正渗透去除单宁酸的影响因素分析

以单宁酸溶液作为原料液、NaCl溶液作为汲取液,在不同的膜朝向、汲取液和原料液浓度、膜面流速、原料液温度、pH值条件下,研究正渗透膜对单宁酸的去除效果。结果表明,汲取液浓度越高、原料液浓度越低、原料液温度越高、错流流速越大、膜活性层朝向汲取液运行模式均有助于提高膜通量,盐通量与膜通量呈正相关;不同影响因素条件下,正渗透膜对单宁酸的截留率均在97%以上,而在膜活性层朝向原料液模式下运行,对单宁酸的截留率更高。

Influence Factors of Forward Osmosis on Tannic Acid Removal

The removal of tannic acid by forward osmosis membrane under different membrane orientation,concentration of draw solution and feed solution,membrane surface velocity,temperature of feed solution and pH was investigated by using tannic acid solution and NaCl solution as the feed solution and draw solution.The higher concentration of draw solution,lower concentration of feed solution,higher temperature of feed solution,higher cross flow velocity,and operation mode of the membrane active layer towards the draw solution were all beneficial to improve the membrane flux,and the salt flux was positively correlated with the membrane flux.The rejection rates of tannic acid by the forward osmosis membrane were all above 97% under different influencing factors,while the rejection rate was higher when the membrane active layer was running towards the feed solution.