無機管式薄膜過濾蛋白質溶液之探討

Investigation on the Filtration of Protein Solution by Inorganic Tubular Membrane

林凱尉(Kai-Wei Lin)

指導教授 ： 鄭東文

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2007年)

https://doi.org/10.6846/TKU.2007.00850

摘要

本研究以掃流式無機薄膜過濾系統探討在不同溶液性質及操作參數下之蛋白質溶液過濾行為與結垢現象，以尋求提升濾速之操作方式。實驗溶液為BSA與β-cyclodextrin之混合溶液，操作參數有透膜壓差、濃度、pH值、液體速度及氣體速度等，定量薄膜結垢之阻力，並建立濾速分析模式。
實驗結果顯示，BSA溶液之濾速在等電點時較其它pH值為低，這是因此時BSA極化層結垢較為緊密所致；含有β-cyclodextrin之雙溶質系統，其濾速較純BSA溶液來得低，此因β-cyclodextrin可進入薄膜孔道形成內部結垢所致。雙溶質系統中薄膜對β-cyclodextrin之阻隔率隨溶液pH值不同而有所改變，在BSA等電點時β-cyclodextrin之阻隔率大於遠離BSA等電點之阻隔率。在低液體流速下，通入氣體可有效提升濾速，因氣泡可以增進對膜面之擾動。
阻力計算結果顯示，β-cyclodextrin所產生之內部阻力大於BSA所形成之外部阻力。在雙溶質溶液中，由於BSA於膜面產生的結垢層阻擋了β-cyclodextrin透膜，使孔洞阻塞阻力值下降。以滲透壓模式計算理論濾速發現，理論濾速與實驗濾速趨勢相同。而在低液體速度時，實驗的濾速會比理論濾速高，可能是理論計算中低估膜面擾動所致。

關鍵字

薄膜結垢 ； 等電點 ； 阻隔率 ； 通氣

並列摘要

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.

並列關鍵字

Membrane fouling ； Isoelectric point ； Rejection ； Gas-sparging

參考文獻

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