Evaluation of surfactant performance in in situ foam flushing for remediation of dichlorodiphenyltrichloroethane-contaminated soil

Abstract

The aim of this study was to select the appropriate surfactant for the remediation of dichlorodiphenyltrichloroethane-contaminated soil using an in situ foam-flushing technique. The research investigated the performance of the nonionic surfactants polyethylene glycol octyl phenyl ether, polysorbate, and polyoxyethylene lauryl ether, as well as the anionic surfactant sodium dodecyl sulfate, in foam static characteristics, solubility enhancement of dichlorodiphenyltrichloroethane, adsorption loss onto soil, and dichlorodiphenyltrichloroethane desorption from contaminated soil using a foam-flushing approach. Considering the above four criteria, the overall performance suggested polyethylene glycol octyl phenyl ether should be selected for the remediation of dichlorodiphenyltrichloroethane-contaminated soil due to its better foamability and stability, relatively high solubilization ability for dichlorodiphenyltrichloroethane, and greatest contaminant desorption efficiency from soil via foam flushing. Results of the dichlorodiphenyltrichloroethane desorption experiments showed that desorption efficiency of dichlorodiphenyltrichloroethane by different surfactants was largely influenced by foam static characteristics and solubility enhancement of dichlorodiphenyltrichloroethane rather than adsorption loss onto soil, which indicated that foam static characteristics and solubilization ability of surfactants were two key criteria for selection of high-performance foam surfactant.