中空纤维膜超滤聚丙烯酸钠溶液

研究聚丙烯酸钠（PAAS）溶液的超滤行为，考察各操作参数对膜通量（J）和截留系数（R）的影响，结果表明，J随运行时间延长衰减不明显，随压差增大呈线性递增，随温度升高而增大，pH高于5时J基本不变；R随压差增大或温度升高均下降，随pH增大而增大。建立膜阻力（rf）模型，研究影响rf的主要因素，发现，rf随压差增大而增大，随温度升高而减少，pH低于5时rf随pH增大而迅速下降。研究PAAS溶液浓缩过程，当体积浓缩因子为16时，J衰减明显，截留液PAAS浓度（Cr）呈线性递增，渗透液PAAS浓度（Cp）在较长时期内基本不变，至浓缩后期，Cp轻微下降。以去离子水对浓缩液予以洗涤，随着洗涤液体积增大，Cr轻微下降，Cp逐渐趋于零。

Uitrafiltration behaviors of poly （acrylic acid） sodium salt solutions by using hollow fiber membranes

Ultrafiltration behaviors of poly （acrylic acid） sodium （PAAS） solutions were studied. The effects of various parameters on permeate flux （J） and rejection coefficient （R） were investigated. Results show that J declines slightly with time. Increasing transmembrane pressure or temperature results in increasing J. A constant J is observed until pH is reduced below 5. R decreases with transmembrane pressure or temperature, but increases with pH. The resistance model for membrane fouling was established. The effects of various param- eters on membrane resistance （rf） were investigated. It is found that, rf increases with transmembrane pressure, but decreases with temperature. If pH is reduced below 5, rf decreases rapidly with pH. Then, the concentration experiment was carried out. J declines significantly when volume concentration factor reaches 16. PAAS concen- tration in the retentate （Cr） increases linearly, whereas PAAS concentration in the permeate （Cp） does not change during a long period until the concentration process is coming to the end. Furthermore, the concentrated PAAS solution was washed by using the deionized water. When the volume of the deionized water increases, Cr decreases insignificantly and Cp decreases gradually to zero.