电动力修复铅镉复合污染土壤

采用电动力修复技术处理Pb、Cd复合污染土壤,考察了柠檬酸和乙二胺四乙酸二钠(EDTA)作为电解液对棕壤(ZR)和红壤(HR)两种我国典型壤质中Pb、Cd去除效果的影响。实验结果表明:在电压梯度为2 V/cm,修复时间为4 d的条件下,ZR的最佳电解液为EDTA,Pb、Cd平均去除率为13.2%和17.8%,HR的最佳电解液为柠檬酸,Pb、Cd的平均去除率为20.0%和33.8%;延长修复时间至10 d能显著提高HR中Pb、Cd的去除率,电解液为柠檬酸时Cd平均去除率达91.1%,电解液为EDTA时Pb平均去除率达63.2%,修复后土壤中Cd和Pb含量均低于建筑用地土壤污染风险筛选值。综合考虑能耗及修复效果,EDTA是高效且经济的修复电解液。

Electrokinetic remediation of lead-cadmium contaminated soil

Electrokinetic remediation technology was adopted to treat Pb and Cd combined contaminated soil.The effects of electrolytes citric acid and ethylenediaminetetraacetic acid disodium(EDTA)on removal of Cd and Pb from brown soil(ZR)and red soil(HR)were investigated.The experimental results show that:Under the conditions of voltage gradient 2 V/cm and repair time 4 d,for ZR,the best electrolyte is EDTA and the removal rate of Pb and Cd is 13.2%and 17.8%,respectively,while for HR,the best electrolyte is citric acid and the removal rate of Pb and Cd is 20.0%and 33.8%,respectively;The removal rate of Pb and Cd in HR can be significantly increased by prolong the remediation time to 10 d,the average removal rate of Cd is 91.1%when the electrolyte is citric acid,while,the average removal rate of Pb is 63.2%when the electrolyte is EDTA,and the concentration of Pb and Cd in the soil is lower than the risk screening value for soil contamination of development land.Considering power consumption and remediation effect,EDTA is an effective and economical electrolyte.