聚乙烯醇(PVA)对模拟胞外聚合物(EPS)在错流超滤中膜污染的影响

Effect of Membrane Fouling by PVA Addition in Simulated EPS Solution on Cross-flow Filtration

研究了在模拟胞外聚合物(EPS)溶液中添加聚乙烯醇(PVA)对错流超滤膜过滤过程的影响.对有无添加PVA的模拟EPS溶液分别用错流平板膜进行超滤实验,用Hermia修正模型对实验数据进行拟合,分析验证膜污染机理.结果表明,无论是否添加PVA,模拟溶液的通量时间实验数据对滤饼堵塞模型的拟合度都最高,为0.8910.994;添加PVA的模拟EPS溶液形成的吸附阻力和膜污染阻力均比无添加的溶液高约0.5倍,滤饼比阻比无添加的溶液高约4倍,分别为2.291014和9.571014m1;模拟EPS溶液添加PVA后,通量对操作压力的敏感度增加,对膜面流速的敏感度却降低.

The effect of polyvinyl alcohol （PVA） addition on the performance of cross-flow membrane filtration of model extracellular polymeric substances （EPS） solution was studied. Filtrations of model EPS solution with and without PVA were conducted in a cross-flow filtration cell through ultrafiltration （UF） membranes respectively. Hermia modified model was used to check the fouling mechanism by fitting of the experimental data, The results show that the cake filtration model fits to the experimental data the best in UF experiments regardless of addition of PVA, the degree of fitting ranges from 0.891 to 0.99i, the adsorption resistance and membrane pollution resistance of the model EPS solution with addition of PVA is higher by half than that of model EPS solution, the specific cake resistance is four times higher, 2.29×10^14 and 9.57×10^14 m-1 respectively, the sensitivity of flux to the operating pressure is increased with addition of PVA, but the sensitivity to the velocity of the membrane surface reduced.