化学学报 ›› 2009, Vol. 67 ›› Issue (13): 1509-1514. 上一篇    下一篇

研究论文

氨基功能化纳米Fe3O4磁性高分子吸附剂对废水中Cr(VI)的吸附研究

赵永纲a,b 沈昊宇*,a 李 勍a 夏清华c

  

  1. (a浙江大学宁波理工学院 宁波 315100)
    (b浙江大学理学院 杭州 310027)
    (c有机功能分子合成与应用教育部重点实验室(湖北大学) 武汉 430062)

  • 投稿日期:2008-10-13 修回日期:2008-12-19 发布日期:2009-07-14
  • 通讯作者: 沈昊宇

Adsorption Studies on Cr(VI) in Wastewater by NH2-functionalized Nano-Fe3O4 Magnetic Composites

Zhao, Yonggang a,b Shen, Haoyu *,a Li, Qing a Xia, Qinghua c

  

  1. (a Ningbo Institute of Technology, Zhejiang University, Ningbo 315100)
    (b College of Science, Zhejiang University, Hangzhou 310027)
    (c Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, School of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062)
  • Received:2008-10-13 Revised:2008-12-19 Published:2009-07-14
  • Contact: Shen, Haoyu

采用分散聚合法通过共聚、开环反应, 对纳米Fe3O4进行表面功能化修饰, 得到富含NH2官能团的纳米磁性高分子复合材料. 通过透射电镜(TEM)、振动样品磁强计(VSM)、热重差热分析(TGA)、X射线衍射(XRD)、红外光谱(IR)等对其进行表征, 着重研究了其作为吸附剂对Cr(VI)的吸附性能. 结果表明: 该吸附剂对Cr(VI)的吸附能在10 min内达到平衡; 废水溶液pH值能显著影响吸附剂对Cr(VI)的吸附效果, pH为2.5时效果最佳. 废水中Cr(VI)的初始浓度、吸附时间、温度等因素对吸附效果均有不同程度的影响. 结合相应pH值下Cr(VI)的形态分布, 探讨了这种新型材料对Cr(VI)的吸附机理. 结果表明: 其吸附机理及吸附容量与废水中Cr(VI)的离子形式有关; 吸附过程以离子交换与静电引力为主. 等温吸附数据符合Langmuir模型, T=308 K, pH=2.5, V=40 mL时, 吸附剂的饱和吸附容量qm=25.58 mg/g. 吸附为吸热过程, 焓变ΔH=8.64 kJ/mol.

关键词: 功能化纳米Fe3O4, Cr(VI), 吸附原理, Langmuir模型

A novel nano-sized magnetic polymer adsorbent coupled with ethylenediamine has been obtained via co-polymerization and ring-opening reactions, followed by chemical co-precipitation for the preparation of Fe3O4. The adsorbent was characterized by TEM, VSM, TGA, XRD, FTIR, etc. Its application to the adsorption of Cr(VI) from wastewater was also investigated. The results showed that the adsorption capability was affected by pH, the initial concentration of Cr(VI), the adsorption time and temperature. With the distributions of Cr(VI) species in function of pH under corresponding conditions, the adsorption mechanisms of Cr(VI) including both ion exchange and electrostatic gravitation were discussed. The adsorption of Cr(VI) reached equilibrium rapidly within 10 min. The adsorption data were well fitted with the Langmuir isotherm. The maximum sorption capacity of adsorbent to Cr(VI) calculated from the Langmuir isotherm was 25.58 mg/g at 308 K, pH 2.5 with volume of 40 mL. The adsorption was an endothermic process with the enthalpy deviation ΔH at 8.64 kJ/mol.

Key words: functionalized nano-Fe3O4, Cr(VI), adsorption principle, Langmuir isotherm