Removal of sulfamethoxazole and carbamazepine by Fe-Cu microelectrolysis combined with Fenton process

The removal effect and mechanism of sulfamethoxazole(SMZ) and carbamazepine(CBZ) were investigated by Fe-Cu bimetallic microelectrolysis and Fe-Cu bimetallic microelectrolysis in combination with the Fenton process. The impact of influent pH, reaction time, iron dosage and Cu-Fe mass ratio on the degradation of SMZ and CBZ by Fe-Cu bimetallic microelectrolysis were investigated, and the process conditions were optimized by response surface approach. On this basis, the effects of H2O2 dosage and Fenton reaction time on the removal of CBZ and SMZ by Fe-Cu bimetallic microelectrolysis and Fenton combined process were investigated. The results revealed that the removal rate of SMZ was close to 100% when pH was 2.61, reaction time was 69.26 min, dosage of Fe was 70.57 g/L, Cu-Fe mass ratio was 4.15∶1, whereas the removal rate of CBZ was less than 10% by Fe-Cu bimetallic microelectrolysis. Fe-Cu bimetallic microelectrolysis and Fenton combined process had a better treatment effect on CBZ in wastewater. The optimal dosage of H2O2 in Fenton process was 0.3 mL/L, and the optimal reaction time was 60 min. Under the optimal conditions, the CBZ removal rate could be significantly increased to 88.2%. Mechanism analysis confirmed that the removal of organic pollutants by the Fe-Cu bimetallic microelectrolysis methods mainly dominated by reduction, whereas the Fe-Cu bimetallic microelectrolysis and Fenton combined process was carried out by reduction followed by oxidation.