用膜结构参数模型评价溶解性有机物分子量分布对超滤膜污染的影响研究

研究了不同预处理对原水分子量分布的改变和对膜透水通量的影响,用膜污染的结构参数模型,评价了分子量分布对平均孔径和膜孔密度的影响。结果表明:(1)经过不同的预处理后,原水的分子量分布有所改变,混凝对大分子量有机物去除率较高,PAC吸附对小分子量有机物去除率较高,臭氧PAC联用预处理使大分子量有机物和小分子量有机物均有所去除。(2)分子量分布对膜通量影响较大。(3)通过试验并应用膜结构参数模型,评价了分子量分布对膜平均孔径和膜孔密度的影响,表明小分子量有机物易引起孔内吸附,大分子量有机物容易在膜面附着。

RESEARCH ON THE INFLUENCE OF DISSOLVED ORGANICS MOLECULAR WEIGHT DISTRIBUTION ON MEMBRANE FOULING WITH THE MODEL OF MEMBRANE STRUCTURE PARAMETERS

The influence of different pretreatments on the changes of raw water molecular weight distribution and membrane permeability was studied, then the influence of molecular weight distribution on the mean pore size and pore density of membrane was evaluated with the model of membrane fouling structure parameters.The results showed:(1)after different pretreatments, the molecular weight distribution of raw water changed,coagulation could effectively remove high molecular weight organics,PAC adsorption was effective in removing low molecular weight organics, O_3-PAC pretreatment could remove both high molecular weight and low molecular weight organics.(2)The molecular weight distribution had great influence on membrane permeation.(3)The influence of molecular weight distribution on the membrane mean pore size and pore density was evaluated by the test and the model of membrane parameters,which showed:low molecular weight organics could easily cause interior adsorption, and high molecular weight organics could easily cause membrane surface blocking.