当前位置: X-MOL 学术Environ. Sci. Technol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Planting Anion Channels in a Negatively Charged Polyamide Layer for Highly Selective Nanofiltration Separation
Environmental Science & Technology ( IF 11.4 ) Pub Date : 2022-11-29 , DOI: 10.1021/acs.est.2c06582
Yuling Ren 1 , Pengfei Qi 2 , Yinhua Wan 1, 3 , Chulong Chen 4 , Xiangrong Chen 1 , Shichao Feng 1 , Jianquan Luo 1
Affiliation  

A nanofiltration (NF) membrane with high salt permeation and high retention of small organics is appealing for the treatment of high-salinity organic wastewater. However, the conventional negatively charged NF membranes commonly show high retention of divalent anions (e.g., SO42–), and the reported positively charged NF membranes normally suffer super low selectivity for small organics/Na2SO4 and high fouling potential. In this work, we propose a novel “etching–swelling–planting” strategy assisted by interfacial polymerization and mussel-inspired catecholamine chemistry to prepare a mix-charged NF membrane. By X-ray photoelectron spectroscopy depth profiling and pore size distribution analysis, it was found that such a strategy could not only deepen the positive charge distribution but also narrow the pore size. Molecular dynamics confirm that the planted polyethyleneimine chains play an important role to relay SO42– ions to facilitate their transport across the membrane, thus reversing the retention of Na2SO4 and glucose (43 vs 71%). Meanwhile, due to the high surface hydrophilicity and smoothness as well as the preservation of abundant negatively charged groups (−OH and −COOH) inside the separation layer, the obtained membrane exhibited excellent antifouling performance, even for the coking wastewater. This study advances the importance of vertical charge distribution of NF membranes in separation selectivity and antifouling performance.

中文翻译:

在带负电的聚酰胺层中植入阴离子通道以实现高选择性纳滤分离

纳滤 (NF) 膜具有高盐渗透和小有机物的高截留能力,可用于处理高盐度有机废水。然而,传统的带负电荷的纳滤膜通常对二价阴离子(例如 SO 4 2– )表现出高保留能力,而报道的带正电荷的纳滤膜通常对小有机物/Na 2 SO 4具有超低的选择性和高污染潜力。在这项工作中,我们提出了一种新的“蚀刻-溶胀-种植”策略,通过界面聚合和受贻贝启发的儿茶酚胺化学辅助制备混合电荷纳滤膜。通过X射线光电子能谱深度剖析和孔径分布分析,发现这种策略不仅可以加深正电荷分布,还可以缩小孔径。分子动力学证实,植入的聚乙烯亚胺链在中继 SO 4 2-离子以促进其跨膜运输方面发挥重要作用,从而逆转 Na 2 SO 4的保留和葡萄糖(43% 对 71%)。同时,由于高表面亲水性和光滑性以及分离层内部保留了丰富的负电荷基团(-OH和-COOH),所获得的膜即使对焦化废水也表现出优异的防污性能。本研究提出了纳滤膜垂直电荷分布在分离选择性和防污性能中的重要性。
更新日期:2022-11-29
down
wechat
bug