The efficient degradation of carbamazepine by Cu-Fe bimetallic composite carbon derived from the waste cation exchange resins: Mechanism, ecotoxicity, and continuous flow catalysis

The Cu-Fe bimetallic composite carbon (CuFeO₂@CR) was synthesized by using the waste cation exchange resins as the carbon source to degrade carbamazepine (CBZ) by activating peroxymonulfate (PMS). Results found that 91.3 % of CBZ was degraded under the optimal condition ([PMS] = 0.2 g/L, [CuFeO₂@CR] = 0.3 g/L, T = 25℃). CuFeO₂@CR could efficiently degrade CBZ at pH 3.03–9.02 and maintain the degradation at 83.6 % in the fifth cycle. The reactive oxygen species (ROS) were SO₄^•−, •OH, and ¹O₂ with the relative contribution of 35 %, 29 %, and 36 %, respectively. DFT calculation demonstrated that CuFeO₂@CR exhibited a preferential affinity for PMS and greater transfer electrons capacity than CR. Three reaction pathways were proposed in the CuFeO₂@CR/PMS system, and the degradation could effectively reduce the toxicity into non-toxic. The continuous flow catalytic experiment indicated the promising application in the treatment of antibiotic wastewater. This work provides guidance and theoretical support for CBZ degradation mechanisms.