Pilot-scale demonstration of surfactant-enhanced PCE solubilization at the Bachman Road site. 2. System operation and evaluation.
A pilot-scale demonstration of surfactant-enhanced aquifer remediation (SEAR) was conducted during the summer of 2000 at the Bachman Road site in Oscoda, MI. Part two of this two-part paper describes results from partitioning and nonpartitioning tracer tests, SEAR operations, and post-treatment monitoring. For this field test, 68 400 L of an aqueous solution of 6% (wt) Tween 80 were injected to recover tetrachloroethene-nonaqueous phase liquid (PCE-DNAPL) from a shallow, unconfined aquifer. Results of a nonreactive tracer test, conducted prior to introducing the surfactant solution, demonstrate target zone sweep and hydraulic control, confirming design-phase model predictions. Partitioning tracer test results suggest PCE-DNAPL saturations of up to 0.74% within the pilot-scale treatment zone, consistent with soil core data collected during site characterization. Analyses of effluent samples taken from the extraction well during SEAR operations indicate that a total of 19 L of PCE and 95% of the injected surfactant were recovered. Post-treatment monitoring indicated that PCE concentrations at many locations within the treated zone were reduced by as much as 2 orders of magnitude from pre-SEAR levels and had not rebounded 450 days after SEAR operations ceased. Pilot-scale costs ($365 900) compare favorably with design-phase cost estimates, with approximately 10% of total costs attributable to the intense sampling density and frequency. Results of this pilot-scale test indicate that careful design and implementation of SEAR can result in effective DNAPL mass removal and a substantial reduction in aqueous concentrations within the treated source zone under favorable geologic conditions
Ramsburg
C Andrew
CA
Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts 02155, USA.
Pennell
Kurt D
KD
Abriola
Linda M
LM
Daniels
Gary
G
Drummond
Chad D
CD
Gamache
Matt
M
Hsu
Hsin-Lan
HL
Petrovskis
Erik A
EA
Rathfelder
Klaus M
KM
Ryder
Jodi L
JL
Yavaraski
Thomas P
TP
D002273:Carcinogens / Q000737:chemistry*; D005544:Forecasting; D008962:Models, Theoretical; D012989:Soil Pollutants / Q000302:isolation & purification*; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*; D013750:Tetrachloroethylene / Q000737:chemistry*; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D002273:Carcinogens; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D013750:Tetrachloroethylene