Electrokinetic Remediation of Zn-Polluted Soft Clay Using a Novel Electrolyte Chamber Configuration

This study investigated a novel electrolyte chamber configuration for heavy-metal-contaminated fine-grained soil to reduce the leakage of electrolyte solution and alleviate secondary pollution, finally promoting the electrokinetic remediation (EKR) potential to be scaled up for application. Experiments were conducted on clay spiked with Zn to investigate the feasibility of the novel EKR configuration and the effect of different electrolyte compositions on the electrokinetic remedial efficiency. The results show that the electrolyte chamber situated above the soil surface is promising for the remediation of Zn-contaminated soft clay. Using 0.2 M citric acid as the anolytes and catholytes was an excellent choice for pH control in the soil and the electrolytes. Through this, the removal efficiency in different soil sections was relatively uniform and more than 90% of the initial Zn was removed. The supplementing of electrolytes resulted in the water content in the soil being distributed evenly and finally sustained at approximately 43%. Consequently, this study proved that the novel EKR configuration is suitable for fine-grained soil contaminated with Zn.