Peroxymonosulfate enhanced electro-Fenton of sulfamethoxazole removal with ACF/CC@FeOCl-Cu cathode

An innovative ACF/CC@FeOCl-assisted FTEF-SR system was established. • FeOCl-Cu served as catalyst for the electro-Fenton and as a PMS activator. • The primary generated reactive oxygen species were • OH and SO 4 · − ${\text{SO}}_4^{{}^{·-}}$ . • Preferential removal of sulfamethoxazole was achieved in different water matrices. • The system exhibits good stability and energy-saving performance. Sulfamethoxazole (SMX), a representative sulfonamide antibiotic contaminant, poses significant environmental risks. Peroxymonosulfate (PMS) activation-driven electro-Fenton (EF) processes have attracted considerable attention for the removal of organic pollutants from water. In this study, a flow-through heterogeneous EF system integrated with PMS activation (FTEF-SR) was developed using a FeOCl-Cu-modified carbon cloth cathode for the efficient degradation of SMX. The FTEF-SR system exhibited broad pH adaptability and excellent recyclability. Under optimized conditions, near-complete removal of SMX (>99%) was achieved within 60 min. Meanwhile, the effects of catalyst dosage and ratio, current, PMS concentration, electrolyte type, pH, as well as initial concentration were systematically investigated. At a current density of 9 mA cm⁻ 2 and a PMS concentration of 1 mM, SMX and total organic carbon (TOC) removal reached 98.9% (30 min) and 80.2% (180 min), respectively. Moreover, the real-world water matrix and common coexisting ions did not significantly inhibit the removal efficiency of SMX, still maintaining above 92%, indicating that this coupling method was feasible in real application. Quenching experiments and electron paramagnetic resonance (EPR) tests revealed that • OH and SO 4 •– dominated the degradation of SMX in the FTEF-SR system. Overall, this work not only advances the development of efficient and sustainable wastewater purification technologies but also provides valuable mechanistic insights for the degradation of antibiotic contaminants. Download: Download high-res image (478KB) Download: Download full-size image