高等学校化学学报

高等学校化学学报 ›› 2010, Vol. 31 ›› Issue (1): 135.

• 研究论文 • 上一篇    下一篇

纳米γ-Al2O3吸附Ge(Ⅳ)的机理及性能

张蕾, 李红梅, 韩光喜, 康平利   

  1. 辽宁大学化学学院, 沈阳 110036
  • 收稿日期:2009-04-08 出版日期:2010-01-10 发布日期:2010-01-10
  • 通讯作者: 张蕾, 女, 博士, 教授, 主要从事稀散元素分离富集研究. E-mail: zhanglei63@126.com
  • 基金资助:

    辽宁省教育厅科创新团队项目(批准号: 2007T053)和辽宁省自然科学基金(批准号: 20082049)资助.

Adsorption Behavior and Mechanism of Nano-Al2O3 for Ge(Ⅳ)

ZHANG Lei*, LI Hong-Mei, HAN Guang-Xi, KANG Ping-Li   

  1. College of Chemistry, Liaoning University, Shenyang 110036, China
  • Received:2009-04-08 Online:2010-01-10 Published:2010-01-10
  • Contact: ZHANG Lei. E-mail: zhanglei63@126.com
  • Supported by:

    辽宁省教育厅科创新团队项目(批准号: 2007T053)和辽宁省自然科学基金(批准号: 20082049)资助.

PDF (PC)

摘要：

研究了纳米γ-Al2O3吸附剂对Ge(Ⅳ)的吸附行为, 考察了吸附平衡时间、温度和溶液的pH值等因素对吸附过程的影响. 结果表明, 纳米Al2O3对Ge(Ⅳ)的吸附在2 min时基本达到平衡, 在pH=4~11范围内, Ge(Ⅳ)可以被纳米Al2O3定量富集, 吸附率大于95%; 吸附于纳米Al2O3上的Ge(Ⅳ)可以用 0.3 mol/L K3PO4和1 mol/L H2SO4混合溶液洗脱, 5 min后基本达到解析平衡, 解析率能达到97%; 该吸附过程符合准二级反应动力学模型, 计算了不同温度下的吸附速率常数, 并求得纳米Al2O3对Ge(Ⅳ)的吸附活化能(Ea)为11.63 kJ/mol; 该体系的吸附过程符合Freundlich等温式, 由D-R等温式求得常温下纳米Al2O3对Ge(Ⅳ)的平均吸附能为10.87 kJ/mol. Ge(Ⅳ)吸附反应的ΔG0为负值, 焓变ΔH0为正值, 说明该吸附过程是自发的吸热反应.

关键词: Ge(Ⅳ); 纳米γ-Al2O3; 吸附; 动力学; 热力学

Abstract:

The effects of various equilibrium time, temperature and pH on the adsorption of Ge(Ⅳ) on nano-Al2O3 were studied. The results show that the adsorption is fast to reach equilibrium within 2 min. It was found that the adsorption efficiency of Ge(Ⅳ) was more than 95% with pH from 4 to 11. Almost all of Ge(Ⅳ) ions adsorpted onto nano-Al2O3 can be eluted with 0.3 mol/L K3PO4-1 mol/L H2SO4 mixed solution within 5 min, the desorption percentage can reach 97%. The sorption of Ge(Ⅳ) ions onto nano-Al2O3 followed the second-order rate equation, the kinetic experimental data properly correlate with the second-order kinetic model and the values of activation energy(Ea) was 11.63 kJ/mol. The adsorption data are fitted to the Freundlich and the magnitude of sorption energy computed from D-R equation is 10.87 kJ/mol, thus, the type of the adsorption of germanium on nano-Al2O3 is a chemical adsorption. The ΔG0 and ΔH0 values is negative and positive respectively which indicate the adsorption of Ge(Ⅳ) on nano-Al2O3 is spontaneous and endothermic.

Key words: Ge(Ⅳ); Nano-γ-Al2O3; Adsorption; Kinetics; Thermodynamic

TrendMD: