Field demonstration of pervaporation for the separation of volatile organic compounds from a surfactant-based soil remediation fluid

As part of a Department of Defense project, the US Environmental Protection Agency was responsible for designing, building and field operating a pilot -scale pervaporation unit. The field site was an active dry cleaning facili ty on the grounds of Marine Corps Base Camp Lejeune in Jacksonville, NC. Th e overall goal of the project was to remove tetrachloroethylene (PCE) from the soil beneath the dry cleaning shop using a surfactant-based soil remedi ation fluid and to recycle/reuse the surfactant. In order to reinject the r ecovered surfactant, the pervaporation unit was required to achieve an aver age 95% removal of contaminants from the extracted fluid over the duration of the test period. PCE removal averaged 95.8% during peak surfactant level s and exceeded 99.9% in the absence of surfactant, thereby meeting the rein jection requirement. Removal of a group of secondary contaminants at the si te, termed Varsol(TM) compounds, was monitored via concentrations of three Varsol(TM) marker compounds: decane, undecane and 1,3,5-trimethylbenzene. T he pervaporation system processed 100,000 gal of groundwater and surfactant solution over a period of 70 days. In order to evaluate and validate proce ss performance, a variety of process variables and properties were monitore d over the course of the demonstration. Pervaporation costs are projected t o be on the order of $20 per 1000 gal of surfactant solution treated for a moderate size system (10 gpm). Published by Elsevier Science B.V.