Conductivity Reduction Due to Emulsification during Surfactant Enhanced-Aquifer Remediation. 1. Emulsion Transport

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• 作者：Vivek Jain and Avery H. Demond
• 刊名：Environmental Science & Technology
• 出版年：2002
• 出版时间：December 15, 2002
• 年：2002
• 卷：36
• 期：24
• 页码：5426 - 5433
• 全文大小：214K
• 年卷期：v.36,no.24(December 15, 2002)
• ISSN：1520-5851

文摘

Surfactant-enhanced aquifer remediation (SEAR) is apromising technology for the remediation of subsurfacezones contaminated with organic liquids. To ensure thesuccess of SEAR, the potential reduction in hydraulicconductivity must be evaluated. The objective of this studywas to examine the process of conductivity reductiondue to the transport of an emulsion, generated by mixingtetrachloroethylene with 4% solutions of two nonionicsurfactants, in packed beds of sand-sized silica particles.The injection of the emulsion resulted in a 75-85%reduction in conductivity, depending on the properties ofthe surfactant and the porous medium. The greater viscosityof the emulsion relative to that of water accounted forabout 25% of the reduction. The remainder was attributedto the clogging of the porous medium by the emulsion.The relative sizes of the emulsion droplets and the packedbed's pores, coupled with measurements of zeta potentialof the emulsion droplets and silica particles, suggestedthat multilayer deposition was the principal mechanism ofclogging. This hypothesis was corroborated by directobservation of the emulsion transport process in a micromodel.To simulate the reduction in hydraulic conductivity inthese systems accurately, it was necessary to modify theemulsion transport model by Soo and Radke to includethe phenomena of viscosity variation and multilayering.