Efficient removal of heavy metal ions by forward osmosis membrane with a polydopamine modified zeolitic imidazolate framework incorporated selective layer.
Efficient removal of heavy metal ions by forward osmosis membrane with a polydopamine modified zeolitic imidazolate framework incorporated selective layer.
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DOI：
10.1016/j.jhazmat.2018.12.096
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发表时间：
2019-04
影响因子：
13.6
通讯作者：
Ming Qiu;Chunju He
中科院分区：
文献类型：
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作者：
Ming Qiu;Chunju He
一种新型薄膜纳米复合材料（TFN）正向渗透（FO）膜具有带正电和纳米功能选择层，可有效去除重金属离子。选择性层是通过聚多巴胺改性沸石咪唑酯骨架（ZIF-8@PDA）渗透到聚（乙烯亚胺）/1,3,5-苯三甲酰氯（PEI/TMC）交联基质中而构建的。与原始薄膜复合（TFC）膜相比，薄膜纳米复合膜（0.05 wt%纳米填料负载）在FO模式下表现出更高的水通量（20.8 vs12.8 LMH），且不损失Js/Jwratio（0.25 vs 0.20 g L−1）的选择性。渗透率的提高主要归功于优化的选择性层，具有良好的润湿性和疏松的结构。此外，修饰的PDA层促进了纳米填料和选择性层之间的亲和力，从而产生理想的选择性。此外，这种改性膜在 FO 模式下表现出较高的重金属离子（Cu2+、Ni2+ 和 Pb2+）截留率 (>96%)。我们的发现提供了一种简单有效的方法，通过设计用于处理重金属废水的选择性层来增强膜的 FO 性能。
A novel thin film nanocomposite (TFN) forward osmosis (FO) membrane with a positively charged and nano-functional selective layer has been developed for effective heavy metal ions removal. The selective layer is constructed by penetrating the polydopamine modified zeolitic imidazolate framework (ZIF-8@PDA) in the poly(ethyleneimine)/1,3,5-benzenetricarboxylic acid chloride (PEI/TMC) crosslinked matrix. Compared with the pristine thin film composite (TFC) membrane, the thin film nanocomposite membrane (0.05 wt % nanofillers loading) exhibits a higher water flux (20.8 vs12.8 LMH) without losing of selectivity in terms ofJs/Jwratio (0.25 vs 0.20 g L−1) in FO mode. This improvement of the permeability is mainly attributed to the optimized selective layer with good wettability and loose structure. Besides, the modified PDA layer facilitates the affinity between the nanofillers and selective layer, which results in an ideal selectivity. In addition, this modified membrane shows a high heavy metal ion (Cu2+, and Ni2+and Pb2+) rejection (>96%) in FO mode. Our finding offers a simple and efficient method to enhance the FO performance of membrane by designing the selective layer for treating heavy metal wastewater.