Electrokinetics is an in-situ soil remediation technique by which the flow direction of the pollutants can be controlled and soil with low permeability can be treated. In this study, the remediation of cadmium (Cd) contaminated kaolin by a new-style electrokinetics using array electrodes (AEEK) coupled with permeable reactive barrier (AEEK-PRB) process was investigated and the effects were compared. Zeolite and zero-valent iron (ZVI) were used as the PRB material. The investigation firstly evaluated voltage gradients and soil moisture conditions, which ranged from 1.5-3.0 V/cm and 25%-40%, respectively. The best combination of parameters was a voltage gradient of 2.0 V/cm and a moisture content of 30%. The integration of PRB with AEEK could more effectively remove Cd from kaolin with citric acid as the electrolyte. The average removal rate reached the highest at 93.1%, when the initial Cd²⁺ concentration was 300 mg/kg. Morphological analysis of Cd before and after remediation showed AEEK-PRB could effectively remove most of the exchangeable Cd fraction and the carbonate fraction, as well as some of the organic matter-bound and Fe-Mn oxide-bound fraction, thus reducing the mobility and toxicity of Cd in soil. Cd-polluted soil remediation of AEEK-PRB was comparable to that of previously conducted electrokinetics.

电动学是原位的土壤修复技术，可控制污染物的流向并处理低渗透性土壤。在这项研究中，研究了使用阵列电极（AEEK）和可渗透反应性阻挡层（AEEK-PRB）结合的新型电动动力学对镉（Cd）污染的高岭土的修复，并比较了其效果。沸石和零价铁（ZVI）用作PRB材料。该研究首先评估了电压梯度和土壤湿度条件，分别为1.5-3.0 V / cm和25％-40％。参数的最佳组合是2.0 V / cm的电压梯度和30％的水分含量。PRB与AEEK的结合可以更有效地以柠檬酸为电解质从高岭土中去除Cd。平均去除率最高，达到93.1％，²⁺浓度为300 mg / kg。修复前后镉的形态分析表明，AEEK-PRB可以有效去除大部分可交换的Cd馏分和碳酸盐馏分，以及一些与有机物结合和Fe-Mn氧化物结合的馏分，从而降低了迁移率和镉在土壤中的毒性。AEEK-PRB的Cd污染土壤修复与以前进行的电动动力学相当。