聚丙烯腈/羧基化碳纳米管纳米纤维膜制备及对铅离子的吸附效果

Preparation of Polyacrylonitrile/Carboxylated Carbon Nanotubes Nanofiber Membrane and its Adsorption Effect on Lead Ions

为此制备了一种聚丙烯腈(PAN)/羧基化多壁碳纳米管(MWCNTs-COOH)复合纳米纤维膜并探究其对废水中Pb^(2+)的吸附效果。将MWCNTs-COOH与PAN混合成溶液,通过静电纺丝技术,成功制备了PAN/MWCNTs-COOH复合纳米纤维膜;采用扫描电子显微镜观察其形貌;并在pH=3,5,7的条件下进行吸附实验,探究PAN/MWCNTs-COOH复合纳米纤维膜对Pb^(2+)吸附性能及吸附机理,用准一级和准二级动力学模型模拟吸附动力学进一步阐述实验数据;通过过滤吸附实验进一步研究PAN/MWCNTs-COOH复合纳米纤维膜在实际应用中对水中Pb^(2+)的清除性能。结果表明所制备的纳米纤维膜具有致密网状结构,形态良好;与pH=3,5条件下相比,在pH=7时,PAN/MWCNTs-COOH复合纳米纤维膜吸附性能最优,对Pb^(2+)吸附率达到70%及以上,并在80 min左右达到平衡;吸附动力学研究表明PAN/MWCNTs-COOH复合纳米纤维膜对Pb^(2+)可能是化学吸附;过滤实验显示PAN/MWCNTs-COOH复合纳米纤维膜对Pb^(2+)的吸附量高于空白对照纳米纤维膜(CON),呈现出优良过滤性能。

A polyacrylonitrile(PAN)/carboxylated multi-walled carbon nanotubes(MWCNTs-COOH)composite nanofiber membrane was prepared and its adsorption effect on Pb^(2+)in wastewater was investigated.The MWCNT-COOH and PAN were mixed into solution,and the PAN/MWCNTs-COOH composite nanofiber membrane was prepared by electrospinning technology.The morphology was observed by scanning electron microscope.Adsorption experiments were carried out at pH=3,5 and 7 to explore the adsorption performance and mechanism of lead ions on PAN/MWCNTs-COOH composite nanofiber membranes.The adsorption kinetics were simulated by quasi-first-order and quasi-second-order kinetic models to further elaborate the experimental data.Filtration adsorption experiments were conducted to further study the removal performance of lead ions in water by PAN/MWCNTs-COOH composite nanofiber membrane in practical application.The prepared nanofiber membrane have a dense network structure and good morphology.Compared with the conditions of pH=3 and 5,the adsorption performance of PAN/MWCNTs-COOH composite nanofiber membrane is the best at pH=7,and the adsorption rate of lead ions reaches 70%and above,and reaches equilibrium for about 80 min.The adsorption kinetics study indicates that PAN/MWCNTs-COOH composite nanofiber membrane may be chemically adsorbed for lead ions.Filtration experiments show that the adsorption capacity of PAN/MWCNTs-COOH composite nanofiber membrane for lead ions is higher than that of blank control nanofiber membrane(CON),showing excellent filtration performance.