Expanding the Application of Boron-Doped Modified Diamond Electrodes in the Treatment of Recalcitrant Organic Pollutants

Wastewater from textile, leather, pharmaceutical, and chemical industries contains high concentrations of recalcitrant organic pollutants, which are difficult to mineralize completely using conventional biological or chemical processes and pose persistent ecological risks. Boron-doped diamond (BDD) electrodes, with a wide electrochemical potential window, high oxygen evolution overpotential, strong hydroxyl radical generation ability, and excellent chemical stability, provide an effective electric-field-driven route for advanced oxidation treatment. This paper systematically reviews the preparation processes, structural optimization, and electrochemical performance of BDD electrodes, and analyzes the roles of boron doping, substrate selection, surface termination, and functional modification in regulating conductivity, interfacial activity, and long-term stability. The degradation mechanism of recalcitrant organics is discussed from the perspectives of quasi-free hydroxyl radical oxidation, direct electron transfer, adsorption-controlled interfacial reactions, and mineralization pathways. Potential applications in textile dyeing wastewater, pharmaceutical wastewater, emerging pollutant degradation, and wastewater reuse are further examined. In addition, the synergistic coupling of BDD electrochemical oxidation with biological treatment, membrane separation, photocatalysis, and ultrasonic enhancement is evaluated for improving mass transfer, energy efficiency, and process stability. The analysis shows that BDD electrodes have strong engineering potential for high-COD and chromatic industrial wastewater treatment, while future scale-up requires lower-cost electrode fabrication, optimized flow-field design, and intelligent control of electrochemical parameters.