Investigation on the Filtration of Protein Solution by Inorganic Tubular Membrane

• Main Authors: Kai-Wei Lin, 林凱尉
• Other Authors: 鄭東文
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/69849582899395898994

碩士 === 淡江大學 === 化學工程與材料工程學系碩士班 === 95 === In this study, the inorganic membranes were employed in a cross-flow filitration system to discuss the flux and fouling behavior of protein solutions under various solution properties and operating parameters, and to search the manner for increasing the flux. Mixture of BSA and β-cyclodextrin was selected as the testing solution and the operating parameters such as transmembrane pressure, solution concentration, pH value, liquid velocity and air velocity were considered to determine the membrane resistance and establish the model for flux analysis. Experimental result indicates that the flux of BSA solution at its isoelectric point is lower than that at other pH values; this is due to a denser polarization layer formed at its isoelectric point. Because of the internal fouling ofβ-cyclodextrin, the flux of solution containing β-cyclodextrin is lower than that of pure BSA solution. In binary solutions, the β-cyclodextrin rejection by membrane varies with the change of pH value; the rejection of β-cyclodextrin at the isoelectric point of BSA is higher than that at the condition far away from the BSA isoelectric point. Under low liquid velocity, flux can be enchanced efficiently by gas-sparging due to gas slugs increase the turbulence at the membrane surface. According to the resistance-in-series model, internal fouling by β-cyclodextrin is higher than the external fouling by BSA. When in binary solution, fouling layer formed by BSA on membrane surface could reject β-cyclodextrin transmembrane, and reduce internal fouling resistance. Estimation by the osmotic pressure model, the trend of theoretical flux agrees well with experiment flux. At low liquid velocity, the experiment flux is higher than theoretical flux, perhaps due to the underestimation of turbutance on the membrane surface.