聚乙二醇超滤过程的考察及模型化分析

Process of polyethylene glycol ultrafiltration and modeling analysis

采用截留相对分子质量为2 500的GH超滤膜,对不同相对分子质量的聚乙二醇(PEG)溶液进行过滤分离,考察了PEG相对分子质量、浓度、超滤压力等因素对超滤过程的影响。结果表明:相同条件下超滤膜对PEG去除率随着相对分子质量和浓度的增大而增大,对PEG 4 000的截留率可以达到96.7%,但截留并不是随着压力的增大而单调增大,当PEG相对分子质量≥2 000时出现压力增大截留减小现象。同时,运用细孔模型模拟表征了GH膜的等效孔径和等效膜厚,解释了PEG超滤过程中的分离现象,分析了超滤机制的内在因素。

The polyethylene glycol（PEG） removal experiments with different molecular weights were carried out by molecular weight cut off（MWCO） 2 500 GH Ultrafiltration（UF） membrane to investigate the effects on removal of different molecular weights PEG,such as operating pressure and concentration.Results showed that the rejection of PEG increased as molecular weight and concentration increased under the same conditions with the rejection of PEG4 000 of 96.7%,but the rejection did not monotonically increased with pressure increasing.When PEG molecular weight was over 2 000,the rejection decreased with the pressure in creased.Pore model was modeled to characterize the effective pore diameter and thickness of the membrane.The separation of PEG ultrafiltration was explained and the internal factors of UF mechanism were analyzed.