SDS原位微乳液对含水层中多氯代烃混合污染物的增溶作用

Solubility of in situ SDS microemulsion on chlorinated hydrocarbon mixed pollutants in an aquifer

为制备出适用于含水层中多种氯代烃混合污染物高效增溶的原位微乳液,利用PCE、CT、TCE和CF等混合氯代烃作为油相,选用十二烷基硫酸钠(SDS)、正丁醇以及氯化钾(KCl)的混合溶液作为微乳液前驱液,构建了原位微乳液体系,并探究了含水层温度和无机盐成分对原位微乳液增溶效果的影响,评估了原位微乳液在地下环境的适用性.结果表明,微乳液中正丁醇浓度与混合氯代烃的等效烷基碳数(EACN)存在二次函数关系,可用于混合氯代烃污染场地微乳液前驱液配方参数的确定;微乳液对氯代烃的增溶浓度可达500g/L以上,增溶能力为PCE>CT>TCE>CF;前驱液的粘度小于2cp,在地下环境中有较好的迁移性能;zeta电位为负值,不易被带负电的介质吸附;温度(10~20℃)对微乳液增溶氯代烃的影响不大,低浓度的水化学成分有利于微乳液增溶氯代烃,无机盐阳离子的影响顺序表现为Ca^(2+)>Mg^(2+)>K^(+)>Na^(+).

In order to prepare an in situ microemulsion suitable for the efficient solubilization of a variety of chlorinated hydrocarbon mixed pollutants in aquifers,this study used a mixture of chlorinated hydrocarbons such as PCE,CT,TCE and CF as the organic phase,and selected a mixture of sodium dodecyl sulfate(SDS),n-butanol and potassium chloride(KCl)as the precursor solution of microemulsion to construct an in situ microemulsion system.The effect of layer temperature and inorganic salt composition on the solubilization effect of in situ microemulsion was evaluated.The experimental results show that there is a quadratic function relationship between the concentration of n-butanol in microemulsion and the equivalent alkyl carbon number(EACN)of mixed chlorinated hydrocarbons,which can be used to determine the formulation parameters of the precursor liquid of microemulsion in the contaminated site of mixed chlorinated hydrocarbons.The solubility of chlorinated hydrocarbons in microemulsion can reach more than 500g/L,and the solubilization capacity is PCE>CT>TCE>CF.The viscosity of the precursor fluid was less than 2cp,and it had good migration performance in the underground environment.zeta potential was negative,which means it is not easy to be absorbed by a negatively charged medium.Temperature(10~20°C)has little effect on the solubilization of chlorinated hydrocarbons in microemulsion.The low concentration of chemical composition in water favored the dissolution of chlorinated hydrocarbons in microemulsion,and the order of influence of inorganic salt cations is Ca^(2+)>Mg^(2+)>K^(+)>Na^(+).