A triple-cathode electron-Fenton system for efficient Fe2+ regeneration and in-situ H2O2 electro-activation

Electro-Fenton (EF) has shown great advantages in the effecient degradation of recalcitrant organic pollutants through in situ generation of •OH, and the main limitations on system performance are the efficiencies of H 2 O 2 activation and Fe 2+ regeneration. In this research, a triple-cathode EF system with a microbial fuel cell (MFC) cathode for the acceleration of Fe 2+ regeneration, a gas diffusion electrode for H 2 O 2 production and a stainless steel mesh (SSM) for electro-activation of H 2 O 2 was designed for efficient degradation of organic pollutants. The triple-cathode EF exhibited improved removal rate for recalcitrant organic pollutants with an average electricity consumption of 18.2 kWh Kg −1 TOC for Rhodamine B degradation, and the dosage of Fe 2+ could be reduced to 0.1 mM due to better utilization of H 2 O 2 and inhibition of parasitic reactions. Electrochemical characterization and theoretical calculation revealed that both one-electron reduction and H*-mediated activation contributed to the electro-activation of H 2 O 2 on SSM. This work demonstrates a novel construction and feasible approach for efficient EF with low cost.