双轴旋转超滤膜组件过滤厌氧泥水混合液

Filtration of anaerobic sludge mixed liquor using double-shaft rotary ultrafiltration membrane module

设计开发了一套中试规模的双轴旋转超滤膜组件系统.系统容器容积120 L,内装填的有效膜面积为4 m2.试验选用两种不同截留分子量(5万和10万)的PVDF超滤膜,采用该系统处理厌氧生物反应器内泥水混合液,研究了膜截留分子量、膜渗透通量、过膜压差、膜旋转速度之间的相互关系.结果表明,一定膜旋转速度下,随着过膜压差的提高,存在一个膜极限渗透通量;随着膜旋转速度的降低,膜极限渗透通量明显下降,且膜极限渗透通量出现时对应的过膜压差往低压方向迁移;截留分子量大小对膜过滤行为的影响在高压、高转速区有减弱趋势.

A set of pilot scale double - shaft rotary ultrafiltration membrane module was designed and developed. This module has a capacity of 120 L with an membrane area up to 4 m^2 of flat membrane. Two kinds of PVDF membranes with the cut - off molecule weight of 50 k and 100 k respectively were used in this module to filtrate anaerobic sludge mixed liquor. Relationships among the membrane cut- off molecule weight permeate flux, transmembrane pressure, and membrane rotary speed were investigated. Results showed that there was a critical flux when the transmembrane pressure increased at a constant membrane rotary speed. With the decrease in membrane rotary speed, critical fluxes were observably decreased, and the lowest transmembrane pressures corresponding to the appearance of critical flux moved to lower pressure point. Effect of cut - off molecule weight on the membrane filtration became weak especially at the high pressure and high rotary speed zone.