MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, PR China.
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, PR China.
J Hazard Mater. 2017 Sep 5;337:217-225. doi: 10.1016/j.jhazmat.2017.04.032. Epub 2017 Apr 12.
The dye wastewater is one of the most difficult industrial wastewaters to treat. It keeps a big challenge to realize fast removal of dyes from water by membrane filtration due to the trade-off between separation selectivity and permeation flux for ultrafiltration or nanofiltration (NF) process. Here we report novel composite porous membranes which can remove anionic dyes from water by ultrafast permeating adsorption. A crosslinked polyethyleneimine (PEI) polymer with strong adsorption ability was incorporated onto a nylon microfiltration membrane by the interfacial amidation reaction between PEI and trimesoyl chloride. The obtained composite membranes were used for the decolorization of dye solution by permeation mode. It was shown that the composite membranes were able to nearly completely remove anionic dyes in acidic conditions with high permeation fluxes. In an optimized case, the adsorption capacity of Sunset Yellow for the composite membranes reached 0.7mg/cm with a high flux of 85L/mh under a ultralow pressure of 0.01bar. This flux was far much higher than that of NF membranes, about 10L/mhbar. The pH-dependent electrostatic interaction between PEI and anionic dyes was responsible for the rapid dye removal. The adsorption saturated membranes could be effectively regenerated by a simple alkaline washing.
染料废水是最难处理的工业废水之一。由于超滤或纳滤 (NF) 过程的分离选择性和渗透通量之间存在权衡，因此通过膜过滤实现染料的快速去除仍然是一个巨大的挑战。在这里，我们报告了一种新型复合多孔膜，它可以通过超快渗透吸附去除水中的阴离子染料。通过 PEI 和均苯三甲酰氯之间的界面酰胺化反应，将具有强吸附能力的交联聚乙烯亚胺 (PEI) 聚合物掺入尼龙微滤膜中。所得复合膜用于通过渗透模式对染料溶液进行脱色。结果表明，在酸性条件下，复合膜能够以高渗透通量几乎完全去除阴离子染料。在优化条件下，复合膜对日落黄的吸附容量达到 0.7mg/cm，在超低压力 0.01bar 下的通量高达 85L/mh。该通量远高于 NF 膜，约为 10L/mhbar。PEI 和阴离子染料之间的 pH 依赖性静电相互作用是快速去除染料的原因。吸附饱和的膜可以通过简单的碱性洗涤有效地再生。
