A review of anodic oxidation, electro-Fenton and electrochemical nitrate reduction: A decade of advances and future directions

Abstract

Electrochemical water treatment has advanced considerably over the past decade and is increasingly recognized as an effective and versatile approach for the removal of organic and inorganic contaminants. This review provides an integrated assessment of progress from 2015 to 2025 in anodic oxidation, electro-Fenton, and electrochemical nitrate reduction. Advances in electrode materials, reaction mechanisms, reactor engineering, and energy performance metrics are critically evaluated, with particular emphasis on operation in realistic water matrices and the transition from batch laboratory systems to flow-based and semi-autonomous configurations. Beyond materials development, this review demonstrates that reactor configuration, operating mode, and energy management increasingly govern process stability and scalability. The role of normalized energy metrics is evaluated within an engineering framework to support meaningful performance comparison. Persistent challenges are identified, including unrealistic contaminant concentrations, electrode durability limitations, and techno-economic constraints. Finally, emerging trends toward modular, adaptative, and decentralized systems, integration with renewable energy sources, hybridization with biological and membrane processes, and selective transformation or valorization of by-products are identified as key directions for future research