Breaking down phenylurea herbicides: advanced electrochemical approaches for environmental degradation and remediation

Abstract

Phenylurea herbicides (PUHs) represent one of the most extensively used herbicide families in agriculture worldwide. While effective for weed control, their environmental persistence, bioaccumulation potential, and formation of toxic metabolites raise significant environmental concerns. This review examines current electrochemical strategies for degrading phenylurea herbicides, with special emphasis on electrochemical oxidation (EC), photoelectrochemical processes (PEC), electro-Fenton (ECF) and photo-electro-Fenton (PECF), with particular attention to the various reactor configurations and their operational mechanisms. A critical innovation of this review lies in its systematic parameter assessment framework, which categorizes nine key operational parameters across all electrochemical degradation methods: electrode material, catalyst type, cell configuration, radiation source, operating conditions (pH, current density, temperature), removal efficiency, mineralization rate, degradation kinetics, identified intermediates, and energy consumption. For each technique, we highlight which parameters are essential, important, critical, or non-applicable, providing a structured framework to guide future experimental design. Selected case studies are presented to illustrate practical applications and performance outcomes. The review concludes with a critical analysis of current knowledge gaps and future research avenues that could enhance the sustainability, efficiency, and scalability of electrochemical remediation technologies. This work is intended as a comprehensive resource for environmental chemists, analytical scientists, and remediation engineers committed to addressing phenylurea herbicide contamination.