Enhanced copper-based electro-Fenton process with a B-doped biochar cathode for degradation of membrane concentrated landfill leachate

Electro-Fenton technology represents a highly promising approach for treating refractory organic wastewater. However, its practical implementation is constrained by a narrow effective pH range and low H 2 O 2 production efficiency. In this study, a copper-based electro-Fenton system was constructed using a boron-doped biochar (B-BC) cathode. Material characterization and electrochemical analyses demonstrated that B doping effectively modulates the surface chemistry of the cathode, significantly enhancing H 2 O 2 generation and electron transfer efficiency. Under optimized conditions, the system maintained excellent removal performance for membrane concentrated landfill leachate (MCLL) within a near-neutral pH range (5–7). Identification of reactive oxygen species revealed that ·OH and 1 O 2 jointly dominated the oxidation process, with 1 O 2 generation being markedly promoted by B doping. Furthermore, by integrating spectroscopic techniques with chemometric analysis, the structural evolution of dissolved organic matter in MCLL during the reaction was elucidated, and the positive contribution of leachable organic components from the B-BC cathode to the degradation process was confirmed. This work provides a theoretical and experimental basis for advancing efficient, stable, and pH-tolerant electro-Fenton technology in practical wastewater treatment. However, the long-term stability of catalysts under extreme conditions requires further investigation, and the potential for industrial application also needs to be further assessed through systematic techno-economic analysis.