Kara M, Yuzer H, Sabah E, Celik M S
Tubitak-Marmara Research Centre, Materials and Chemical Technologies Research Institute, 41470, Gebze-Kocaeli, Turkey.
Water Res. 2003 Jan;37(1):224-32. doi: 10.1016/s0043-1354(02)00265-8.
Adsorption of Co(II) ions from aqueous sepiolite suspensions has been systematically investigated as a function of several variables including activation conditions, solid to liquid ratio, pH and temperature. The results are analyzed to identify the mechanism of cobalt uptake by sepiolite. Both abstraction and real adsorption isotherms were constructed to isolate the precipitation of cobalt from the real adsorption. Also, for the first time a plausible correlation between the released Mg(II) ions from sepiolite matrix and those adsorbed Co(II) ions is made. A one to one ion exchange mechanism is found to describe the results. The data obtained from adsorption isotherms at different temperatures were fitted to various adsorption models to calculate thermodynamic quantities such as the free energy of adsorption, heat of adsorption and entropy of adsorption. The thermodynamic data indicate that Co(II) adsorption onto sepiolite is entropically driven and characterized by physical adsorption.
作为包括活化条件、固液比、pH值和温度在内的几个变量的函数，对海泡石水悬浮液中Co(II)离子的吸附进行了系统研究。对结果进行分析以确定海泡石吸收钴的机制。构建了提取等温线和实际吸附等温线，以将钴的沉淀与实际吸附分离。此外，首次建立了海泡石基质中释放的Mg(II)离子与吸附的Co(II)离子之间看似合理的相关性。发现一对一的离子交换机制可以描述这些结果。将不同温度下吸附等温线获得的数据拟合到各种吸附模型中，以计算吸附自由能、吸附热和吸附熵等热力学量。热力学数据表明，Co(II)在海泡石上的吸附是由熵驱动的，具有物理吸附的特征。
