Towards Environmental Sustainability: A Comprehensive Review of Electrochemical Methods for Remediating Heavy Metal Contamination in Soil and Water-Achievements, Challenges, and Prospects

Abstract

Heavy metal contamination of soil and water resources poses severe threats to environmental sustainability and human health. Electrochemical remediation technologies (ERT) have emerged as promising, versatile approaches for treating such contamination. This state-of-the-art review critically examines the fundamental mechanisms underpinning electrokinetic remediation (EKR) for soil and electrochemical treatment (ECT) for water, including electromigration, electroosmosis, electrophoresis, and electrolytic redox reactions at electrodes. We synthesize recent advances in their application for removing common heavy metals (e.g., Pb, Cd, Cr, As, Cu, Zn, Hg). Field-scale demonstrations and hybrid systems (e.g., coupling with permeable reactive barriers, phytoremediation, or chemical enhancement) are highlighted, showcasing enhanced efficiency and broader applicability. Despite significant progress, critical scale-up challenges persist, including energy consumption optimization, managing soil heterogeneity and groundwater flow, electrode stability and cost, secondary waste management, and regulatory acceptance. This review identifies key knowledge gaps and provides targeted recommendations for future research, emphasizing the need for integrated pilot studies, advanced electrode materials, renewable energy integration, standardized performance monitoring protocols, and techno-economic analyses to bridge the gap between laboratory success and widespread field implementation.