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过程工程学报 ›› 2016, Vol. 16 ›› Issue (4): 706-713.DOI: 10.12034/j.issn.1009-606X.216167

• 材料工程专栏 • 上一篇    下一篇

载铁活性炭的制备及其吸附水溶液中铀离子的性能

杨灵芳1,刘峙嵘1,刘大前1,赖毅2   

  1. 1. 东华理工大学核工程与地球物理学院
    2. 东华理工大学化学生物与材料科学学院
  • 收稿日期:2016-03-29 修回日期:2016-09-21 出版日期:2016-08-20 发布日期:2016-10-10
  • 通讯作者: 刘峙嵘

Preparation of Fe-loaded Activated Carbon and Its Adsorption Property to Uranium Ion in Aqueous Solution

YANG Ling-fang 1,ZHU Xia-ping 2,LIU Da-qian 2,LAI Yi 2   

  1. 1. College of Nuclear Engineering and Geophysics, East China University of Technology
    2. College of Chemical, Biological and Material Science, East China Institute of Technology
  • Received:2016-03-29 Revised:2016-09-21 Online:2016-08-20 Published:2016-10-10
  • Contact: ZHU Xia-ping

摘要: 采用液相还原法制备载铁活性炭,对负载铁前后及吸附铀离子U(VI)后的活性炭进行表征,考察了其吸附性能. 结果表明,铁以球形疏散负载于活性炭的孔隙中,载铁后比表面积为10.3 m2/g,孔容为0.0245 cm3/g,最可几孔径为10.5 nm. 吸附U(VI)过程中铁表面发生腐蚀并形成新晶体,比表面积增至16.7 m2/g,孔容增至0.0955 cm3/g,最可几孔径增至17.9 nm. 载铁活性炭对水溶液中铀离子的吸附机理为吸附、氧化还原和沉淀. 在FeSO4?7H2O与活性炭质量比1.25/1、载铁活性炭投加量0.6 mg/mL、反应时间60 min及pH值5.00的条件下,水溶液中U(VI)的去除率最佳,达99.9%,U(VI)初始浓度和反应温度的影响较小. 载铁活性炭吸附U(VI)的过程符合Freundlich (R2=0.992)和Langmuir (R2=0.943)吸附等温模型,动力学过程符合准二级动力学模型(R2=0.999),扩散速率主要由液膜扩散控制.

关键词: 载铁活性炭, 铀离子, 去除率, 动力学, 等温线

Abstract: The Fe-loaded activated carbon was prepared by liquid-phase chemical reduction procedure. The activated carbon, Fe-loaded activated before and after adsorption uranium ion were analyzed, its absorption property to uranium ion was studied. The results showed that Fe was embedded loosely as spheres in the pores of activated carbon which had a specific surface area of 10.3 m2/g, pore size of 0.0245 cm3/g and pore diameter of 10.5 nm. Some erosion and new crystals on iron surface were detected after adsorption uranium ion, contributing a rise in specific surface area of 16.7 m2/g, pore size of 0.0955 cm3/g and pore diameter of 17.9 nm. Redox, together with adsorption and precipitate, dominant the uranium ion removal efficiency. The maximum removal rate was 99% with mass ratio of FeSO4?7H2O to activated carbon of 1.25:1, Fe-AC concentration of 0.6 mg/mL , reaction time of 60 min, and pH value of 5.00. The uranium ion adsorption by Fe-loaded activated carbon matched Langmuir (R2=0.943) and Freundich (R2=0.992) models. The adsorption reaction could be described by a pseudo-second order kinetics equation (R2=0.999), and diffusion rate agreed with the membrane diffusion.

Key words: Fe-loaded activated carbon, uranium ion, removal rate, kinetics, isotherm