温和条件下水-异丙醇溶液中多氯联苯的催化脱氯

摘要

目的 研究温和条件下,多氯联苯(polychlorinated biphenyls,PCBs)的催化脱氯减毒方法.方法 在40 ℃常压条件下,水-异丙醇混合溶剂中,用钯/碳催化剂对多氯联苯进行催化脱氯研究.结果 催化脱氯反应4 h后,多氯联苯同类物总浓度从47 991 pg·ml-1减小到55 pg·ml-1,氯脱除率达到99.89%;有毒多氯联苯同类物的总毒性当量从979 pg TEQ/ml减小到0.40 pg TEQ/ml,毒性削减率达到99.96%.结论 尽管存在种类繁多的其他持久性组分的干扰,钯/碳催化剂对从垃圾焚烧飞灰中提取的多氯联苯的脱氯表现出很高的活性.%Objective The detoxification method of polychlorinated biphenyls (PCBs) by catalytic dechlorination was studied under mild conditions.Methods The catalytic dechlorination of PCBs was performed by a simple operation using palladium/carbon (Pd/C) catalyst in water-isopropanol mixed solution at 40 ℃ under atmospheric pressure.Results The results indicated that the total concentrations of PCBs congeners decreased from 47 991 pg·ml-1 to 55 pg·ml-1 and the dechlorination efficiency reached 99.89% after reaction for 4h.Moreover,the total toxic equivalent (TEQ) of toxic PCBs congeners was reduced from 979 pg TEQ/ml to 0.40 pg TEQ/ml with a conversion of 99.96%.Conclusion In spite of the existence of large amounts of other persistent components,the Pd/C catalyst shows higher activity for the dechlorination of PCBs extracted from municipal waste incineration fly ash.