Evaluation On Adsorption And Desorption Behavior Of Protein On PVDF Membrane Surface

To clarify the influence of bovine serum albumin(BSA) on ultrafiltration membrane of polyvinylidene fluoride(PVDF) under different ionic conditions, the paper by vacuum adsorption mechanism and spin-coating machine connected to the development of a uniform surface coating PVDF ultrafiltration membrane gold chip,Quartz crystal microbalance(QCM-D) combined with homemade polyvinylidene fluoride(PVDF) chip investigated the adsorption and desorption behaviors of bovine serum albumin(BSA) on PVDF membrane surface, structure characteristics of adsorption layer, in order to explore the mechanism of ultrafiltration membrane protein foulant under different ionic conditions; and prepared a typical membrane contaminants carboxyl functional groups colloidal probe binds laboratory probe prepared by means of physical adhesion method, combined with atomic force microscopy(AFM) use carboxyl functional probes to measure the force under the corresponding ionic conditions, and membrane fouling and membrane performance recovery were studied and cleaning mechanism of different types of organic cleaning agent is investigated. The main conclusions are as follows:(1) For the effect of different ionic strength Na Cl on BSA foulant on ultrafiltration membranes, BSA adsorption amount and membrane flux decay rate increase with increasing ionic strength; however, when the ionic strength increase to l、10 and 100 m M, the sharp increase in hydration repulsion overshadowed change electrostatic repulsion, leading to surface adsorption of BSA and PVDF membrane fouling rate increases with ionic strength is significantly slowed. There are significant differences under different ionic strength PVDF surface structure of BSA adsorption layer. Underthe condition of low ionic strength, a rigid BSA foulant layer is formed on the membrane surface, and loose soft foulant layer is formed at high ion conditions.(2) BSA adsorption layer structure varies on the different salt ionic strengths. At high ionic strength, a large amount of Na+ tightly bound water molecules into the BSA molecules inside, deterioration absorption layer structure, and BSA foulant layer becomes soft. Membrane flux recovery rate is very small under conditions of low ionic,but flux recovery rate increases at high ionic strength conditions. The findings provides some basis for controlling membrane fouling.(3) As to different types of cleaning agents for cleaning the fouled membrane BSA,Na Cl cleaning effect compared to Na OH, HCl is better; While organic detergent SDS and Na Cl cleaning efficient is same, but SDS maybe make TOC increased. In addition,the water contains a large number of Na Cl, and a large amount of brine produced in the process of seawater desalination, which can be used for cleaning directly, Thus, Na Cl is more feasible.