Catalytic wet peroxide oxidation of metronidazole over Fe and Mn supported UiO-66 catalysts: Kinetic study

Abstract

The metronidazole (MNZ) antibiotic is widely used to treat infections caused by anaerobic bacteria and it is difficult to biodegrade in the pharmaceutical wastewaters. In this study, Fe-UiO-66, Mn-UiO-66 and Fe/Mn-UiO-66 catalysts were prepared for the kinetic study of catalytic wet peroxide oxidation (CWPO) degradation of metronidazole in pharmaceutical wastewater. The catalysts were characterized by XRD, FT-IR, N2 adsorption-desorption, SEM, and TGA. The effects of Fe and Mn loading rate, catalyst dosage, MNZ concentrations, calcined temperature of Mn-UiO-66 and Fe/Mn ratio on the CWPO of metronidazole wastewater were systematically studied. Fe-UiO-66 catalysts exhibited better catalytic activity for the CWPO degradation of metronidazole wastewater (XMNZ = 93 %, XH2O2 = 78 %) compared to Mn-UiO-66 catalysts (XMNZ = 20 %, XH2O2 = 30 %). The kinetics study indicates that the CWPO process is fitted for the pseudo-first-order reaction with activation energy of 89.37 kJ/mol and 95.08 kJ/mol obtained on the Fe-UiO-66 and 2Fe/Mn-UiO-66 catalysts, respectively. The supported Fe and Mn UiO-66 catalysts showed good catalytic activity for CWPO of metronidazole which exhibited potential application in the wastewater treatment process.