Preparation of the Mn-Fe-Ce/γ-Al2O3 ternary catalyst and its catalytic performance in ozone treatment of dairy farming wastewater

Abstract

The quality of dairy farming wastewater in different regions is particular and different. In Southern China, the Chemical Oxygen Demand (CODCr) and colourity of effluent from conventional dairy farming wastewater treatment processes are similar. Catalytic ozonation is a very promising technical method. In this paper, the Mn-Fe-Ce/γ-Al2O3 catalyst was prepared via the optimized preparation method of impregnation roasting using γ-Al2O3 as the carrier, and this catalyst was used in the ozonation of actual dairy farming wastewater from treatment facilities. The performance of the Mn-Fe-Ce/γ-Al2O3 catalyst on dairy farming wastewater was investigated using a simulated dynamic test. The effects of the reaction time, pH and catalyst dosage on CODCr and the colourity removal ratio were investigated. The results show that the optimum treatment conditions were a reaction time of 20 min, pH 9, and catalyst dosage of 15 g/L. The CODCr removal ratio reached 48.9% and the colourity was 95% under the optimum conditions. BOD5/CODCr increased from 0.21 to 0.54 after catalytic ozonation, indicating that the biodegradability of wastewater was significantly improved. This research provides a new method and theoretical guidance for dairy farming wastewater treatment. Keywords: Mn-Fe-Ce/γ-Al2O3, Refractory organics, Dairy farming wastewater, Catalytic ozonation, HO·