表面活性剂对土壤中多氯联苯的洗脱研究

采用实验室配置的PCBs污染土壤,以曲拉通X-100、吐温-80、SDS、SDBS 4种表面活性剂进行洗脱试验研究。结果表明:对于单一表面活性剂,SDS对污染土壤中多氯联苯的洗脱效果最好;采用1:20的固液比,进行2~3次洗脱,洗脱率可达50%以上;洗脱时间对洗脱效果影响不大;SDS—吐温-80混合表面活性剂对多氯联苯有协同增溶作用,且在土壤上的吸附损失较小,SDS和吐温-80的最佳质量比为5:5,在此条件下,浓度为7 000 mg/L的混合表面活性剂对多氯联苯污染土壤进行3次洗脱,洗脱率可高达97.89%。

Washing Polychlorinated Biphenyls from Contaminated Soils by Surfactants

Experiment was done in laboratory to wash polychlorinated biphenyls(PCBs) contaminated soil using 4 kinds of surfactants such as Triton X-100,Tween-80,sodium dodecyl sulfate(SDS) and sodium dodecylbenene sulfate(SDBS).Results showed that washing efficiency of SDS was the best in experimental conditions when single anionic surfactant was applied.The best solid-liquid ratio was 1:20,and two or three time elution was necessary to get better elution efficiency,but elution time didn’t affect elution effect obviously.Anionic-nonionic mixed surfactants not only increased the solubilization of PCBs,but also reduced the sorption onto soils.When SDS—Tween-80 mixed surfactants were applied at 7 000 mg/L,in the best mass ratio conditions of 5:5,97.89% PCBs was washed out from the laboratory contaminated soil after 3 times elution.