纳滤膜及其在水处理中的应用

纳滤膜具有筛分效应和电荷效应两个显著特性,能截留大分子量有机物和多价离子,而允许小分子有机物和单价离子通过。对于纳滤膜的分离机理,提出了非平衡热力学模型、电荷模型、静电排斥和立体位阻模型。根据纳滤膜特有的性质,介绍了其在水处理领域包括水的软化、脱除饮用水中有害物质、废水处理三个方面的应用,并分析了纳滤膜污染的机理以及防止措施。

Nanofiltration membrane and its application in water treatment

Nanofiltration membrane has two important characteristics of electrostatic and steric-hindrance effects. It has the ability to retain high molecular weight organic substances and multivalent ions, and low molecular weight organic substances and monovalent ions can however pass through the membrane. In this paper, separation mechanisms of nanofiltration membrane was discussed, and the non-equilibrium thermodynamics model, the charge model, and the electrostatic and steric-hindrance model were put forward. According to the characteristics of nanofiltration membrane, its applications to water treatment, including water desalination, removing nocuous substances from drinking-water and wastewater treatment, were presented. The mechanisms of nanofiltration membrane fouling and its prevention measures were analyzed.