本研究以掃流式無機薄膜過濾系統探討在不同操
作方法及操作參數下之蛋白質溶液過濾行為與結垢現
象,實驗溶液為BSA,操作參數有透膜壓差、濃度、pH值、液體速度、氣體速度及逆洗頻率等。實驗結果顯示,
pH 值為3時濾速最高、pH 值為7 時次之、pH 值為4.9
時濾速最低,由於濃度極化層的阻力與BSA 之電性及
形狀有關,pH值為3時BSA 為帶狀且表面帶電,濃度
極化層不易堆積,因此濾速最高,pH 值為4 . 9 時, BSA
為球狀且表面不帶電,因此所形成之濃度極化層最緻
密,使得濾速最低。而由不同操作方式之淨濾速分析可
知,通氣為最佳的操作方式,逆洗會因清洗耗去的港、液
量而使濾速低於一般過濾。通氣可移除濃度極化層,防
止BSA 粒子吸附於且其面,且不需耗費濾液清洗,因此
具有最高的淨濾速, pH 值為3 時,通氣約可提高60
%之濾速。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 to
search the manner for increasing the flux. BSA was
selected as the testing solution and the operating
parameters such as transmembrane pressure, solution
concentration, pH value, liquid velocity, air velocity and
back washing frequency. For varying the pH, the
experimental results show that the permeate flux is
maximum at pH=3 and is minimum at pH =4.9. The BSA
particle's shape and surface charge were determined by the
pH value. At pH=3, the BSA molecules are linear with
surface charge, the BSA polarization layer in the filtration
has a loose structure results in a lower filtration resistance.
At pH = 4.9, a compact BSA polarization layer's structure
was formed due to the neutral and nearly spherical BSA
molecues. Basing on the analysis of net permeate flux, the
gas sparging method is better than the backwashing for
flux enhancement. The gas sparging can effectively
remove the polarization layer and reduce the BSA
deposition on the membrane. Furthermore, no permeate is
wasted for washing in gas sparging. At pH =3, the flux
increment by gas sparging is up to 60%.
關聯:
2008年輸送現象及其應用研討會論文摘要集 ( 2008 Symposium of transport phenomena and applications abstract book)