Abstract: To remediate low-permeability kaolin contaminated with heavy metals like zinc and cadmium, we developed a model test apparatus with electrokinetic geosynthetics (EKG) drainage plate as the electrode material. The study aimed to investigate the impact of potential gradient, electrification time, and moisture content on the removal rate of heavy metals during electric remediation, and on this basis, to determine the optimal experimental conditions. Under the optimal conditions, we conducted experimental studies to examine the effects of electrode materials and potential gradients on the removal efficiency of various heavy metals. Findings revealed that with increasing remediation time, heavy metal pollutants at the anode gradually decreased, while their concentration at the cathode gradually increased. Under the same experimental conditions, the removal rate of cadmium (Cd) was significantly higher than that of zinc (Zn). Moreover, a higher potential gradient resulted in a greater removal rate of Zn ions. Notably, using EKG as electrodes exhibited a more effective remediation effect on heavy metal-contaminated soil compared to graphite electrodes. This research contributes to the understanding of the effects and mechanisms of EKG remediation on heavy metal-contaminated soil, and provides important technical support for the application of EKG remediation technology.

Key words: electric geoplastic drainage board, heavy metals, potential gradient, water content, ecological environment restoration technology, kaolin