Fered-Fenton enhanced boron-doped diamond electrochemical oxidation for wastewater treatment: Antibiotic degradation, kinetics, and environmental effects

Many conventional wastewater treatment plants exhibit insufficient removal of antibiotics. Thus, this study used electrochemical oxidation with boron-doped diamond electrodes and Fered-Fenton processes to design an integrated system for antibiotic degradation. Response surface methodology identified the optimal conditions for H 2 O 2 , FeSO 4 , FeCl 3 , Na 2 SO 4 , and pH as 0.704 mM, 2.598 mM, 0.781 mM, 98.772 mM, and 4.057, respectively. Unlike traditional advanced oxidation processes, the developed system saved energy by avoiding high chemical concentrations and light sources. The BDD electrodes enhanced electron transfer, had a high oxygen evolution potential, and facilitated in situ H 2 O 2 generation at the cathode, while its integration with Fered-Fenton processes maintained the Fe 2+ /Fe 3+ regeneration, thereby continually supplying reagents to the solution. These synergistic reactions resulted in substantial production of reactive oxygen species (ROS) such as OH, SO 4 – , and O 2 – , which ultimately formed 1 O 2 , responsible for the effective degradation of sulfamethoxazole and other antibiotics. We confirmed this persistence of ROS using scavenging experiments and electron spinning resonance. The treated water had minimal phytotoxicity on Solanum lycopersicum L. and Brassica oleracea var. capitata f. rubra microgreens at concentrations of ≤30 %, while higher levels modestly impeded root and shoot growth. Cytotoxicity tests on REM134 and ELT3 showed that sulfamethoxazole-contaminated water significantly induced cell death, whereas the treated water affected cells only at concentrations of >30 %. This integrated strategy eliminated antibiotics, reduced environmental concerns, and showed potential for enhanced wastewater treatment. • Fered-Fenton greatly enhances the efficiency of BDD electrochemical oxidation. • RSM optimized the EBFF system using five key independent variables. • In the EBFF, Fe 3+ auto-conversion to Fe 2+ with H 2 O 2 is key to boosting ROS generation. • 1 O 2 , the final ROS attacking SMX, is crucial to the EBFF system's efficiency. • Treated water <30 % is safe for ELT3, REM134 cells, tomatoes and microgreens.