title: Remediation of nonaqueous phase liquid polluted sites using surfactant-enhanced air sparging and soil vapor extraction.
abstract: A two-dimensional laboratory sand tank was installed to study the remediation efficiency of surfactant-enhanced air sparging (-SEAS) coupled with soil vapor extraction (SVE) in nonaqueous phase liquid (NAPL) polluted sites. During initial stages of remediation, it was more reasonable to use conventional air sparging coupled with SVE. When most free NAPLs were removed and contaminant removal rate was maintained at a relatively low level, surfactant was added to the groundwater. During enhanced remediation, lower interfacial tension caused residual NAPLs in the porous media to slightly migrate, making the downstream contaminant concentration somewhat higher. The polluted area, however, was not more enlarged than before. The decrease in surface tension resulted in increased air saturation in the groundwater and the extent of the air influence zone. After 310 hours, 78.7% of the initial chlorobenzene mass had volatilized, 3.3% had migrated out of the sand profile, 17.5% was in the vadose zone, and 0.5% remained in the groundwater, thus revealing that SEAS/SVE can effectively improve the remediation of NAPL polluted sites.
authors.affiliation: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130026, P R China. qincyu@jlu.edu.cn
authors.forename: Chuan-Yu
authors.initials: CY
authors.lastname: Qin
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Zhao
authors.forename: Yan
authors.initials: Y
authors.lastname: Su
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
mesh_terms: D002722:Chlorobenzenes / Q000032:analysis; D052918:Environmental Restoration and Remediation / Q000379:methods*; D060587:Groundwater / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013500:Surface Tension; D013501:Surface-Active Agents; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D002722:Chlorobenzenes; D012989:Soil Pollutants; D013501:Surface-Active Agents; C031294:chlorobenzene