采用芳香聚酰胺纳滤膜和反渗透膜处理模拟大豆乳清废水,研究溶液浓度、操作压力、膜面流速、pH等对渗透通量与截留效果的影响,并探讨蛋白污染膜的清洗条件。研究结果表明:在一定操作压力下,渗透通量随着料液浓度的增加而减小,随膜面流速的增加而增加;对一定浓度的原料液,在操作压力小于0.7 MPa时,渗透通量随压力的增大而增大,当操作压力大于0.7 MPa时,渗透通量不再随压力的增大而增大;大豆乳清废水的等电点pH为4.5,当pH大于等电点时,渗透通量和截留率随pH的增大而增大;芳香聚酰胺反渗透膜对纳滤透过液的NaCl截留率在90%以上;蛋白污染纳滤膜经pH=10的NaOH溶液清洗后,通量可完全恢复。
The aroma polyamide(APA) nanofiltration(NF) membrane and reverse osmosis(RO) membrane were used for the treatment of simulative industrial soybean whey wastewater.The effects of concentration,trans-membrane pressure(TMP),velocity,and pH on the permeate flux and retention were investigated,and the cleaning of the whey protein fouled membrane was also studied.The results show that the flux decreases with the increase of the concentration,and increases with the increase of the velocity at a certain TMP.The permeate flux increases with the increase of TMP when TMP is within 0.7 MPa,and the permeate flux changes little when TMP is greater than 0.7 MPa.The pH of isoelectric point(IEP) is 4.5,when the pH of the soybean whey wastewater is greater than IEP,both the flux and retention increase with the increase of pH.The removal of NaCl in the filtrate of nanofiltration is over 90% by the treatment of reverse osmosis.Water flux of the cleaned NF membrane can recover by the cleaning with NaOH solution at pH 10.