A facile heterogeneous system for persulfate activation by CuFe(2)O(4) under LED light irradiation

In this study, the removal performance for rhodamine B (RB) by persulfate (PS) activated by the CuFe(2)O(4) catalyst in a heterogeneous catalytic system under LED light irradiation was investigated. The effect of vital experimental factors, including initial solution pH, CuFe(2)O(4) dosage, PS concentration, co-existing anion and initial RB concentration on the removal of RB was systematically studied. The removal of RB was in accordance with the pseudo first-order reaction kinetics. Over 96% of 20 mg L(−1) RB was removed in 60 min using 0.5 g L(−1) CuFe(2)O(4) catalyst and 0.2 mM PS at neutral pH. In addition, free radical quenching experiments and electron spin resonance (EPR) experiments were performed, which demonstrated the dominant role of sulfate radical, photogenerated holes and superoxide radical in the CuFe(2)O(4)/PS/LED system. The morphology and physicochemical properties of the catalyst were characterized by XRD, SEM-EDS, TEM, N(2) adsorption–desorption isotherm, UV-vis DRS, and XPS measurements. Moreover, 18.23% and 38.79% total organic carbon (TOC) removal efficiency was reached in 30 min and 60 min, respectively. The catalyst revealed good performance during the reusability experiments with limited iron and copper leaching. Eventually, the major intermediates in the reaction were detected by GC/MS, and the possible photocatalytic pathway for the degradation of RB in the CuFe(2)O(4)/PS/LED system was proposed. The results suggest that the CuFe(2)O(4)/PS/LED system has good application for further wastewater treatment.