Preparation Of Polymer-based Fiber Materials And Research On Their Performance In Treating Oily/dye-containing Wastewater

In order to fulfill the aim of treating oil pollution,poly(butyl acrylate-co-hydroxyethyl methacrylate)and poly(butyl methacrylate-co-hydroxyethyl methacrylate)were synthesized by solution polymerization in this study.Solution blending and electrospinning were used to prepare microstructurally adjustable fibrous membrane material which could be used to separate different oil/water mixtures,and its separation capacity for different oil/water mixtures was explored.The results demonstrated that the fibrous membrane obtained by blending the two copolymer solutions in the volume ratio of 3:7 showed significant separation capability for diesel/water mixture and sunflower oil/water mixture.When it was repeatedly used,the separation time for the two oil/water mixtures were lower than1?30?and 6?30?,respectively.Tetrahydrofuran(THF)was introduced into the above-mentioned blending solution to continually adjust the microstructure of electrospun fibrous membrane,and the obtained fibrous membrane could separate high viscosity emulsified oil from water quickly.In order to accomplish the objective of remedying the water polluted by dyes,homogeneous blend of different molecular weight polyacrylonitrile(PAN)was adopted in this work to solve the shrinkage problem of hollow fiber membrane fabricated from high molecular weight PAN,to enhance the application performance of low molecular weight PAN hollow fiber membrane,and to adjust the porosity,pore size distribution and hydrophilicity of hollow fiber membrane.Structurally optimized membrane was then chosen as a substrate to support in-situ generated Fe/Mn oxides,and the final hollow fiber membrane was used to remove dyes from their solutions in the presence of H₂O₂.The results showed that the flux of methylene blue(MB)aqueous solution was 83.7 L/m²·h,which was much higher than 29.1 L/m²·h of high molecular weight PAN hollow fiber membrane.MB removal efficiency was 97.3%,which was higher than 62.3%of low molecular weight PAN hollow fiber membrane.PAN homogeneous blend hollow fiber membrane also had application advantages of decreasing H₂O₂dosage,reducing operation pressure,and raising MB removal efficiency when compared with other membranes reported by literature,and it could be reused 25 times to remove MB or other dyes from their solutions almost without any obvious removal efficiency loss.In order to further optimize the porous structure of above-mentioned membrane,a certain amount of graphene oxide(GO)was doped into hollow fiber membrane,doping GO could greatly enhance the porosity of hollow fiber membrane;it could narrow pore size distribution;it could increase average pore size;and it could raise the flux.When a small amount of GO was doped into PAN hollow fiber membrane,it could direct the growth of iron/manganese oxide and make villi-like iron/manganese oxide grow onto the inner surface of PAN hollow fiber membrane.When compared with the hollow fiber membrane without GO,the hollow fiber membrane prepared in the presence of 0.15%GO could support more iron/manganese oxide during modification,and it also had better hydrophilicity.0.15%GO-doped PAN hollow fiber membrane showed a porosity of 33.8%,which was much higher than 24.7%of PAN homogeneous blend hollow fiber membrane.As the water containing H₂O₂and MB was then pumped into the lumen side of modified hollow fiber membrane,with the help of pressure,the water passed through the shell side of modified hollow fiber membrane,and MB was at the same time was removed from the water.After 30cycles,MB removal efficiency was found to still be higher than 94%.