Remediation of BTBE-contaminated groundwater using conventional air sparging and soil vapor extraction

摘要

Soil and groundwater affected with gasoline constituents, including the additive methyl tert-butyl ether (MTBE), were treated using in-situ air sparging and soil vapor extraction (IAS/SVE). The gasoline was released to the subsurface from underground storage tanks situated at two different locations at the site. Five distinct localized areas with elevated hydrocarbon concentrations were identified during site characterization. The ISA/SVE remedial approach focused on BTEX and MTBE mass reduction. An IAS/SVE well network was in-stalled at each of the treatment areas. The network originally consisted of a total of 10 sparging wells and 6 SVE wells, but early results led to an expansion of the network, effectively doubling the number of sparging and SVE wells in each source area. Approximately 60 standard cubic feet per minute (scfm) of cleam air was injected into the aquifer while an equal amount of soil vapor was extracted from the overlying vadose zone. After a year of operation, MTBE concentration at the source areas was reduced by approximately 50 percent.