中华医学超声杂志

应用化学 ›› 2010, Vol. 27 ›› Issue (02): 142-146.DOI: 10.3724/SP.J.1095.2010.90101

• 研究论文 • 上一篇    下一篇

MgAl无机-有机杂化材料对Pb2+的吸附

张树芹1*,侯万国2,路福绥1,李丽芳1,姜林1   

  1. (1.山东农业大学化学学院 泰安 271018;2.青岛科技大学化学与分子工程学院 青岛)
  • 收稿日期:2009-02-16 修回日期:2009-05-29 出版日期:2010-02-10 发布日期:2010-02-10
  • 通讯作者: 张树芹，女，博士，副教授; E-mail:zsqtaian@sdau.edu.cn; 研究方向：重金属污染生态修复
  • 基金资助:
    国家重大基础研究(“九七三”)计划(2004CB418504) 国家自然科学基金(20573065)和山东省自然科学重点基金(Z2005B02)资助项目

Adsorption of Pb2+ on LDHs and EDTA-LDHs Nanohybrid

ZHANG Shu-Qin1*, HOU Man-Guo2, LU Fu-Rui1, LI Li-Fang1, JIANG Lin1   

  1. (1.College of Chemistry and Material Science,Shandong Agriculture University,Taian 271018;
    2.College of Chemistry and molecular engineering,Qingdao University of Science Technology,Qingdao)
  • Received:2009-02-16 Revised:2009-05-29 Published:2010-02-10 Online:2010-02-10

PDF

1425

被引次数

6

摘要：

采用共沉淀法合成了结晶度良好、具有纯水滑石相的Mg-Al型层状双金属氢氧化物(LDH)及其乙二胺四乙酸二钠(EDTA)-LDH无机有机杂化物, 并进行了表征。 考察了Mg-Al LDH和EDTA-LDH对Pb2+的吸附作用,其均有很好的吸附能力，EDTA在LDH通道中可能以直立平行方式排列成单层。 在相同条件下,EDTA-LDH的吸附速率和吸附量均高于Mg-Al LDH。 结果表明 ，EDTA的插入具有协同增效作用， 吸附动力学符合准二级吸附速率方程。 吸附等温线可分为吸附阶段和表面沉淀阶段，吸附阶段的等温线符合Freundlich吸附等温式。 初始pH值对Pb2+的吸附基本无影响。 Pb2+在LDH和EDTA-LDH上的吸附机理主要为表面沉淀,并存在化学键合和静电键合作用,EDTA-LDH存在EDTA与Pb2+的络合作用。

关键词: MgAl无机-有机杂化材料，乙二胺四乙酸二钠，Pb2+，吸附

Abstract:

Well crystalled MgAl-layered double hydroxide(MgAl-LDH) and EDTA-LDH nanohybrids were synthesized via a co-precipitation method and characterized. The ligand EDTA is probably accommodated in vertical position in the interlayer space of LDH. The sorption behavior of MgAl-LDH and EDTA-LDH nanohybrids for lead ions was also investigated as a function of concentration, pH and time. It is found that both of them show good sorption ability for Pb2+. The sorption rate and the equilibrium sorption amount of Pb2+ are higher on EDTA-LDH nanohybrids than on MgAl-LDH under identical conditions, which indicate the intercalation of EDTA exhibits synergy. The sorption can be described by the pseudo-second order kinetics. The sorption occurrs in two steps, an adsorption process followed by surface precipitation. The adsorption isotherms are well fitted to Freundlich isotherm. Within the experimental concentration range, the variation of adsorbed amount is not obvious with the variation of pH because of the compound having a property of buffering pH(buffering pH effect).

Key words: layered double hydroxide,EDTA,lead,adsorption

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