Integrated Electrocoagulation Strategies for Wastewater Treatment and Renewable Hydrogen Production

Electrocoagulation (EC) has emerged as an effective treatment technology capable of simultaneously removing pollutants and generating hydrogen as a valuable co-product. This review examines recent progress in EC fundamentals, electrode dissolution behavior, and key operational factors influencing contaminant removal and gas generation. Analysis of over 120 studies shows that EC achieves 75–98% chemical oxygen demand (COD) reduction, 80–99% turbidity removal, Faradaic efficiencies of 60–95%, and hydrogen yields of 80–300 L H₂ m⁻³, with energy consumption ranging from 25 to 120 kWh kg⁻¹ H₂. Despite these promising results, scalability remains hindered by electrode passivation, energy intensity, sludge formation, and lack of standardized reactor configurations. Current research needs are identified in three-dimensional (3D) electrode designs, integrated EC–advanced oxidation process (AOP) and EC–membrane systems, and sludge utilization strategies. Particular focus is placed on the potential of EC-based hydrogen recovery to enhance energy self-sufficiency and advance circular-economy practices. The findings define major research priorities to establish EC as a combined platform for advanced wastewater treatment and sustainable hydrogen production.