UV-Cu/Mn-Zeolite Heterogeneous Fenton Method for Degradation of Sulfamethoxazole

Sulfamethoxazole (SMX) and other antibiotics pose significant risks to humans and the environment even at trace concentrations, whereas conventional physicochemical and biological degradation methods are often ineffective. This study employed an integrated strategy combining photocatalysis with heterogeneous Fenton technology for SMX removal, and compared the removal efficiency of the UV-H2O2 and the UV-zeolite-supported Cu/Mn bimetallic heterogeneous Fenton method. The results demonstrate that the catalytic activity is primarily influenced by the calcination temperature, followed by the calcination time and the Cu/Mn molar ratio in the impregnation solution. The optimal catalyst is prepared with a Cu/Mn molar ratio of 2∶1 and calcined at 300 ℃ for 3 h. In the catalyst, copper and manganese exist primarily as CuO, Cu2O, Cu/Mn oxides, and MnO2/Mn3O4. At pH=7.2 and an initial SMX concentration of 20 mg/L, the optimized UV-Cu /Mn-zeolite heterogeneous Fenton system with 0.15 g/L catalyst and 7.5 mmol/L H2O2 achieved a 77.3% SMX removal rate. This represents a 15.1% improvement over the conventional UV-H2O2 process, and the degradation follows pseudo-first-order kinetics. Metal leaching remained below 0.5 mg/L after 90-min reaction, and the catalyst lost less than 5% of its initial activity after four reuse cycles.