化工进展2017，Vol.36Issue(2)：712-719,8.DOI:10.16085/j.issn.1000-6613.2017.02.043
壳聚糖凝胶球对Cu（Ⅱ）和Cr（Ⅵ）吸附行为的对比
Comparison for Cu(Ⅱ) and Cr(Ⅵ) adsorption behavior onto chitosan hydrogel beads
摘要
Abstract
To facilitate the separation of chitosan powder after adsorption process,we adopted the sol-gel and freeze-drying method for the synthesis of millimeter-scale chitosan hydrogel beads(2.8 to 3mm),and further revealed the different adsorption behavior for Cu(Ⅱ) and Cr(Ⅵ) ions. Results showed that the optimum pH value for the adsorption of Cr(Ⅵ) and Cu(Ⅱ) ions was 3.0 and 5.5, respectively;The adsorption equilibrium achieved in 2h for Cr(Ⅵ) and 25h for Cu(Ⅱ) ions;The adsorption process for Cu(Ⅱ) ions was spontaneous and endothermic reactions with the increase of entropy. In a contrary,the adsorption process for Cr(Ⅵ) ions was spontaneous and exothermic reactions with the decrease of entropy;Desorption efficiency for Cu(II)-loaded CHBs(Cu-CHBs) was relatively low,while the desorption of Cr(Ⅵ)-loaded CHBs(Cr-CHBs) was conducted easily. Additionally,based on the results of FTIR and five models,including Langmuir isotherm,Freundlich isotherm,pseudo-first order kinetics,pseudo-second order kinetics,and intra-particle diffusion model.the adsorption process onto CHBs was monolayer chemisorptions for Cu(Ⅱ) ions and adsorption-reduction process for Cr(Ⅵ) ions mainly including monolayer chemisorptions together with multilayer physisorptions. The maximal adsorption capacities for Cu(Ⅱ) ions and Cr(Ⅵ) ions were 155.67mg/g and 185.08mg/g,respectively. This indicates that freeze-drying medthod enhanced adsorption capacity of CHBs are promising to solve the separation of chitosan powders.关键词
壳聚糖凝胶球/冷冻干燥/Cu(Ⅱ)和Cr(Ⅵ)/吸附/还原/动力学模型Key words
chitosan hydrogel beads(CHBs)/freeze-drying/Cu(Ⅱ) and Cr(Ⅵ) ions/adsorption/reduction/kinetic modeling分类
资源环境引用本文复制引用
张艺钟,刘珊,刘志文,吴文成,邓东阳,鞠勇明..壳聚糖凝胶球对Cu（Ⅱ）和Cr（Ⅵ）吸附行为的对比[J].化工进展,2017,36(2):712-719,8.基金项目
广东省科技计划（2016A020221017）及环境保护部百人工程项目。 （）
