Study On The Treatment Of Dairy Farming Wastewater By Ozone Heterogeneous Catalytic Moderate Oxidation Technology

Livestock and poultry breeding wastewater contains high concentration of organic matter ammonia nitrogen and suspended solids and a considerable number of pathogens and specific structure of substances.After aerobic treatment,the colourity also increases sharply,which is the main pollution source of surface water and groundwater.At present,many researchers think that the treatment of livestock and poultry breeding wastewater is a difficult problem and pay great attention to it.The traditional technologies to treat livestock and poultry breeding wastewater mainly include field returning technology,ecological restoration technology and biochemical treatment technology,but the removal efficiency of polycyclic organic compounds is not ideal to the polycyclic organism.Due to its complex molecular structure and stable chemical properties,traditional methods are unable to do anything about it,so the COD_Cr and colourity of effluent after treatment remain high.Therefore,the establishment of different regional aquaculture wastewater treatment model according to local and water conditions has become the focus of current research.The Mn-Fe-Ce/γ-Al₂O₃ catalyst was prepared byγ-Al₂O₃ with the optimized preparation method of impregnation-calcination,and its properties were characterized.The SEM-EDX,XRF,XRD,BET and XPS results showed that the modified Mn-Fe-Ce/γ-Al₂O₃ternary catalyst has an excellent catalytic performance,the introduction of Mn,Fe and Ce promote the formation of abundant oxygen defects on the catalyst surface,which is assumed to be responsible for HO·generation.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,p H and catalyst dosage on COD_Cr and the colourity removal ratio were investigated.The results show that the optimum treatment conditions were a reaction time of 20 min,p H 9,and catalyst dosage of 15 g·L^-1.The COD_Cr removal ratio reached 48.9%and the colourity was 95%under the optimum conditions.BOD₅/COD_Cr increased from 0.21 to 0.54 after catalytic ozonation,indicating that the biodegradability of wastewater was significantly improved.Catalytic ozonation not only can remove COD_Cr and colourity,but also improves biodegradability effectively.It can create conditions for oxidized sewage to continue to use the biochemical methods.Further experiment to add the TBA showed that HO·plays a major role in the system.The above results provide a new technical method and theoretical guidance for the treatment of dairy farming wastewater.