| Abstract
| - Ground water contamination frequently consists ofmixed chlorinated solvents [e.g., tetrachloroethylene(PCE), trichloroethylene (TCE), andtrans-1,2-dichloroethylene (DCE)]. In this research, mixturesof the food grade (edible) surfactants bis(2-ethylhexyl) sodium sulfosuccinate (AOT) and sodiummono- and dimethylnaphthalene sulfonate (SMDNS)were used in the formation of middle-phase microemulsions for mixed chlorinated solvents. Microemulsions of binary (e.g., PCE/TCE, PCE/DCE, DCE/TCE) and ternary (PCE/TCE/DCE) chlorinated solventsystems were evaluated. Several empirical correlations were used for describing and/or predictingthe phase behavior of the resulting middle-phasemicroemulsions (e.g., the ideal mixing rule or thenonidealregular mixing theory). The ideal mixing ruleprovideda good approximation for binary and ternarysystems, but experimental deviations from the predictionswere significant enough to affect the optimal surfactant system. Nonideal regular mixing theory demonstrated much better predictive capabilities thanideal mixing for the binary and ternary systems. Therecognition of nonideal mixing behavior and theresulting predictive correlations will be valuable inthe design of groundwater remediation scenarios whensurfactants are used for remediation of mixedchlorinated solvents.
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