Facile and green synthesis of ZnFe2O4@CMC as a new magnetic nanophotocatalyst for ciprofloxacin degradation from aqueous media

As an antibacterial agent, ciprofloxacin is an antibiotic which is widely used to treat infections. It is mostly excreted in the non-metabolized form and, finally, enters water through the discharge of sewage and wastewater. The aim of this research is to synthesize ZnFe2O4@CMC and study its efficiency in the removal of CIP during the photocatalytic process. We successfully synthesized the ZnFe2O4@CMC nanobiocomposite by the hydrothermal method. The prepared photocatalyst was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscope-energy dispersive spectroscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), Brunauer-Emmett-Teller (BET) technique, UV-vis diffuse reflectance spectra (UV-DRS), energy-dispersive X-ray spectroscopy (EDS) and mapping. The photocatalytic activity of ZnFe2O4@CMC was evaluated by investigating the effect of reaction time (20-120 min), initial CIP concentration (5-30 mg/L), pH (3-11), photocatalyst dosage (0.1-0.5 g), degradation kinetic and TOC removal parameters in the removal of CIP. The optimum conditions for the maximum removal efficiency in the synthetic (87%) and real (79%) samples were pH = 7, initial CIP concentration =5 mg/L, photocatalyst =0.3 g and irradiation time =100 min. The removal efficiency of TOC by the photocatalytic process was reported 75% in the optimal condition. The kinetic studies showed that the photocatalytic degradation of CIP followed the pseudo-first order kinetic and Langmuir-Hinshelwood equation. The new magnetic ZnFe2O4@CMC nanobiocomposite demonstrated good chemical stability and reusability after five runs. This work introduced a new magnetic nanocomposite and also provided a new idea for the removal of antibiotics from aqueous media. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.