用酶溶液清洗被酱油污染的超滤膜研究

AN ENZYMATIC APPROACH TO CLEAN ULTRAFILTRATION MEMBRANE FOULED BY SOY SAUCE

膜污染降低了超滤法澄清酱油的经济性和实用性。本文通过红外光谱定性分析得出酱油对聚砜超滤膜的主要污染物为蛋白质和固形物。分别用胰蛋白酶溶液、氢氧化钠溶液清洗被酱油污染的聚砜超滤膜，并结合二者作用得出最佳的两步清洗流程，清洗效率可达９５％以上。通过ＳＥＭ 分析得出污染主要发生在膜表面形成凝胶层，并分析了胰蛋白酶－ 氢氧化钠溶液清洗流程的作用机理。高效的清洗流程和温和的清洗条件可增强超滤膜性能并延长膜的使用寿命。

Membrane fouling severely curtails the economical and practical implementation of ultrafiltration for the purification of soy sauce. The foulants deposited on the polysulfone membrane during the ultrafiltration of soy sauce were studied with IR spectroscopy and SEM. The main components of the foulants were protein, ash and some other solids. For foulants containing proteinaceous components, enzymatic cleaners play a vital role due to its hydrolysing effect on proteins. This paper investigates the cleaning effect of trypsin solution and sodium hydroxide solution on polysulphone membrane fouled by soy sauce. A more effective two-step cleaning protocol is achieved by combining the two cleaners. The cleaning efficiency is more than 95%. SEM results show that fouling appears to be mostly a surface phenomenon, for there are not much SEM observable foulants within the pores. The cleaning mechanism of the two-step cleaning protocol is also analyzed. Mild cleaning conditions are likely to be more economic both in terms of immediate cleaning costs and also in terms of extended membrane lifetime.