有机蒙脱土对单宁酸的吸附性能.pdf

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化工进展
2014年第33卷第7期
CHEMICAL INDUSTRY AND ENGINEERING PROGRESS
1919
研究开发
MDAOA-2
有机蒙脱土对单宁酸的吸附性能
周艳,张建平23,罗学刚2,林晓艳2,许必军
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)
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,吸附动力学曲绒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値为4.0、TA初始浓度为S00mg几L、温度为20℃时,最大吸附容量为181.6mgg;热力学参数△G
△H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
中图分类号:X592;TQ949文献标志码:A文章编号:1000-6613(2014)07-1919-06
DOI:10.3969/.issn.1000-6613.2014.07.044
Adsorption of tannic acid using organic montmorillonite
ZHOU Yan ZHANG Jianping, LUO hegang LN Xiaoyan, XU Bijun
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; The Eighth Research Institute, China Academy of Engineering
Physics, Mianyang 621900, Sichuan, China)
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 AG and A 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
收稿日期:2013-12-23:修改稿日期:2014-02-18。
第一作者及联系人:周艳(1975-),女,硕士,副教授。E-mail
基金项目:四川省教育厅自然科学研究项目(13ZB0124)
zipzy@126.com