Dept. of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada N2L 3G1.
Biotechnol Prog. 2010 May-Jun;26(3):772-80. doi: 10.1002/btpr.378.
One of the primary problems in membrane-based protein separation is membrane fouling. In this study we explored the feasibility of employing Rayleigh light scattering data from fluorescence studies combined with chemometric techniques to determine whether a correlation could be established with membrane fouling phenomena. Membrane flux was measured in a dead-end UF filtration system and the effect of protein solution properties on the flux decline was systematically investigated. A variety of proteins were used as a test case in this study. In parallel, the colloidal behavior of the protein solutions was assessed by employing multiwavelength Rayleigh scattering measurements. To assess the usefulness of Rayleigh scattering measurements for probing the colloidal behavior of proteins, a protein solution of beta-lactoglobulin was used as a base-case scenario. The colloidal behavior of different beta-lactoglobulin solutions was inferred based on published data for this protein, under identical solution conditions, where techniques other than Rayleigh scattering had been used. Using this approach, good agreement was observed between scattering data and the colloidal behavior of this protein. To test the hypothesis that a high degree of aggregation will lead to increased membrane fouling, filtration data was used to find whether the Rayleigh scattering intensity correlated with permeate flux changes. It was found that for protein solutions which were stable and did not aggregate, fouling was reduced and these solutions exhibited reduced Rayleigh scattering. When the aggregation behavior of the solution was favored, significant flux declines occurred and were highly correlated with increased Rayleigh scattering.
膜分离过程中存在的主要问题之一是膜污染。本研究旨在探索利用荧光研究中的瑞利光散射数据结合化学计量技术来确定与膜污染现象是否存在相关性的可行性。在死端超滤过滤系统中测量了膜通量，并系统地研究了蛋白质溶液性质对通量下降的影响。在这项研究中，使用了多种蛋白质作为测试案例。同时，采用多波长瑞利散射测量评估了蛋白质溶液的胶体行为。为了评估瑞利散射测量对探测蛋白质胶体行为的有用性，使用β-乳球蛋白溶液作为基准情况。在相同的溶液条件下，根据该蛋白质的已发表数据推断出不同β-乳球蛋白溶液的胶体行为，其中除瑞利散射外还使用了其他技术。通过这种方法，观察到散射数据与该蛋白质的胶体行为之间存在良好的一致性。为了测试高聚合度会导致膜污染增加的假设，利用过滤数据确定瑞利散射强度是否与渗透通量变化相关。结果表明，对于稳定且不聚合的蛋白质溶液，污染减少，这些溶液的瑞利散射也减少。当溶液的聚集行为占主导地位时，通量显著下降，并与瑞利散射的增加高度相关。
