STEAM ENHANCED RECOVERY OF PCB CONTAMINATED HEAVY OILS

摘要

Polychlorinated biphenyls (PCB) contaminated heavy oils were detected in near surface soils at arnscrap metal yard in eastern Massachusetts. These soils posed potential airborne health risks to on-siternworkers and nearby off-site residences. A plume of separate-phase hydraulic oil estimated to measurern125 feet by 150 feet in length and 1-foot thick was also detected on- and off-site.rnDue to the viscosity of the oil, a steam enhanced LNAPL recovery system was design, installed andrnoperated to reduce the viscosity of the oil and enhance product pumping. The system consists of 16rnsteam injection wells, two horizontal steam migration control trenches, six recovery wells installed withinrnthe two trenches, a re-infiltration gallery, and ten thermocouple-monitoring wells. Six pneumaticallyrnactuated pumps with separate product intakes, a steam boiler and feed system, compressor, equalizationrntank, oil water separator, sediment filters, carbon filters (air and water) and a remote computer monitoringrnsystem comprise the treatment system. The system was activated in June 2001 and has recovered overrn2000 gallons of PCB contaminated oil in five months of operation.