聚醚砜膜提纯乳糖的研究

Investigation of purification of lactose by PES membrane

以聚醚砜（PES）为膜材料，聚乙烯吡咯烷酮（PVP）为添加剂，N，N-二甲基乙酰胺为溶剂，采用相转化法制备了对PEG的截留分子量为20000的聚醚砜超滤膜．通过对操作压力、料液的温度和浓度等条件的变化对蛋白质截留率、膜通量及乳糖透过率影响的分析，研究了不同的影响因素对乳糖超滤效果的影响规律．并确定了最佳工艺条件：压力在0．3MPa左右较适宜，温度为50～60℃，料液浓度为100～150g／L，处理时间为45～60min．比较了不同清洗剂对PES膜超滤性能恢复的效果．结果显示，当超滤1h通量减少一半时，用0．5％的NaOH清洗20min后就可以恢复70％的膜通量．

The flat ultrafiltration membrane for the cut - off molecule weight of 20 000 PEG, which was successfully prepared by phase inversion method, with polyethersulfone（PES） as raw materials, dimethylacetamide as solvent and polyvinypyrrolidone （PVP） as pore forming additive. The effects of operation pressure, the feed concentration and temperature on permeate flux, protein rejection and lactose permeability were investigated. And the optimum conditions are temperature 50-- 60 ℃, about 0.3 MPa and lasting for 45 -- 60 min. Feed con- tent is 100--150 g/L. Compare with the ultrafiltration membrane regeneration by different cleaning regents, the home - made membranes that were fouled with protein and other components of lactose feed could be regenerated very well. The results showed that the lactose permeability was decreased by 50 % after lh. Even 0.5 % NaOH solution was able to recovery the 70 % of permeate flux during 20 min.