用于混合一价盐分离的纳滤膜的制备及性能研究

This paper aims to develop new nanofiltration membranes that achieve high selectivity of CH₃COO^- and Cl^-, which is difficult to separate in pigment and other wastewater. Guided by the separation mechanism between the apparent activation energy and dehydration, 3,5-diaminobenzoic acid (DMA) was utilized to adjust the pore size, surface charge and other properties of a thin film composite (TFC) nanofiltration membrane. XPS results show that DMA participates in the interfacial polymerization reaction to form a loose selective layer; Zeta potential shows that the surface of the film is negatively charged. By tuning the pH, operating pressure, and other conditions, the optimized membrane [0.6%(mass) DMA-TFC] was obtained with the water flux 44% higher than that of the unmodified composite membrane, and the separation ratio of CH₃COO^- and Cl^- reached 15.0. This work provides a theoretical and practical basis for the design and preparation of nanofiltration membranes for similar ion separation. It shows great application prospects in the fields of water treatment such as pigment wastewater and material separation.