It is extremely important to realize the separation of dyes and salts in textile wastewater. The nanofiltration membranes with high hydrophilic surface and loose structure are the best choice for efficient dye/salt separation. Herein, the ultrafiltration substrate membrane is firstly prepared employing polyimides as raw material and nanodiamonds grafted by polyethyleneimine as additive. Then tannic acid and Fe3+ are introduced to assemble into metal-polyphenol networks, finally achieving the construction of loose nanofiltration membrane. The experimental results show that as-obtained nanofiltration membrane possesses excellent mechanical properties and delivers a pure water flux of 42.57 L m-2 h-1, which is twice that of nanofiltration membrane without nanodiamonds. The as-obtained nanofiltration membrane also showed effective dye/salt separation with high dye rejection (CR, 99.03 %) and low inorganic salt rejection (NaCl, 4.13 %). The flux recovery rate of the membrane to humic acid is as high as 96.50 %, and it has considerable antifouling performance.

中文翻译：

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通过胺离子功能化纳米金刚石设计松散的纳滤膜，以实现高效的染料/盐分离


实现纺织废水中染料和盐类的分离极为重要。纳滤膜具有高亲水表面和松散结构，是高效染料/盐分离的最佳选择。在此，首先以聚酰亚胺为原料，以聚乙烯亚胺为添加剂接枝纳米金刚石制备了超滤基底膜。然后引入单宁酸和 Fe ³⁺ 组装成金属-多酚网络，最终实现松散纳滤膜的构建。实验结果表明，所获得的纳滤膜具有优异的力学性能，可提供 42.57 L m ^-2 h ^-1 的纯水通量，是不含纳米金刚石的纳滤膜的两倍。所获得的纳滤膜还显示出有效的染料/盐分离，具有高染料截留率 （CR， 99.03 %） 和低无机盐截留率 （NaCl， 4.13 %）。膜对腐植酸的助焊剂回收率高达 96.50 %，具有相当的防污性能。