摘要
To improve the conventional electrokinetic remediation of Pb-contaminated soil,the Pb-contaminated soil near a lead acid battery factory in the Pearl River Delta region of China was electrokinetically remedied with polarity exchange technique.The variations in Pb removal efficiency and the soil p H value with the treatment time and the exchange polarity interval were determined.It is found that the removal efficiency of Pb reaches a maximum of 87.7% when the voltage gradient is 1 V/cm and the exchange polarity interval is 48 h.This value is far higher than that obtained with conventional electrokinetic remediation（61.8%）.Additionally,the ＂focusing effect＂ which appears in the conventional electrokinetic remediation can be avoided,and thus additional chemicals are not needed for the polarity exchange technique.The mechanism of Pb electromigration behavior in soil during the treatment with the polarity exchange technique was described.
为了改进传统电动修复铅污染土壤效率,采用交换电极电动修复技术对珠江三角洲区域一铅酸电池厂附近的铅污染土壤进行修复。研究铅去除效率和土壤p H值的变化与修复时间及交换频率的关系。结果表明:当工作电压梯度为1 V/cm,交换间隔为48 h,铅去除效率最大值达到87.7%,远远大于传统固定电极方向运行模式的去除效率(61.8%)。另外,采用交换电极电动修复可以消除传统固定电极方向运行出现的"聚焦效应",而且不用添加化学试剂。讨论了交换电极技术中铅在土壤中电迁移的机理。
基金
Project(21003054)supported by the National Natural Science Foundation of China
Project(2013CXZDA013)supported by the Scientific Research Foundation of the Education Department of Guangdong Province,China
