Preparation Of Honeycomb PVDF/Ceramic Composite Membrane And Its Separation Performance Research

With the rapid development of modern society and the rapid increase of the population density,human demand for fresh water resources increased sharply.In return water pollution has become more and more serious,and oily wastewater is one of the most important water pollutions.Membrane separation technology with the high water purification efficiency,low energy consumption,large processing capacity and easy operation was used as the optimization technology to solve the problem of the current water pollution.This topic prepares to make organic-inorganic composite membrane with organic materials and inorganic materials.The composite membrane not only has good chemical stability and high thermal stability,but also holds strong hydrophilicity.The hydrophilicity and pore size of the composite membrane can be controlled by controlling the proportion of hydrophilic components in organic casting membrane.It can help to reduce the effects of membrane fouling and prolong the life time of membrane.In this paper,PVDF?CA and pore former of Li Cl are used to make casting solution.Honeycomb ceramic treated with SiO₂ sol and silane coupling agent is used as the carrier.The influence of mass fraction of PVDF/CA and Li Cl,the heating treatment temperature on the properties of composite membrane were studied.The result shows that the best optimal performance of ceramic composite membrane is prepared by 7% PVDF,1% CA,1% Li Cl and the heating treatment temperature of 70 ?.The water permeate flux and oil removal rate of honeycomb PVDF/ceramic composite membrane reach 54.2 L/?m²·h?and 98.7% under the pressure of 0.1 MPa.The composite membrane is characterized by thermogravimetry analysis?TG?,the infrared absorption spectra?FTIR?,scanning electron microscope?SEM?,surface contact angle tester.The result shows that the hydroxyl groups are successfully introduced on the composite membrane surface and the thermal stability of the composite membrane is improved too.The decomposition rate of membrane began to increase at about 450 ? and the membrane was completely decomposed at about 500 ?.It was inferred that the proportion of organic components in the composite membrane was about 9.02%.By changing the mass fraction of Li Cl and CA,the SEM showed that the porosity and pore size of the composite membrane became larger with the increase of Li Cl and the contact angle of the composite membrane became smaller with the increase of CA.The hydrophilicity of the composite membrane was improved.In the process of low concentration of oily wastewater treatment,the influence of the oil concentration of the feed liquid,operating pressure and the processing time on the performance of honeycomb PVDF/ceramic composite membrane prepared by the optimum conditions were studied.When filtered 200 mg/L of oily wastewater,the composite membrane flux maintained at 25.1 L/?m²·h?after 180 min under the pressure of 0.2 MPa.