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

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.