Advances in Electrochemical Treatment of Wastewater : Process Design and Electrode Material Performance Evaluation

Electrochemical treatment technologies have emerged as promising alternatives for the efficient removal of organic pollutants, heavy metals, nutrients, and pathogens from complex wastewater streams. This review presents recent advances in the process design and performance evaluation of electrochemical systems, with a particular focus on the role of electrode material innovations. Electrochemical oxidation and reduction processes, including anodic oxidation, electro-Fenton, and electrocoagulation, offer high treatment efficiency, environmental compatibility, and minimal chemical usage. The success of these processes is largely governed by the electrode material, which influences pollutant degradation pathways, energy consumption, and system durability. Advances in electrode materials such as boron-doped diamond (BDD), titanium suboxides, carbon-based composites, and doped metal oxides have significantly improved catalytic activity, corrosion resistance, and pollutant selectivity. Process configurations, including batch, continuous flow, and integrated hybrid reactors, are discussed in terms of mass transfer efficiency, energy utilization, and scalability. Experimental studies reveal that BDD electrodes exhibit exceptional mineralization capabilities for persistent contaminants due to their high overpotential for oxygen evolution, while carbon-based electrodes offer cost-effective alternatives with tunable surface properties. Moreover, the coupling of electrochemical systems with biological or membrane-based units enhances overall treatment efficiency and reduces operational costs. Process modeling and real-time control strategies are also gaining traction, enabling optimized current density, residence time, and electrolyte concentration to improve removal efficiency and minimize by-product formation. Despite these advancements, challenges remain in terms of material cost, electrode fouling, and energy demands for large-scale deployment. Future research should focus on the development of low-cost, high-performance electrode materials, modular reactor designs, and renewable energy integration. This review concludes that electrochemical treatment systems, underpinned by strategic electrode engineering and process optimization, hold great promise for sustainable wastewater management across industrial and municipal applications.