Rapid Degradation of Carbamazepine in Wastewater Using Dielectric Barrier Discharge-Assisted Fe3⁺/Sodium Sulfite Oxidation

Abstract

The discharge of medical and domestic wastewater has resulted in increasing levels of pharmaceutical pollutants in water bodies. We combined dielectric barrier discharge (DBD) technology with an Fe3⁺/sodium sulfite oxidation system to address the limitations associated with traditional water treatment technologies in removing carbamazepine, exploring the application efficacy and mechanisms of this approach in carbamazepine degradation. Under optimized experimental conditions, our system achieved a 97% degradation efficiency for carbamazepine within 4 min, significantly outperforming both DBD and sodium sulfite standalone systems. Using response surface methodology to optimize experimental parameters, the effects of sodium sulfite concentration, pH, and Fe3⁺ concentration on degradation efficiency were assessed. Under optimal conditions, the system’s degradation efficiency was 2.5 times higher than that of individual systems. Hydroxyl and sulfate radicals contributed 65% and 85%, respectively, to carbamazepine degradation, while superoxide radicals contributed only 30%. The study demonstrated that this system effectively breaks down the molecular structure of carbamazepine. Eight primary intermediate degradation products were identified, and, as degradation progressed, the concentrations of these intermediates gradually decreased, ultimately achieving a mineralization rate exceeding 85%. This study not only provides an effective technical solution for rapidly treating recalcitrant organic pollutants in water but also offers new insights for environmental protection and the sustainable use of water resources while providing theoretical and experimental data for future related research.