Remediation of Organochlorine Pesticides Contaminated Soils by Surfactants Enhanced Washing Combined with Activated Carbon Selective Adsorption

Abstract The present study investigated the removal of organochlorine pesticides (OCPs) from soils by triton X–100 (TX–100) enhanced washing coupled with activated carbon adsorption treatment of the solution. Two contaminated site soils including a silt clay contaminated with chlordene and DDTs, and a sandy loam containing chlordane and mirex were selected. Effects of varied operating parameters, including TX–100 dosage, liquid/soil ratio, extraction time on the contaminants removal were examined. For both soils, the OCP removal was clearly enhanced with the increase of TX–100 concentration and liquid/soil ratio. Meanwhile, the removal efficacy was also impacted by the soil texture and the characteristics and contents of the contaminants. Moreover, by using powdered activated carbon (PAC) as an absorbent, significant decrease of the contaminants in the extraction solutions were detected, and TX–100 could be further reused. Our investigation suggests that surfactants–enhanced washing combined with activated carbon selective adsorption would be an alternative to remediate OCPs contaminated soils.