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.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
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
关键词
巯基改性膨润土
吸附
解吸
铅离子
Thiol-modified benfonite
Adsorption
Desoprtion
Lead ion
