Catalytic wet peroxide oxidation of phenol over ZnFe2O4 nano spinel

Abstract

The catalytic wet peroxide oxidation of phenol was investigated over ZnFe2O4 nano spinels under different conditions designed by the experimental design. ZnFe2O4 nano oxide was synthesized by the sol-gel combustion method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope techniques. The mean particle size was determined to be around 80–90 nm. The experiments were designed by the Box–Behnken type of response surface methodology by considering four process variables: CH2O2 (mol L−1), ZnFe2O4 amount (g), temperature (°C), and reaction time (min). The optimum condition for the degradation of the phenol was predicted by the response surface methodology. The optimal conditions for phenol degradation were at 0.144 M, 0.156 g, 70 °C, and 300 min of peroxide concentration, catalyst amount, temperature, and reaction time, respectively. The predicted response under these conditions was 99%, whereas the experimental test of predicted condition led to 97% degradation of phenol. Pareto analysis predicted that the order of relative importance of model terms is as follows: reaction temperature (29%) > catalyst amount – reaction temperature (19%) > reaction temperature – reaction time (14%) > reaction time (10.9%) > catalyst amount (9.8%). The study revealed that zinc ferrite nano spinels could be promising for removal of pollutants by the catalytic wet peroxide oxidation process.