Novel nanofiltration membranes consisting of a sulfonated pentablock copolymer rejection layer for heavy metal removal.
Novel nanofiltration membranes consisting of a sulfonated pentablock copolymer rejection layer for heavy metal removal.
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DOI：
10.1021/es5031239
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发表时间：
2014-11
影响因子：
11.4
通讯作者：
Zhiwei Thong;G. Han;Yue Cui;Jie Gao;T. Chung;S. Chan;Shawn Wei
中科院分区：
文献类型：
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作者：
Zhiwei Thong;G. Han;Yue Cui;Jie Gao;T. Chung;S. Chan;Shawn Wei
面对含重金属离子的废水排放的严格规定，各个行业都需要更高效和有效的处理方法。在现有的方法中，纳滤（NF）是一种可行且有前途的选择。然而，新的膜材料的开发是不断需要的，以促进这一技术的进步。这是第一次尝试开发一种复合纳滤膜，包括分子设计的五嵌段共聚物选择性层，用于去除重金属离子的报告。所得NF膜具有0.50 nm的平均有效孔径、255 Da的截留分子量和2.4 LMH/bar的相当高的纯水渗透率（A）。新开发的纳滤膜可有效去除重金属离子如Pb（2+）、Cd（2+）、Zn（2+）和Ni（2+），截留率> 98.0%。另一方面，该膜对HAsO 4（2-）（99.9%）和HCrO 4（-）（92.3%）等阴离子也显示出相当高的截留率。这种性能可归因于（1）五嵌段共聚物形成具有限定孔径的连续水输送通道的独特能力和（2）在选择性层和基底之间引入聚乙烯亚胺作为沟槽层。据我们所知，这是首次报道的NF膜包含这种五嵌段共聚物作为选择性材料。在这项研究中取得的有希望的初步结果提供了一个有用的平台，开发新的纳滤膜去除重金属。
Facing stringent regulations on wastewater discharge containing heavy metal ions, various industries are demanding more efficient and effective treatment methods. Among the methods available, nanofiltration (NF) is a feasible and promising option. However, the development of new membrane materials is constantly required for the advancement of this technology. This is a report of the first attempt to develop a composite NF membrane comprising a molecularly designed pentablock copolymer selective layer for the removal of heavy metal ions. The resultant NF membrane has a mean effective pore diameter of 0.50 nm, a molecular weight cutoff of 255 Da, and a reasonably high pure water permeability (A) of 2.4 LMH/bar. The newly developed NF membrane can effectively remove heavy metal cations such as Pb(2+), Cd(2+), Zn(2+), and Ni(2+) with a rejection of >98.0%. On the other hand, the membrane also shows reasonably high rejections toward anions such as HAsO4(2-) (99.9%) and HCrO4(-) (92.3%). This performance can be attributed to (1) the pentablock copolymer's unique ability to form a continuous water transport passageway with a defined pore size and (2) the incorporation of polyethylenimine as a gutter layer between the selective layer and the substrate. To the best of our knowledge, this is the first reported NF membrane comprising this pentablock copolymer as the selective material. The promising preliminary results achieved in this study provide a useful platform for the development of new NF membranes for heavy metal removal.