Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130026, P R China.
Water Environ Res. 2013 Feb;85(2):133-40. doi: 10.2175/106143012x13560205144173.
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.
建立二维实验室砂槽以研究表面活性剂强化空气注入（SEAS）与土壤气相抽提（SVE）联合修复非水相液体（NAPL）污染场地的修复效率。在修复的初始阶段，使用常规空气注入与 SVE 联合更为合理。当大部分游离 NAPL 被去除且污染物去除率保持在较低水平时，向地下水添加表面活性剂。在强化修复过程中，较低的界面张力导致多孔介质中的残余 NAPL 略有迁移，使得下游污染物浓度略有升高。然而，污染区域并未比之前扩大。表面张力的降低导致地下水中空气饱和度增加以及空气影响区域的扩大。经过 310 小时后，初始氯苯质量的 78.7%已挥发，3.3%已迁移出砂柱，17.5%位于包气带中，0.5%仍残留在地下水中，这表明 SEAS/SVE 可有效改善 NAPL 污染场地的修复。
