Study On The Effect Of Ozone Catalytic Oxidation-microbial Combined Treatment Of Sewage In Industrial Park

With the continuous expansion of the scale and quantity of industrial parks in various parts of China,the variety and composition of industrial sewage are diverse,and how to ensure the stable operation of sewage stations under complex and variable water quality conditions has become an urgent problem for industrial parks.After secondary treatment,the sewage of the industrial park still contains a variety of organic matter with complex structure,strong toxicity,and refractory degradation,which is the fundamental reason for the stable compliance of sewage in the park.In this paper,MgO-Al₂O₃/honeycomb ceramic ozone oxidation catalyst was prepared for the sewage of an industrial park dominated by the fine chemical industry in southern China,using refractory pyridine as the target,and an experiment of ozone catalytic oxidation of effluent of the industrial park was carried out.Later,a batch bioreactor（SBR）was prepared,and the SBR treatment effect was improved by adding nutrients such as carbon sources to the effluent after ozone oxidation.To facilitate engineering application and maintain a high specific surface area,honeycomb ceramic was selected as the catalyst carrier,and MgO-Al₂O₃/honeycomb ceramic catalyst was prepared by the sol-gel-ultrasonic impregnation method.First,the gamma alumina coating was loaded on the surface of the honeycomb ceramic by sol-gel method,and then the active magnesium oxide component was loaded on the gamma alumina coating by the ultrasonic impregnation method,and the MgO-Al₂O₃/honeycomb ceramic catalyst with high catalytic performance was prepared at the optimized calcination temperature of 500°C.The surface characteristics of the catalyst were characterized by BET,SEM,XRD,and XPS methods,and the results showed that the catalyst had a large specific surface area,uniform magnesium oxide loading,and the presence of magnesium oxide and alumina active ingredients.With pyridine as the target pollutant,the degradation and removal method was carried out by heterogeneous ozone catalytic oxidation,and the removal rate of pyridine at 30 min of oxidation could reach99%under the conditions of p H 10,ozone concentration of 15 mg/L and catalyst dosage of 75g/L.At the same time,the results of degradation experiments on other organic pollutants show that the catalyst has a good removal effect on refractory organic pollutants such as phenol,aniline,potassium hydrogen phthalate,and pyrimidine,and the catalyst is not selective to these pollutants.The indoor experiment of ozone catalytic oxidation was carried out on the effluent of an industrial park in southern China using MgO-Al₂O₃/honeycomb ceramic catalyst,and the COD removal rate could reach 44%,the TOC removal rate reached 60%,the total nitrogen and organic nitrogen content were reduced to a certain extent,and the biochemistry was improved.In terms of effective ozone utilization,the ozone utilization rate of the Mg-Al/honeycomb ceramic catalyst is 1.57 times that of the catalyst without the use of catalyst;the catalyst is recycled 5 times,and the removal effect is not significantly changedThe effluent after ozone catalytic oxidation was treated by the SBR reactor,and after the reactor was started,the organic matter in the sewage was gradually domesticated by adding carbon source,nitrogen source,and phosphorus source.When the COD of the effluent after all oxidation,it had a certain effect on COD and ammonia nitrogen,and the effluent was about 50mg/L.The effluent met the A standard of the first-class standard of the pollutant discharge standard of urban sewage treatment plant（GB18918-2002）.