Effectiveness comparison of different solvents in organochlorine pesticide contaminated soil flushing
不同洗脱剂对有机氯农药污染场地土壤修复效果比较

A flushing investigation of sixteen kinds of solvents(dichloromethane,acetone,ethyl acetate,petroleum ether,hexane,methanol,ethanol,propanol,isopropanol,rhamnolipid,hydroxypropyl-β-cyclodextrin,sodium dodecyl sulfate,SDS,SDBS,Tween 80 and Triton 100) was conducted to select an optimum solvent for HCHs and DDTs,and chlordane and mirex-polluted soil flushing.Results showed that in HCHs and DDTs contaminated soil,ethyl acetate is the best eluent with removal efficiencies of 87.6% and 86.9% for HCHs and DDTs,respectively.The removal efficiencies of the other organic solvents ranged between 61.6% and 87% for HCHs and DDTs,but the removal efficiencies of surfactants were less than 4% for HCHs and DDTs.Organic solvents were better than surfactants in HCHs and DDTs polluted soil flushing.This phenomenon also occurred in chlordane and mirex-polluted soil.For mirex,the removal efficiencies of organic solvents were about 80% with the exception of propanol(63.5%).For chlordane,the removal efficiencies of organic solvents were more than 70% with the exceptions of petroleum ether(59.6%),hexane(49.3%) and propanol(42%).The removal efficiencies of chlordane for Tween 80,cyclodextrin,Triton X-100 and rhamnolipid were 54%,20%,12.8% and 12.2%,respectively,and the other surfactants’ were lower than 1%.And the removal efficiencies of mirex were 29.6% for Tween 80,12.4% for Triton X-100,5.7% for rhamnolipid.Therefore,it is concluded that organic solvents like ethyl acetate,acetone and ethanol,can act as better flushing solvents in organochlorine pesticide polluted soil in the light of removal efficiencies.