水和土壤环境非水溶相污染物的表面活性剂增效修复机制

Surfactant Enhanced Remediation Mechanism of NAPLs-Contaminated Soil and Groundwater

分析了表面活性剂和非水溶相有机污染物在水和土壤环境中的相互作用,以及表面活性的特性,解释了表面活性剂增效修复水和土壤环境中非水溶相污染物的机制。表面活性剂溶液通过增溶作用和增流作用,驱除地下水含水层中的非水相液体以及吸附于土壤颗粒物上的污染物,提高地下水和土壤中憎水性有机污染物的现场修复速率。增效修复效果依赖于临界胶束浓度(CMC)、污染物和表面活性剂的吸附特性、污染物的溶解性和土壤类型等。表面活性剂能增加化合物的溶解度,降低与水的界面张力,并形成乳液。

The interaction of surfactants with NAPLs in soil and groundwater are reviewed. The properties of surfactants are analyzed to explain the mechanism of surfactant-enhanced remediation of NAPLs-contaminated soil and groundwater. The technology of surfactant enhanced remediation can enhance the removal rate of hydrophobic organic pollutants from soil and groundwater. Surfactants are used to remove NAPLs from aquifers and pollutants sorbed on to the soil by solubilization and mobilization. They are successfully applied to aquifer remediation and soil decontaminations. At various concentrations, surfactants exert different effects on the biodegradation of organic pollutants. The efficiency of enhanced remediation depends on the critical micelle concentration(CMC), pollutants, adsorption properties of surfactant, solubility of pollutants and soil type. The most important parameter of mobilization is the CMC. Only when micelles are present does significant desorption of such pollutants from the soil surface occur. Under some conditions, usually at concentrations well below the CMC, the presence of surfactants can form hemimicelles and enhance the adsorption of NAPLs to the soil. Surfactants increase compounds'solubility, lower the isterfacial tension between them and water, and spontaneously form emulsions.