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›› 2012, Vol. 12 ›› Issue (4): 590-595.

• 反应与分离 • Previous Articles     Next Articles

Adsorption Kinetics of Friedel's Salt for Removal of Cd2+ from Low Concentration Wastewater

ZHANG Juan-juan ZHAO He CAO Hong-bin LI Zhi-bao   

  1. College of Chemical and Biologic Engineering, Changsha University of Science and Technology College of Chemical and Biologic Engineering, Changsha University of Science and Technology Institute of Processing Engineering ，CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences
  • Received:2012-05-28 Revised:2012-07-09 Online:2012-08-20 Published:2012-08-20
  • Contact: ZHANG Juan-juan

Friedel盐对废水中低浓度Cd2+的吸附动力学

张娟娟 赵赫 曹宏斌 李志宝   

  1. 长沙理工大学化学与生物工程学院 长沙理工大学化学与生物工程学院 中国科学院过程工程研究所 中国科学院过程工程研究所绿色过程与工程重点实验室
  • 通讯作者: 张娟娟

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Abstract: The kinetics and adsorption isotherms of Cd2+ removal from wastewater with Friedel's salt (FS, 3CaO×A12O3×CaCl2×10H2O), as adsorbent were investigated. The influences of FS dosage, temperature and initial Cd2+ concentration were examined. The results showed that the removal rate of Cd2+ from initial concentration (10 mg/L) wastewater was up to 94.34% with the adsorption capacity of 301.9 mg/g when FS dosage was 0.03 g/L. The basic adsorption mechanism was ion exchange. Finally, Cd2+ in the water existed in the form of complexes as Cd4Al2(OH)12Cl2(H2O)4×xH2O and Cd4Al2(OH)12Cl2×4H2O. Pseudo-?rst-order model was applied to correlate adsorption reaction data, adsorption rate constant k was obtained with the value of 0.049 min-1. The Langmuir isotherm equation suitably fitted to the adsorption isotherm data.

Key words: Friedel's salt, Cd2+, adsorption, kinetics

摘要： 以合成的Friedel盐(FS, 3CaO×A12O3×CaCl2×10H2O)为吸附剂，研究了FS去除废水中Cd2+的反应动力学和等温吸附特性. 考察了FS盐用量、温度及Cd2+初始浓度对Cd2+去除的影响. 结果表明，FS用量为0.03 g/L时，在室温下对废水中初始浓度为10 mg/L的Cd2+的去除率大于94.34%，吸附容量可达301.9 mg/g，吸附主要以离子交换吸附为主，最终形成Cd4Al2(OH)12Cl2(H2O)4×xH2O及Cd4Al2(OH)12Cl2×4H2O化合物. 利用一级动力学模型关联了反应动力学数据，得到速率常数k=0.049 min-1，吸附行为较符合Langmuir等温吸附方程.

关键词: Friedel盐, Cd2+, 吸附, 动力学

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