Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7788060 | Carbohydrate Polymers | 2015 | 27 Pages |
Abstract
In this study, the Ag+-imprinted chitosan gel beads were synthesized to selectively adsorb Ag+ from bimetallic aqueous solutions containing the same molar concentration of Ag+ and Cu2+. The Ag+-imprinting not only helps to achieve extremely high selectivity of Ag+, but also enhances the uptake capacity of the target Ag+ by protecting some amine groups, the primary binding sites of metal ions from cross-linking. The maximum uptake of Ag+ by the ion-imprinted chitosan beads was found to be 89.20 mg gâ1 at 25.0 °C with an initial Ag+ concentration of 352.95 mg Lâ1 and the biosorbent dosage of 1.0 g Lâ1. The adsorption equilibrium and kinetics of Ag+ by the ion-imprinted chitosan beads can be better described by Langmuir isotherm and the intraparticle diffusion model. FTIR and XPS analyses suggested that amine functional groups involve the binding of Ag+ via complexation at higher solution pH (3.0 â¤Â pH â¤Â 5.0) and ion exchange at lower solution pH (1.0 â¤Â pH < 3.0).
Related Topics
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Authors
Meng Zhang, Robert Helleur, Yan Zhang,