高含盐模拟废水的纳滤膜和反渗透膜脱盐特性

Desalination Characteristics of NF Membrane and RO Membrane in High Salinity Simulated Wastewater

通过可低压操作的NF膜和RO膜的高含盐模拟废水分离试验,本文探讨在不同进水pH条件下的脱盐效果,分析盐浓度对膜通量和脱盐率的影响。结果表明,在pH≥5条件下,RO膜对单价和二价无机盐的脱盐率均可至少达到85%,NF膜对二价盐的脱盐率可至少达到70%,但单价盐的脱盐率呈低值;在膜分离过程中,两种膜的膜通量和脱盐率随进水的盐浓度上升呈下降趋势。RO膜的膜通量对盐浓度变化的敏感度高于NF膜,但脱盐率的盐浓度变化敏感度则相反。

In this paper,the desalination effects were investigated under different pH conditions in influent,and the effects of membrane flux and desalination rate were analyzed under different salt contents through the separation experiments of high salinity simulated wastewater with NF membrane and RO membrane that could be operated under low pressure.The results showed that the desalination rates of RO membrane for monovalent and divalent inorganic salts could reach above 85%at pH≥5,and that of NF membrane for divalent salts could reach above 70%,but for monovalent salts,the desalination rate was the lowest;the membrane flux and desalination rate of the two membranes decreased with the increase of salt concentration in the process of membrane separation.The sensitivity of membrane flux in RO membrane was higher than that in NF membrane react to the changes in salt concentration,while the sensitivity of desalination rate in RO membrane was lower than that in NF membrane.