超滤膜污染的光学在线监测和阻力分布研究

采用光散射颗粒分析仪(PDA)对截留液中颗粒物的浓度变化进行在线监测,并利用过滤体系中颗粒的质量守恒分析原理,建立了超滤膜污染的光学在线监测分析系统,并分别对截留分子量为1万,5万,10万三种聚醚砜超滤膜过滤高岭土悬浊液特性进行了分析研究。结果分析表明截留分子量越小的PES膜渗透单位体积液体时颗粒沉积量越多,也就是说具有相同沉积量的膜,截留分子量越小其具有的水力阻力越大。论文提出的光学在线监测方法为研究悬浮物质的膜污染提供了一种新的研究思路。

Application of Optical Online Monitoring Method for Membrane Fouling and Resistance Build-up on Ultrafiltration Membranes

Characteristics of particle deposit on the polyethersulfone(PES)membranes of three MWCO levels as 10k,50k and 100k Da for the filtration of kaolinite clay suspensions were investigated. A particle dispersion analyzer (PDA)was introduced to the study for monitoring the variation of particle concentration in the concentrate. Using the PDA online monitoring data and conducting mass balance analysis of particles in the UF filtration system,the deposit weight on the membrane surface was calculated. Analysis was further done on the relationship between the unit surface deposit weight and resistance build-up on the membranes of different MWCOs according to Darcy’s law and using flux data. As a result,a PES membrane of smaller MWCO was found to accumulate larger quantity of deposit per unit permeate volume than that of larger MWCOs. With the same weight of membrane deposit,higher hydraulic resistance was built up on smaller MWCO membrane than larger ones. PDA online monitoring technique provided a new approach for the study of membrane fouling by suspended particles.