A critical review on the recent progress in application of electro-Fenton process for decontamination of wastewater at near-neutral pH.

• A comprehensive literature survey on EF at neutral and near-neutral pH are presented. • Different supported and suspended catalysts used to widen the working pH are reviewed. • Recent advances on cathode modification methods in broadening EF pH are summarized. • Current application of chelating agents to increase the EF working pH are reported. • The prospects and challenges of EF process at neutral pH are addressed. One of the greatest engineering challenges of this century is development of new technologies for removing emerging hazardous contaminants from water sources. Electro-Fenton (EF) as one of the most promising approaches of advanced oxidation processes (AOPs) has received widespread attention for its excellent performance in the removal of recalcitrant pollutants due to generation of strong oxidizing species like hydroxyl radicals (OH). However, the practical application of classical homogeneous EF process is hampered by a narrow pH range (2–4) and production of sludge at higher pH values. The information obtained so far highlights the need to enhance the removal efficiency and reduce the reaction time of EF process under neutral pH conditions. Herein, this review summarizes efficient approaches in recent years (2017–2023) applied in EF system with the aim of overcoming the low pH implementation barrier, such as application of heterogeneous catalysts in EF process (HEF), cathode modifications, using chelating agents, and hybridizing the EF with other treatment methods, including adsorption, membrane, and photo/catalysis. These strategies can accelerate the iron cycle and Fe3+ reduction; therefore, more H 2 O 2 and OH can be generated. Promoting the H 2 O 2 utilization efficiency can provide more oxidative species, which leads to higher degradation and mineralization of contaminant. On the other hand, some strategies by preventing the Fe3+ precipitation at higher pH values help the system work in a wider pH range. In the final section, the challenges of these plans are discussed and perspectives for future research are proposed to improve the practicability and feasibility of the EF for wastewater treatment. [ABSTRACT FROM AUTHOR]