Analysis of governing factors in electrokinetic remediation of Cu–Zn contaminated clay using a surface‐applied electrolyte

Abstract The advanced electrokinetic remediation (EKR) system with surface‐mounted electrolyte reservoirs prevents leakage and reduces costs, but the effects of operational parameters on Cu‐ and Zn‐contaminated soft clay remain unclear. This study conducted lab‐scale EKR experiments with varying citric acid concentrations, electrolyte volumes, contact areas, and voltage modes to evaluate remediation efficiency. Results indicate that highly contaminated soil exhibits lower binding energy, facilitating desorption and removal. For typically recalcitrant, low‐concentration contaminated soil, stepwise voltage increase with enhanced electric field intensity and prolonged duration promoted heavy metal electromigration, achieving a zinc removal rate of 83.5% and a copper removal rate of 67.0%. These findings demonstrate that optimizing key design parameters—including voltage strategy, treatment duration, electrolyte concentration, dosage, and contact area—can effectively improve overall heavy metal removal efficiency from contaminated soft clay.