Catalytic peroxide and ozone co-oxidation of m-cresol by Fe-Mn/γ-Al 2 O 3

Abstract

In order to improve the degradation efficiency of ozone oxidation for refractory organic pollutants, a method of introducing H2O2 into the catalytic ozone oxidation system is uesd to establish a catalytic O3-H2O2 combined oxidation system, so that O3 and H2O2 have a synergistic effect in the system. A type of Fe-Mn/γ-Al2O3 catalyst which was selected because of the high catalytic performance was prepared by incipient impregnation method, and was applied in the O3/Fe-Mn/γ-Al2O3/H2O2 composite system to catalytic co-oxidation of m-cresol simulated wastewater. Scanning electron microscope (SEM), physical adsorption, X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), X-ray photoelectron spectroscopy (XPS) were used to determine the physical and chemical characteristics of the catalyst. The effect of catalytic O3-H2O2 oxidation with Fe-Mn/γ-Al2O3 were investigated, namely O3 dosage, H2O2 dosage, initial pH and space velocity. The intermediate types and molecular weight of products from the m-cresol catalytic oxidation degradation process by Fe-Mn/γ-Al2O3 were also analyzed using GC-MS and LC-OCD. The result by optimized experimental analysis shows that when Fe-Mn/γ-Al2O3 is selected as the catalyst, the highest m-cresol conversion rate of 100% and the highest TOC removal of 68.37% were obtained with the O3 dosage of 481 mg·L−1 of water and H2O2 dosage of 211 mg·L−1 water when the concentration of m-cresol was 100 mg·L−1, reaction time is 10 min, space velocity is 6 h−1 and initial pH is 6.7. The results of this study provide a reference for the combination of two technologies to degrade coal chemical wastewater.