Ramesh A, Hasegawa H, Sugimoto W, Maki T, Ueda K
Department of Chemistry and Chemical Engineering, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan.
Bioresour Technol. 2008 Jun;99(9):3801-9. doi: 10.1016/j.biortech.2007.07.008. Epub 2007 Aug 14.
The adsorption of Au(III), Pt(IV) and Pd(II) onto glycine modified crosslinked chitosan resin (GMCCR) has been investigated. The parameters studied include the effects of pH, contact time, ionic strength and the initial metal ion concentrations by batch method. The optimal pH for the adsorption of Au(III), Pt(IV) and Pd(II) was found to range from 1.0 to 4.0 and the maximum uptake was obtained at pH 2.0 for Au(III), Pt(IV) and Pd(II). The results obtained from equilibrium adsorption studies are fitted in various adsorption models such as Langmuir and Freundlich and the model parameters have been evaluated. The maximum adsorption capacity of GMCCR for Au(III), Pt(IV) and Pd(II) was found to be 169.98, 122.47 and 120.39mg/g, respectively. The kinetic data was tested using pseudo-first-order and pseudo-second-order kinetic models and an intraparticle diffusion model. The correlation results suggested that the pseudo-second-order model was the best choice among all the kinetic models to describe the adsorption behavior of Au(III), Pt(IV) and Pd(II) onto GMCCR. Various concentrations of HCl, thiourea and thiourea-HCl solutions were used to desorb the adsorbed precious metal ions from GMCCR. It was found that 0.7M thiourea-2M HCl solution provided effectiveness of the desorption of Au(III), Pt(IV) and Pd(II) from GMCCR. The modification of glycine on crosslinked chitosan resin (CCR) was studied by Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM).
研究了金（III）、铂（IV）和钯（II）在甘氨酸改性交联壳聚糖树脂（GMCCR）上的吸附情况。采用分批法研究了pH值、接触时间、离子强度和初始金属离子浓度等参数的影响。发现金（III）、铂（IV）和钯（II）吸附的最佳pH值范围为1.0至4.0，金（III）、铂（IV）和钯（II）在pH 2.0时获得最大吸附量。平衡吸附研究得到的结果用朗缪尔和弗伦德利希等各种吸附模型进行拟合，并评估了模型参数。发现GMCCR对金（III）、铂（IV）和钯（II）的最大吸附容量分别为169.98、122.47和120.39mg/g。使用伪一级和伪二级动力学模型以及颗粒内扩散模型对动力学数据进行了测试。相关结果表明，在所有动力学模型中，伪二级模型是描述金（III）、铂（IV）和钯（II）在GMCCR上吸附行为的最佳选择。使用不同浓度的盐酸、硫脲和硫脲-盐酸溶液从GMCCR上解吸吸附的贵金属离子。发现0.7M硫脲-2M盐酸溶液对从GMCCR上解吸金（III）、铂（IV）和钯（II）有效。通过傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）研究了甘氨酸在交联壳聚糖树脂（CCR）上的改性情况。
