Preparation And Performance Research Of ?-Al₂O₃/CoFe₂O₄ Composite Ceramic Membrane For Catalytic And Separation Of Methyl Blue And Ibuprofen

Ceramic membrane has great application potential in water treatment,which mainly comes from its advantages of high mechanical strength,anti physic-chemistry corrosion,and longer life time.However,it exists membrane fouling,single separate function and high energy consumption problems.In response to these problems mentioned above,we prepared one gravity driven ?-Al₂O₃/CoFe₂O₄ composite ceramic membrane which had catalytic and separation functions at the same time.The specific research contents as follows: 1)According to the method of wet-spinning combined with phase inversion and dip-coating,we prepared substrate ceramic membrane and ?-Al₂O₃/CoFe₂O₄ composite ceramic membrane,respectively,and conducted a series characterization;2)In order to explore the composite ceramic membrane coupling technology application advantages in water treatment,we chosen methyl blue and ibuprofen as the moderate pollutants and explored its catalytic and separation performance in water treatment after coupled with sulfate radical advanced oxidation processes.The main results and conclusions obtained as follows:1 Membrane preparation and characterization.For the substrate ceramic membrane,with the increasing of wet-spinning parameters of air gap and nitrogen pressure,the sponge layer became thinner and the average pore size turned into large.XRD results showed that the catalyst could be turned into CoFe₂O₄ phase under 300 oC,400oC and 500 oC three calcination temperatures.For the composite ceramic membrane,the optimum preparation conditions were 15 s dipping time,coating twice,and the loading amount of catalyst was about 0.86 ± 0.04mg/cm.After modified,the physical and chemistry characteristics of isoelectric point,water contact angle and surface hydroxyl concentration had changed,which meant that material composition on the surface of membrane had changed.With the help of SEM-EDX,FTIR,TEM and XPS characterizations,it could get conclusions that the surface of ceramic membrane loaded with CoFe₂O₄ catalyst after modified and the catalyst was uniformly distributed on the surface of ceramic membrane in a nano thin layer way.3 Performance reseach of removing methyl blue and ibuprofen.For 25mg/L methyl blue pollutant,the composite ceramic membrane coupling technology showed the best performance?>90%?.The results of parameters were as follows: a,the composite ceramic membrane calcined at 300 oC showed the best removal rate;b,a exponential increment relationship existed between the residual of methyl blue of composite ceramic membrane permeate and water head,the higher the water head the more serious membrane fouling happened.Increasing the dosage of PMS and initial pH in a certain range would promote composite ceramic membrane remove methyl blue.However,when the initial pH was below the isoelectric point,serious membrane fouling happened.Besides,the cobalt leaching amount at all used initial pH were blew 450?g/L.The composite ceramic membrane had a good stability even after four cycles experiment,its removal rate of methyl blue and normalized flux values maintained at 91.2% and 0.89.For ibuprofen?IBU?pollutant,when its concentration was 10?mol/L,the composite ceramic membrane coupling technology had a high removal rate to it?>99.5%?and showed a good ability of antifouling.3 Mechanisms research of removing methyl blue.The compare experiments results showed that the mechanisms removing methyl blue for the composite ceramic membrane coupling technology including adsorption,separation and catalytic degradation.With the help of streaming voltage test it could be obtained that the adsorption ability of composite ceramic membrane was far better than substrate ceramic membrane.It could be obtained from the radicals scavengers experiments that the dominant radical which take the role of oxidating degradation pollutant was SO4-..From the results obtained above,it can be concluded that the composite ceramic membrane coupling technology has a promosing application potential in low concentration organic waste water deep purification.