Visible-light-induced peroxymonosulfate activation over ZnFe2O4 fine nanoparticles for ofloxacin degradation

Widespread overuse and misuse of antibiotics has led to unintended consequences, and it is necessary to find effective ways to remove antibiotics. In this study, a visible-light-response photocatalyst zinc ferrite (ZnFe2O4) was synthesized via a hydrothermal method. Meanwhile, the X-ray diffraction, Brunauer–Emmett–Teller, scanning electron microscope, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra analysis were applied to characterize the structure, morphology, and physicochemical properties of the ZnFe2O4. The results indicated that the ZnFe2O4 was circular granular morphology with a particle size of approximately 30–50 nm and the noticeable intergranular agglomeration. The specific surface area, pore volume, and pore diameter of the ZnFe2O4 were determined to be 126.8655 m2/g, 0.2046 cm3/g, and 64.5190 Å, respectively, representing that the ZnFe2O4 had a large specific surface area. Moreover, the enhancement of degradation efficiency of ofloxacin (OFL) by peroxymonosulfate (PMS) under the visible light (Vis) was systematically evaluated. The results exhibited that the ZnFe2O4 achieved the relatively optimum catalytic activity with 80.9% of OFL degradation efficiency in 30 min at pH 6.0 under the PMS concentration of 100 mg/L and the corresponding pseudo-first-order kinetic constant of OFL degradation was 0.0438 min–1. In addition, the effects of ZnFe2O4 dosage, PMS concentration, initial OFL concentration, solution pH, and water matrix on the OFL degradation were comprehensively investigated in the Vis/PMS/ZnFe2O4 process. Furthermore, the ZnFe2O4 exhibited excellent stability and reusability for OFL degradation. The Vis/PMS/ZnFe2O4 process would be a reliable alternative for the degradation of OFL-like antibiotics to solve the increasingly serious problem of antibiotic pollution.