Research progress on remediation of heavy metal contaminated soil by electrokinetic-permeable reactive barrier

In the past two decades, electrokinetic technology combined with permeable reactive barriers (EK-PRBs) has demonstrated great potential for soil heavy metal remediation. This review focuses on outlining the strategies for improving the removal efficiency of heavy metal by EK-PRB. Adjusting the type of electrolyte, electrode material, type and position of PRB material, magnitude of the electric field, soil water content and pH are the key factors. We have summarized and concluded the optimization methods of EK-PRB energy consumption for the first time. We found that regulating the electric field and self-powered cells have great potential for energy consumption optimization in the future. The existing EK-PRB remediation technologies were summarized and prospected, providing a comprehensive and systematic knowledge framework for EK-PRB remediation of soil heavy metal pollution. EK-PRB technology still needs to be explored in the direction of optimizing energy consumption and PRB material development, and more basic research is still needed to collect data for predictive system design. This review would suggest valuable views for practical remediation of heavy metals in soil by EK-PRB with high efficiency and acceptable energy consumption.