Activation of persulfate by a novel magnetic CuFe2O4/Bi2O3 composite for lomefloxacin degradation

Abstract

In this paper, magnetic CuFe2O4/Bi2O3 composite was successfully fabricated by a simple sol–gel combustion method with an excellent activity in the activation of persulfate (PS) for lomefloxacin (LOM) degradation. The surface morphology and structure characterizations of CuFe2O4/Bi2O3 were carried out by X-ray diffraction, scanning electron microscope, transmission electron microscope, N2 physical adsorption/desorption and vibration magnetometer measurements. The CuFe2O4/Bi2O3 synthesized exhibited high catalytic activity and good stability, it could degrade 77.19% of LOM at the natural pH (6.08), more efficient than CuFe2O4. Subsequently, the catalytic performances of CuFe2O4/Bi2O3 during LOM degradation were studied comprehensively under different initial conditions (catalyst dosage (0.6–1.8 g/L), PS dosage (0.6–1.8 g/L), initial pH value (3.0–11.0)). Also, the main active radicals (SO4− and OH) were determined by the radical scavenging experiment, which indicated that OH had a higher contribution to remove LOM than SO4− in CuFe2O4/Bi2O3/PS system. Moreover, the mechanism of the CuFe2O4/Bi2O3/PS system for LOM degradation was further proposed and the possible degradation pathways of LOM in CuFe2O4/Bi2O3/PS system were deduced. Furthermore, activated sludge inhibition test was performed to determine the variation of toxicity of the LOM during the degradation process. In a word, the CuFe2O4/Bi2O3 catalyst has a high catalytic efficiency and a short degradation period, indicating that it was a promising catalyst towards LOM wastewater treatment, which had a great potential in environmental protection.