水过滤中典型污染物对聚醚砜膜的污染性研究

用液致相分离法制备聚醚砜膜(PES), 泡点—流速法测定孔径分布, 研究腐殖酸、聚氯化铝和多种聚丙烯酰胺等典型污染物溶液对膜的过滤性能, 并依次用水、酸、碱对污染膜进行清洗, 测定膜阻力构成和变化, 进而研究各种物质对膜的污染程度和清洗效果. 研究结果表明: 相同质量浓度下, 腐植酸污堵程度最重, 聚丙烯酰胺次之, 聚氯化铝最轻. 对聚丙烯酰胺而言, 其对PES膜的污堵程度按阳离子型、阴离子型和非离子型顺序依次略有减弱. 同类絮凝剂之间, 高分子量物质的污堵程度与低分子量相差不大. 膜反复利用时, 采用碱对膜进行清洗的效果最好, 水洗和酸洗较差.

Fouling Effect of Typical Pollutants on Water Filtration with Polyethersulfone Membrane

Polyethersulfone (PES) membrane is prepared using the liquid induced phase separation method. The membrane pore size distribution is measured using the Bubble point-mean flow method. The humic acid, poly aluminum chloride and different ionic polyacrylamide solution are filtrated with PES membrane to characterize the membrane fouling property. The polluted membranes are washed by water, acid and alkali. The membrane resistance constitution is measured. The different materials effect on membrane fouling degree and cleaning effect are investigated further. The results show that, under the same concentration level, the fouling degree of humic acid is found to be worse than that of polyacrylamide, and poly aluminum chloride is identified to be the best. For the polyacrylamide, the fouling degree decreases along with the priority of cationic, anionic and nonionic polymer. Among the flocculants of the same kind, the fouling degree of high molecular weight material is similar to that of low molecular weight. When the membrane is used repeatedly, the cleaning effect of alkali is the best, while acid and water are not as well by comparison.