PEI改性碳纳米管吸附水溶液中的六价铬离子

摘要

实验以聚乙烯亚胺(PEI)改性碳纳米管为吸附剂除去水溶液中的Cr(VI).系统考察了溶液pH,吸附剂用量,吸附时间,温度等因素对吸附行为的影响.实验表明:25 ℃时,pH为2.85时吸附效果最佳,60 min内可达到吸附平衡.准二级模型可很好的描述吸附动力学过程.吸附等温线和吸附热力学研究表明,改性碳纳米管吸附Cr(VI)遵循Freundlich等温模型.%In the experiment,polyethyleneimine(PEI) is chosen to modify carbon nanotubes as an absorbent to get rid of Cr(VI) in aqueous solution.A systematic investigation is conducted on its absorption properties of Cr(VI) under the influence of factors like pH of aqueous solution,contact time, temperature,and dosage and so on.It is revealed that the optimal pH for the absorption is about 2.85 under which the absorption process reaches equilibrium in about 60 min.The absorption kinetics in its process is better described by Pseudo-second-order model.Absorption isotherm and absorption thermodynamic calculation shows that the absorption process of Carbon Nanotubes modified follows Langmuir isotherm model.