Study On The Fabrication And Catalytic Degradation Performance Of High Efficiency Oil/Water Separation Membranes

The discharge of industrial oily wastewater and frequent oil leakage accidents not only severely damage the ecological environment,but also affect human normal life.Traditional oil/water separation methods such as centrifugation,combustion,and chemical oxidation not only have the disadvantages of low separation efficiency and high maintenance costs,but some separation methods can also cause secondary pollution.In recent years,studies have found that superwetting separation materials can realize oil/water separation economically and efficiently,and have broad industrial application prospects.However,most oil/water separation materials cannot effectively remove organic pollutants in wastewater,which limits their application in engineering practice.In response to this problem,this paper prepared a micro-scale porous mesh membrane attached to TiO₂and Cu O through the dip-coating method and the immersion-burning method,which can not only achieve the purpose of efficient oil/water separation,but also realize the catalytic degradation of rhodamine B and methylene blue.And it provides new ideas for simultaneous oil/water separation and catalytic degradation.The main research contents and results of the thesis are as follows:（1）Through the dip-coating method,a micro-scale porous mesh membrane attached with TiO2 was constructed,which realized the efficient separation of oil/water mixture and the photocatalytic degradation of Rhodamine B.The experimental results show that the treated membrane has good superhydrophilicity and underwater superoleophobicity.For several different oil/water mixtures,the separation efficiency has reached more than 99.5%,and the separation efficiency and water flux are still maintained at 99%and 2000 L m^-2h^-1after 10cycles of use.The experimental results of photocatalytic degradation of rhodamine B show that the prepared membrane can achieve nearly 100%catalytic degradation efficiency within250 min.Analysis of the mechanism of photocatalytic degradation of rhodamine B by membrane showed that oxidizing substances produced by TiO₂photocatalysis can oxidatively degrade rhodamine B.（2）In order to further achieve the purpose of combining oil/water separation and catalytic degradation,the Cu O attached micro-scale porous mesh membrane was constructed through the immersion-burning method to realize the synchronization of oil/water separation and catalytic degradation.The wettability experiment shows that the concentration of the solution has little effect on the wettability of the membrane.The membrane treated with different concentrations all showed good wettability,and the water contact angle was 0°,while the underwater oil contact angle can reach 155°.In this experiment,compared with other membranes,the membrane treated with 5%concentration solution has better catalytic degradation performance.After 10 cycles of oil/water separation tests,the separation efficiency of the membrane was still maintained at 99%,while its water flux was also maintained at about 11000 L m^-2h^-1,which proves that the membrane has good recyclability.By controlling the flow rate of the oil/water mixture,the goal of simultaneous oil/water separation and catalytic degradation of methylene blue and rhodamine B was achieved.In addition,the mechanism of catalytic degradation was analyzed,and it was proved that the degradation of organic dyes was mainly caused by the oxidation of strong oxides produced by Cu O catalyzed peroxymonosulfate.Through the above experimental research,the possibility of simultaneous oil/water separation and catalytic degradation has been proved,which provides an experimental and theoretical basis for its application in engineering practice.