Study On ?-cyclodextrin Modified Polyamide Reverse Osmosis Membrane

In this paper,the reverse osmosis composite membrane was prepared by interfacial polymerization method.The preparation process of polyamide functional layer was explored and optimized.The reaction time,post-treatment temperature of interfacial polymerization,addition of surfactant and modifier(?-CD)were investigated.The effect of the method on the properties of the composite membrane and the structure of the active separation layer,as the reaction time increases,the water flux of the composite membrane decreases and then tends to be stable,and the retention rate increases and then gradually stabilizes.The flux of the membrane is less affected by the post-treatment temperature and remains substantially stable.The retention rate of the membrane tends to be stable with the increase of the surfactant,and the water flux of the membrane decreases and then gradually stabilizes.The?-cyclodextrin was mixed with m-phenylenediamine(MPD)as the aqueous phase and trimesoyl chloride(TMC)was used as the organic phase.A novel?-cyclodextrin(?-CD)/polyamide was prepared by in-situ interfacial polymerization.This method can increase the pure water flux and the salt rejection of the composite membrane.When the concentration of?-CD in the aqueous solution was 1.5%(w/v),the retention rate of the modified composite membrane to NaCl remained at a high level,and the water flux of the membrane reached 1.52 times that of the unmodified membrane.By optimizing the membrane process conditions,the water flux of the reverse osmosis composite membrane was significantly improved.When the overall performance of the composite membrane was optimized,the membrane was used to treat NaCl solution.The water flux was 53.73 L/m~2h.The retention rate was 98.7%.The structure and properties of the composite membrane were investigated by testing the water flux,retention,contact angle,surface roughness,and elemental composition of the membrane.The?-CD/polyamide composite membrane was used to treat the biogas slurry.The water flux was significantly better than that of the polyamide membrane without?-CD,and the retention rate remained basically unchanged,and the membrane performance was stable during the long-term operation.