase separated coal tars Engineering optimization bench work completed; Pilot scheduled for Q1 2011
Fuel Terminal MASSPORT
Phase separated hydrocarbons Engineering optimization bench work completed; Field work pending
Fuel Terminals El Paso Energy
Phase separated hydrocarbons Field Pilot completed Q3 2010 – monitoring in progress
Manufactured Gas Plant New York
Phase separated coal tars Engineering optimization bench work completed; Field work pending
Manufactured Gas Plant Burlington, Iowa
Phase separated creosote (PAHs)
Engineering optimization bench work pending; Field pilot pending
ISGS Experience (continued)
Site COI / Environmental Setting ISGS Approach / Status
Former Wood Treating Site, Nashua, NH
Phase separated creosote (PAHs)
Engineering optimization bench work completed 2013. Field Pilot planned for Q1 2014
Manufactured Gas Plant New Jersey
Phase separated coal tars Full scale application completed Q3 2013; effective NAPL stabilization within 2 weeks
Fuel Terminal Philadelphia, PA
Phase separated hydrocarbons Engineering optimization bench work completed 2013. Field Pilot completed Q2 2013
Industrial Process Area, Europe
Creosote and PCBs Engineering optimization bench work planned for Q1 2014
ISGS Experience (continued)
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