title: Pilot-scale demonstration of surfactant-enhanced PCE solubilization at the Bachman Road site. 2. System operation and evaluation.
abstract: 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
authors.affiliation: Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: C Andrew
authors.initials: CA
authors.lastname: Ramsburg
authors.forename: Kurt D
authors.initials: KD
authors.lastname: Pennell
authors.forename: Linda M
authors.initials: LM
authors.lastname: Abriola
authors.forename: Gary
authors.initials: G
authors.lastname: Daniels
authors.forename: Chad D
authors.initials: CD
authors.lastname: Drummond
authors.forename: Matt
authors.initials: M
authors.lastname: Gamache
authors.forename: Hsin-Lan
authors.initials: HL
authors.lastname: Hsu
authors.forename: Erik A
authors.initials: EA
authors.lastname: Petrovskis
authors.forename: Klaus M
authors.initials: KM
authors.lastname: Rathfelder
authors.forename: Jodi L
authors.initials: JL
authors.lastname: Ryder
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Yavaraski
mesh_terms: 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*
chemical_list: D002273:Carcinogens; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D013750:Tetrachloroethylene