Magnetically separable MgFe2O4 nanoparticle for efficient catalytic ozonation of organic pollutants

Abstract

Magnetically separable MgFe₂O₄ was synthesized and used in catalytical ozonation of 4-chlorophenol (4-CP). The prepared catalyst was characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Brunauer−Emmett−Teller (BET) and Vibrating-Sample Magnetometer (VSM). The optimum conditions for the highest efficacy of the catalytic ozonation process were found to be pH 7, catalyst dose 0.2 g/L, O₃ concentration 1.67 mg/L.min, contact time of 30 min and 4-CP concentration 100 mg/L. At these optimal conditions, the efficiency of process was 93.5%. In addition, the results showed that the catalyst can significantly enhance the mineralization of 4-CP, and more than 70% 4-CP were mineralized in the presence of the catalyst, that is almost 2.5 times higher than ozonation alone. Moreover, the results revealed that the removal efficiency was not affected by solution pH and removal efficiency in the O₃/MgFe₂O₄ process exceeded 90% over a wide pH range of 4–10. This study demonstrates that MgFe₂O₄ is a recyclable and efficient catalyst in the ozonation organic pollutants.