梯度纳米纤维膜在纯生啤酒中的除菌过滤研究

Research on sterilization and filtration of gradient nanofiber membranes in pure draft beer

针对目前商业化纯生啤酒用除菌滤膜存在孔径分布宽、抗污性差、膜孔易堵塞、可重复使用性差等问题,利用熔融挤出相分离法制备了不同直径大小的乙烯-乙烯醇共聚物(EVOH),通过将粗、细纳米纤维在上、下层的先后排列构筑了一种梯度结构纳米纤维膜。通过对梯度纳米纤维膜过滤性能、抗污性及可重复使用性等进行研究,发现梯度纳米纤维膜对10 g/L的酵母浸膏发酵液重复过滤后,稳定后的通量为22660 L m^(-2)h^(-1),远高于Pall®商业膜(4840 L m^(-2)h^(-1))。经高温蒸汽灭菌处理后的梯度纳米纤维膜的稳定通量为6600 L m^(-2)h^(-1),而商业膜仅为1760 L m^(-2)h^(-1),表现出优异的耐高温水蒸气性能。此外,污染后的梯度纳米纤维膜经80℃水清洗后的通量恢复率可达43%,而商业膜的通量恢复率仅为32%,表明梯度纳米纤维膜显示了优异的可重复使用性。为纯生啤酒用除菌滤膜的国产化替代提供了一种新的途径。

To address the problems of wide pore size distribution,poor fouling resistance,easy clogging,and poor reusability of sterilization commercially available filters for the filtration of pure draft beer,poly(vinyl alcohol-co ethylene)(EVOH)nanofibers with two different diameter sizes were prepared by using the melt extrusion phase separation method,and a gradient structure nanofiber membrane was constructed by sequentially arranging coarse and fine nanofibers in the upper and bottom layers,respectively.The filtration performance,fouling resistance,and reusability of the gradient nanofiber membrane are investigated.It is found that the gradient nanofiber membrane has a stabilized flux of 22,660 L m^(-2)h^(-1)after repeated filtration of 10 g/L yeast extract fermentation broth,which is much higher than that of the Pall®commercial membrane(4840 Lm^(-2)h^(-1)).The stabilized flux of gradient nanofiber membrane after autoclaving treatment is 6600 Lm^(-2)h^(-1),compared to the commercial membrane which is 1760 Lm^(-2)h^(-1),showing excellent high-temperature water vapor resistance.In addition,the flux recovery rate of the contami-nated gradient nanofiber membrane after 80℃water rinsing is up to 43%,while the flux recovery rate of the com-mercial membrane is only 32%.The results show that the gradient nanofiber membranes have excellent reusabili-ty.This provides a new way for the localized replacement of sterilization filters for pure draft beer.