Insight into the performance and mechanism of magnetic Ni0.5Cu0.5Fe2O4 in activating peroxydisulfate for ciprofloxacin degradation

Magnetic nickel-copper ferrite (Ni x Cu y Fe 2 O 4 ) nano-catalyst was synthesized by co-precipitation method, and it exhibited excellent ability for activating peroxydisulfate (PDS) in the degradation of ciprofloxacin (CIP). As-prepared Ni 0.5 Cu 0.5 Fe 2 O 4 properties were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope equipped with an energy-dispersive X-ray (SEM-EDX), transmissions electron microscopy (TEM), N 2 adsorption-desorption isotherm plot of Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH), vibrating sample magnetometer (VSM). The maximum degradation efficiency is 80.2% by using 0.500 g/L of Ni 0.5 Cu 0.5 Fe 2 O 4 for activating 5.00 mmol/L of PDS to degrade CIP (20.0 mg/L) at 25 ± 2 °C for 50 min (pH = 6.00). The presence of interfering ions Cl − , NO 3 − , and HCO 3 − inhibited the reaction by producing reactive species with low oxidation potential, inducing the degradation efficiency down to 60.0%, 58.1% and 21.5% respectively. Ni 0.5 Cu 0.5 Fe 2 O 4 displayed great magnetic separation characteristic for the satisfactory magnetization; saturation value is ∼8.6 emu/g. The degradation efficiency of recycled samples has no significant difference after using three times, which is about 60%, indicating that Ni 0.5 Cu 0.5 Fe 2 O 4 is a reusability catalyst in activating PDS for CIP degradation. This work might provide an efficient and promising approach to construct recyclable magnetic materials that can be used for wastewater treatment. Magnetic nano-catalyst was synthesized via co-precipitation. Ni 0.5 Cu 0.5 Fe 2 O 4 displayed excellent ability in activating peroxydisulfate. Ni 0.5 Cu 0.5 Fe 2 O 4 displayed great magnetic separation characteristic. Ni 0.5 Cu 0.5 Fe 2 O 4 is a reusability catalyst in activating PDS for CIP degradation.