原子吸收光谱法研究巯基改性膨润土对Pb^(2＋)的吸附解吸  

Study of Adsorption and Desorption of Behaviors of Pb^(2+) on Thiol-Modified Bentonite by Flame Atomic Absorption Spectrometry

作　　者：陈文[1,2] 熊琼仙[1] 庞小峰[2] 朱霞萍[1] 韩梅[1] 赵秋香[3] 刘文华[3] 

机构地区：[1]成都理工大学材料与化学化工学院,四川省矿产资源化学高校重点实验室,四川成都610059 [2]电子科技大学生命科学与技术学院,四川成都610054 [3]广东省物料实验检测中心,广东广州510080

出　　处：《光谱学与光谱分析》2013年第3期817-821,共5页Spectroscopy and Spectral Analysis

基　　金：国家(973计划)项目(2011CB503700);广东省财政厅地质专项(2011208);横向委托项目(HP0030和HG0103)资助

摘　　要：通过红外光谱(FTIR)法和扫描电镜(SEM)对钙基和巯基改性膨润土的官能团和表面结构进行了比较分析,以火焰原子吸收光谱法(FAAS)为检测手段,研究了巯基改性膨润土对Pb2+吸附的影响因素并优化了吸附条件,讨论了模拟酸雨解吸Pb2+的条件。比较了钙基和巯基改性膨润土作为吸附剂对水溶液中Pb2+的吸附、固定能力。研究表明:25℃下,吸附时间为60min、离子强度为0.1mol.L-1的KNO3、pH6.0时,5.0g.L-1巯基改性膨润土对100mg.L-1的Pb2+的吸附率达到98%以上,平衡吸附量达到67.27mg.g-1,吸附能力明显优于钙基膨润土(9.667mg.g-1),吸附过程符合Langmuir和Freundlich等温线方程。用pH 3.50的极限酸度模拟酸雨进行解吸,解吸率为0。表明该巯基改性膨润土对Pb2+具有很强的吸附、固定能力,适于重金属铅污染土壤中铅的吸附固定修复之用。A comparative analysis of the functional groups and surface structure of the Ca-bentonite（RB） and thiol-modified bentonite（TMB） were characterized by means of FTIR and SEM.The absorptive property of Pb2＋ on TMB and RB and its influential factors was studied and the conditions for the adsorption were optimized by using FAAS method.Then the conditions for desorption of Pb2＋ from the TMB by using simulated acid rain were studied and the contrast analysis of absorptive stability of Pb2＋ on TMB and RB was given.The results showed that the adsorption rate of Pb2＋ by TMB could reach more than 98%,when the initial Pb2＋ concentration was 100 mg·L-1,the liquid-solid ratio was 5 g·L-1,pH was 6.0,KNO3 ionic strength was 0.1 mol·L-1 and adsorption period was 60min at 25 ℃.The saturated adsorption capacity of TMB was 67.27 mg·g-1;it＇s much more than that of RB（9.667 mg·g-1）.The adsorption of Pb2＋ on TMB follows Langmuir and Freundlich isotherm models well.Desorption experiments of Pb2＋ from TMB with simulated acid rain（pH 3.50） were done,and the desorption rate was 0.The results showed that TMB has a strong adsorption and fixation capacity for Pb2＋;it is adapted to lead contaminated soil for chemical remediation.

关 键 词：巯基改性膨润土 吸附 解吸 铅离子 

分 类 号：TD985[矿业工程—选矿] X703[环境科学与工程—环境工程]