Zhang Hong-Li, Cai Huaqiang, Xia Yu, Zhang Pan, Xiong Si-Wei, Gai Jing-Gang
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University Chengdu Sichuan 610065 P. R. China
Institute of Chemical Materials, China Academy of Engineering Physics Mianyang 621900 P. R. China.
RSC Adv. 2020 Jan 21;10(6):3438-3449. doi: 10.1039/c9ra09380j. eCollection 2020 Jan 16.
Considerable efforts are being made to develop new materials and technologies for the efficient and fast removal of toxic ions in drinking water. In this work, we developed a sulfur-complexed strategy to enhance the removal capability of heavy metal ions using the polyamide nanofiltration membrane by the covalent anchoring of l-cystine and l-cysteine. The sulfur-functionalized polyamide nanofiltration membrane exhibits superior complexation of heavy metal ions and can efficiently remove them from high-concentration wastewater. As a result, the sulfur-functionalized nanofiltration membrane not only showed excellent desalination performance but also achieved a record removal rate of heavy metal ions (99.99%), which can effectively reduce Hg(ii) concentration from 10 ppm to an extremely low level of 0.18 ppb, well below the acceptable limits in drinking water (2 ppb). Moreover, the sulfur-functionalized nanofiltration membrane showed an exciting long-term stability and can be easily regenerated without significant loss of Hg(ii) removal efficiency even after six cycles. Such outstanding performances were attributed to the synthetic effect of Hg-S coordinative interaction, electrostatic repulsion, and the sieving action of nanopores. These results highlight the tremendous potential of thiol/disulfide-functionalized NF active layer as an appealing platform for removing heavy metal ions from polluted water with high performance in environmental remediation.
人们正在付出巨大努力来开发新材料和技术，以高效快速地去除饮用水中的有毒离子。在这项工作中，我们开发了一种硫络合策略，通过L-胱氨酸和L-半胱氨酸的共价锚定，利用聚酰胺纳滤膜提高重金属离子的去除能力。硫功能化聚酰胺纳滤膜对重金属离子具有优异的络合能力，能够从高浓度废水中高效去除重金属离子。结果，硫功能化纳滤膜不仅表现出优异的脱盐性能，还实现了重金属离子的创纪录去除率（99.99%），能有效将Hg(ii)浓度从10 ppm降低到极低的0.18 ppb，远低于饮用水的可接受限值（2 ppb）。此外，硫功能化纳滤膜表现出令人兴奋的长期稳定性，即使经过六个循环后，也能轻松再生，且Hg(ii)去除效率无显著损失。这些出色的性能归因于Hg-S配位相互作用、静电排斥和纳米孔筛分作用的综合效果。这些结果突出了硫醇/二硫键功能化纳滤活性层作为一个极具吸引力的平台在环境修复中高效去除污染水中重金属离子的巨大潜力。
