荷电纳滤膜从水溶液中脱除或透过的是离子还是盐类分子  

Ions or salt molecules rejected or permeated by the charged nanofiltration membrane from the solutions

作　　者：祝振鑫[1] ZHU Zhenxin(Beijing Research Institute of Chemical Engineering and Metallurgy, Beijing 101149, China)

机构地区：[1]核工业北京化工冶金研究院,北京101149

出　　处：《膜科学与技术》2020年第3期1-6,共6页Membrane Science and Technology

摘　　要：根据E.Glueckauf 1965年提出的多孔膜脱盐的传质模型,讨论了荷电纳滤膜的分离机理:在膜上电荷的吸引和水力压力驱动下,一个异性电荷的离子是与它的反离子一起以结合成电中性的离子对的形式即盐分子的形式进入膜孔和渗透过膜,或被膜截留的,并在产水侧再次离解为水合阳离子和水合阴离子.也讨论了正负离子所带的电荷对荷电纳滤膜分离性能的影响,提出了离子表观截留率的概念,并解释了在某些情况下离子的表观截留率会出现负值的现象,最后为“纳滤膜”和“纳滤”这两个术语推荐了一个新的简短定义。According to Prof.E.Glueckauf transport model of the osmotic desalting of porous membranes,the separation mechanism of charged NF membrane is proposed.Under attracted by the charged NF membrane and driven by the hydraulic pressure,an ion dragging its opposite ion together enters and permeats the pore as an ion-pair i.e.a salt molecule with the electrically neutral,or is rejected by the NF membrane as the same way,then the salt molecule dissociates into the hydrauted cation and hydrauted anion immediately at the product water side.The effects of the charge number of the cations or anions in the ion-pair(I.e.the salt molecule)on the separation performance of the charged NF membrane also are discussed.The concept of the ion apparent rejection is proposed,and the phenomenon that the ion apparent rejection can be a negative value is also explained.Finally,a new short and simple definition for technical terms of“nanofiltration membrane”and“nanofiltration”is recommended respectively.

关 键 词：荷电纳滤膜 分离机理 离子对 盐分子 静电吸引 静电排斥 电中性 离子的表观截留率 负截留率 

分 类 号：TQ028.8[化学工程]