Degradation of enrofloxacin in water by Fe3O4@TiO2 magnetic photocatalyst: optimization of environmental factors

In recent years, water pollution caused by antibiotics, contaminants of emerging concern, is a hot issue that attracts much attention. In this study, TiO2 prepared by the sol-gel method was impregnated on a Fe3O4 ferromagnetic core to form a core-shell composite of Fe3O4@TiO2 magnetic photocatalyst. The material properties were determined using scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating sample magnetometry, X-ray diffraction, Raman, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller, and UV-Visible diffuse reflectance spectroscopy techniques. The photocatalytic activity and recoverability of the Fe3O4@TiO2 magnetic material were evaluated via its performance for enrofloxacin (ENR) degradation in water. The effects of various factors (e.g., pH, catalyst dosage, ENR concentration, and treatment time) on ENR degradation were investigated. Design-Expert software was then used for the experimental design and optimization of the ENR degradation. Results showed that the ENR degradation efficiency after 2.5 h was over 90% under UVA irradiation, at pH 7, catalyst dose of 0.972 g/L, and initial ENR concentration of 19.628 mg/L. After treatment, 62% of the material was recoverable by an external magnetic field, suggesting a potential solution for the treatment of antibiotics in water with high degradation efficiency and material recovery.