Cd污染土壤的电动修复及其强化

为了提高电动修复镉污染土壤的效率，通过配制镉污染土壤，搭建电动修复实验装置，研究电场强度、电解液种类和添加膨润土对电动修复镉污染土壤中总Cd去除率的影响。结果表明，电动修复时间120 h，电场强度从2.5 V·cm-1增加至3 V·cm-1时，总Cd去除率增加10.62%，电场强度从3 V·cm-1增加到3.5 V·cm-1时，去除率增加1.87%；与柠檬酸为电解液对比，乙酸的总Cd去除率增加12.14%，总耗能增加62.13%，盐酸的总Cd去除率增加18.04%，总耗能增加了187.9%；乙酸为电解液，阴阳两极电解液循环与不循环相比总Cd去除率增加25.48%，能耗增加13.69%；在靠近阴极、中部及靠近阳极土壤中添加膨润土墙，总Cd去除率分别上升20.89%、18.22%、10.67%，能耗分别降低11.00%、13.43%、13.73%。循环电解液能有效减缓电阻极化和浓差极化现象并提高总镉去除率。电动修复联合膨润土吸附，能提高土壤中的总镉去除率，同时降低能耗。

Electrokinetic remediation of Cd contaminated soil and its reinforcement measures

In order to improve the efficiency of electrokinetic remediation of cadmium contaminated soil, the effects of the electric field intensity, the type of electrolyte and the addition of bentonite on the total Cd removal rate were studied through the preparation of cadmium contaminated soil and an electrokinetic remediation experimental device. The results show that the best time for electrokinetic remediation is 120 h and when the intensity of electric field increased from 2.5 V·cm-1to 3 V·cm-1, the total Cd removal rate increased by 10.62%. When the intensity of electric field increased from 3 V·cm-1 to 3.5 V·cm-1, the removal rate increased by 1.87% .Compared with citric acid for electrolyte, when acetic acid was used as electrolyte, the total cadmium removal rate increased by 12.14% and the total energy consumption increased by 62.13% .When hydrochloric acid was used as electrolyte, the removal rate increased by 18.04% and the total energy consumption increased by 187.9%. The total Cd removal rate of acetic acid for electrolyte and the cycle of electrolyte was 25.48% higher than that of the non-cyclic model, although the former has 13.69% increase in energy consumption. Adding bentonite walls to the cathode, middle and near anode soil, the total Cd removal rate increased by 20.89 %, 18.22% and 10.67%，respectively. The energy consumption decreased by 11.00%, 13.43% and 13.73%，respectively. Cyclic electrolyte can effectively reduce the polarization of resistance and the concentration polarization phenomenon. Cyclic electrolyte is very effective in improving the total cadmium removal rate. Electrokinetic remediation combined with bentonite can improve the total removal rate of cadmium in the soil and reduce energy consumption.