Study On Fabrication And Performance In Removal Of Refractory Organic Pollutants And Alleviation Of Membrane Pollution By Ozone-CuMn₂O₄/layered Carbon Catalytic Separation Membrane Reactor

Advanced purification of secondary effluent is a major challenge for municipal wastewater treatment in China.The traditional water treatment process can not effectively remove micro pollutants.In this paper,the tubular ceramic membrane was used as the carrier and the catalytic ozonation technology was used to fabricate the catalytic ozonation membrane reactor to treat the simulated secondary effluent.By combining the advantages of membrane filtration and catalytic ozonation,it can effectively degrade micropollutants,alleviate membrane pollution and control the formation of bromate.Firstly,two-step calcination method was used to prepare for CuMn₂O₄/g-C₃N₄ and CuMn₂O₄/rGO.A series of CuMn₂O₄/g-C₃N₄ catalysts were prepared with urea as the precursor according to different mass ratio and calcination temperature.The results showed that the best preparation condition was that the mass ratio of CuMn₂O₄ to urea was 0.2:10.0.The calcination temperature was 350?.When used the optimized catalyst,the degradation rate of BP-4 was 4.37 times faster than the sole ozonation and the formation of bromate was reduced by 84.7%.Secondly,choosing ceramic membrane as the carrier,using deposition calcination method to prepare CuMn₂O₄/g-C₃N₄ catalytic ceramic membrane.It was found that the thickness,smoothness and hydrophilicity of the active layer increased with the increase of the loading times,and the optimal loading times was 2 times.Based on that,the effects of operational conditions and water quality conditions on water purification performance of CuMn₂O₄/g-C₃N₄ catalytic ozonation membrane reactor were studied.The results showed that ozone concentration and transmembrane pressure were the main factors.When the ozone concentration was 20 mg/L,the transmembrane pressure was 0.2 bar,the cross-flow velocity was 1600 m L/min,the performance was the best.The specific flux of the membrane was 0.87,compared with the blank ceramic membrane coupling ozone,the degradation rate of BP-4 increased by 68.1%and the formation of bromate was reduced by 100%.Finally,CuMn₂O₄/rGOs of different mass ratios were prepared at 350?using graphite oxide?GO?as a precursor.The results showed that the best mass ratio was 1:1.Compared with the sole ozonation,the degradation rate of BP-4 was increased by 7.60 times and the formation of bromate was reduced by100%.And CuMn₂O₄/rGO was loaded on the ceramic membrane.By changing the loading times,calcination atmosphere and calcination temperature,it was found that the best preparation conditions were loading for 2 times,calcinating in nitrogen atmosphere,and calcinating at 400?.The ozone concentration and transmembrane pressure had a significant impact on the performance of membrane reactor.When the concentration of ozone wa 20 mg/L and the transmembrane pressure was 0.2 bar,the performance was the best.At this time,the specific flux of membrane reached 0.99.Compared with the blank ceramic membrane coupling ozone,the degradation rate of BP-4 was increased by 71.0%,and the self-cleaning efficiency of catalytic membrane was 52.87%.In summary,the catalytic ozonation membrane reactor fabricated in this paper showed superior performance in the process of treating simulated secondary effluent,which provided a reference for deep purification of actual secondary effluent,and provided a new research idea for the design and development of new membrane reactors.