Chemical Industry and Engineering Progree

Previous Articles     Next Articles

Adsorption of tannic acid using organic montmorillonite

ZHOU Yan1,ZHANG Jianping2,3,LUO Xuegang2,LIN Xiaoyan2,XU Bijun1   

  1. 1 School of Chemistry and Chemical Engineering,Mianyang Normal University,Mianyang 621000,Sichuan,China;2 Engineering Research Center of Biomass Materials,Ministry of Education,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;3 The Eighth Research Institute,China Academy of Engineering Physics,Mianyang 621900,Sichuan,China
  • Online:2014-07-05 Published:2014-07-05

有机蒙脱土对单宁酸的吸附性能

周艳1,张建平2,3,罗学刚2,林晓艳2,许必军1   

  1. 1绵阳师范学院化学与化学工程学院,四川 绵阳 621000;2西南科技大学生物质材料教育部工程研究中心,四川 绵阳 621010;3中国工程物理研究院第八研究所,四川 绵阳 621900

Abstract: Organic montmorillonite (OMMT) modified by hydroxyethylhexadecyldimethyl ammonium bromine was prepared through cation exchange with natural montmorillonite(MMT). Material characterizations before and after the modification were investigated using X-ray diffraction and Fourier transform-infrared (FT-IR) spectroscopy. Batch static experiments of OMMT for tannic acid (TA) were performed on adsorption conditions and mechanism. The adsorption process was strongly pH-dependent and the optimal pH value was 4.0. Adsorption equilibrium was reached at 6 h and the adsorption process followed pseudo-second-order kinetics. The adsorption isotherm was better described by the Langmuir isotherm equations compared to the Freundlich isotherm equations. The maximum adsorption capacity obtained was 181.6 mg/g at pH of 4 when initial TA concentration was 500 mg/L and temperature was 293 K. The thermodynamic parameters of ΔG and ΔH were negative,revealing that the adsorption of TA onto OMMT was a spontaneous and endothermic process. The adsorption capacity of the regenerated OMMT decreased by less than 20% after alternating between saturating adsorption and desorption of TA for seven times.

Key words: organic montmorillonite (OMMT), adsorption, tannic acid (TA), kinetics, thermodynamics

摘要: 利用十六烷基二甲基羟乙基溴化铵对钠基蒙脱土(MMT)进行离子交换改性,制得有机蒙脱土(OMMT),并通过FT-IR、XRD对MMT改性前后的结构进行表征。通过静态吸附试验,探究OMMT对单宁酸(TA)的吸附条件和吸附机理。结果表明,OMMT吸附TA对pH值有较大的依赖性,吸附最佳pH值在4.0左右;吸附平衡时间为6h,吸附动力学曲线符合准二级动力学模型;吸附等温线用Langmuir方程比Freundlich方程能更好地描述;在pH值为4.0、TA初始浓度为500 mg/L、温度为20℃时,最大吸附容量为181.6mg/g;热力学参数ΔG、ΔH均为负值表明吸附为自发的放热过程。在饱和吸附和解吸重复7次后,再生OMMT吸附容量下降不到20%。

关键词: 有机蒙脱土, 吸附, 单宁酸, 动力学, 热力学

京ICP备12046843号-2;京公网安备 11010102001994号
Copyright © Chemical Industry and Engineering Progress, All Rights Reserved.
E-mail: hgjz@cip.com.cn
Powered by Beijing Magtech Co. Ltd