title: [Study of adsorption and desorption of behaviors of Pb2+ on thiol-modified bentonite by flame atomic absorption spectrometry].
abstract: 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 C. 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 PbZ+; it is adapted to lead contaminated soil for chemical remediation.
authors.affiliation: Chengdu University of Technology, Chengdu, China. chenwen@cdut.cn
authors.forename: Wen
authors.initials: W
authors.lastname: Chen
authors.forename: Qiong-Xian
authors.initials: QX
authors.lastname: Xiong
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Pang
authors.forename: Xia-Ping
authors.initials: XP
authors.lastname: Zhu
authors.forename: Mei
authors.initials: M
authors.lastname: Han
authors.forename: Qiu-Xiang
authors.initials: QX
authors.lastname: Zhao
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Liu