Preparation And Hydrophilic Modification Of Polyethersulfone Hollow Fiber Ultrafiltration Membrane In Pilot Scale

Polyethersulfone（PES）has attracted wide attention in the field of membrane materials because of its good mechanical properties and chemical stability.However,because of its high hydrophobicity,it is easy to cause membrane fouling,reduced separation efficiency,and reduced operating life.Therefore,improving the hydrophilic properties of polyethersulfone is the key to improving its membrane separation performance.However,most of the current research on the hydrophilic modification of polyethersulfone remains in the laboratory stage,and there are few pilot tests on the hydrophilic modification of polyethersulfone.The pilot-scale hydrophilic modification of polyethersulfone membranes is carried out.Therefore,it is of great theoretical and practical significance to study the hydrophilic modification of polyethersulfone at the pilot scale.First of all,In this paper,the PES hollow fiber ultrafiltration membrane was prepared by the liquid-solid phase conversion method using a pilot-scale production line,and the influence of the basic components of the casting solution and the spinning process parameters on the structure and performance of the PES hollow fiber ultrafiltration membrane was deeply studied.Influence,determine the appropriate spinning process conditions.The test shows that the concentration of Tween 80 is 3 wt%,the concentration of PES is 16 wt%,the concentration of PEG400 is 6 wt%,the concentration of PVP is 6 wt%,the temperature of the casting liquid is80oC,and the temperature of the coagulation bath is 45oC.The air gap distance is 40 cm,and the winding speed is 18.5 m·min^-1.The prepared ultrafiltration membrane shows good performance.Secondly,this paper uses three inorganic nanomaterials（nano silica,calcium carbonate,graphene oxide）to blend and modify PES hollow fiber ultrafiltration membranes,and explore the effect of the addition of inorganic nanomaterials on the structure and performance of the modified membrane.Experiments show that the above-mentioned inorganic nanomaterials can increase the flux of PES membrane to a certain extent.When the addition amount of nano-Si O₂is 0.9 wt%,the water flux of nano-Si O₂/PES modified membrane is the largest,which is 431L·m^-2·h^-1;when the addition amount of nano-Ca CO₃ is 0.6 wt%,nano-Ca CO₃/PES modified The membrane has the largest water flux of 390 L·m^-2·h^-1;when the GO addition amount is 0.1wt%,the GO/PES modified membrane has the largest water flux of 480 L·m^-2·h^-1,and has good flux stability.Finally,a sample of PES hollow fiber membrane modified by graphene oxide was selected to treat dye wastewater with Congo red as a model pollutant,and the performance of the modified membrane material to remove pollutants was investigated.When the dye wastewater concentration is 20 mg·L^-1,the turbidity removal rate of the PES membrane is 88.4%,and the COD removal rate is 70.5%;the turbidity removal rate of the GO/PES modified membrane is91.6%and the COD removal rate is 80.9%.When the simulated dye wastewater is p H=7,the turbidity removal rate of the PES membrane was 86.2%,and the COD removal rate was 70.8%;the turbidity removal rate of the GO/PES modified membrane was 92.6%and the COD removal rate was 78.2%.The modified membrane exhibits higher membrane flux and better retention performance.