Competitive adsorption of Li, Na, K, Rb and Cs ions onto calcium alginate-potassium tetraphenylborate composite adsorbent

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	Competitive adsorption of Li, Na, K, Rb and Cs ions onto calcium alginate-potassium tetraphenylborate composite adsorbent
	Guo, Tan 1,2; Hu, Yaoqiang 1,2; Gao, Xiaolei 1,2; Ye, Xiushen1 ; Liu, Haining1 ; Wu, Zhijian1
	2014
发表期刊	RSC ADVANCES
卷号	4 期号:46 页码:24067-24072
摘要	In this study, the calcium alginate-potassium tetraphenylborate (Ca(ALG)(2)-KB(C6H5)(4)) composite adsorbent was synthesized using potassium tetraphenylborate (KB(C6H5)(4)) as the adsorption-active component and calcium alginate (Ca(ALG)(2)) as the matrix material. Different techniques were used for characterization of the adsorbent such as SEM, EDS, XRD, laser particle size analysis and moisture analysis. Competitive adsorption of Li, Na, K, Rb, Cs ions onto the adsorbent was investigated through kinetic curves, adsorption isotherms and column techniques at 25 degrees C. The equilibrium adsorption capacities were compared in the single-element and multi-element systems. The equilibrium adsorption amount was in the sequence Cs+ > Rb+ >> Na+ similar to Li+, and Li and Na ions were hardly adsorbed. The separation factor was found to follow the order beta(Cs/Li) > beta(Rb/Li) > beta(Na/Li) under both the noncompetitive and competitive adsorption conditions. In the kinetic experiments for competitive adsorption, the adsorption reached equilibrium in about 24 h. The equilibrium sorption data were described by the Langmuir and Freundlich isotherm models and the results showed that the Langmuir model with determination coefficients of 0.997 and 0.981 for Cs+ and Rb+ respectively could describe the competitive system at room temperature more correctly. Lower breakthrough ratio and higher adsorption amount were observed for Cs+ in the column experiments for competitive adsorption. Ion-exchange was deduced as the mechanism for selective adsorption of Rb+ and Cs+ ions onto the composite on the basis of EDS and XRD analysis of the adsorbent before and after adsorption. The tetraphenylborate anion (B(C6H5)(4)(-)) had different affinity to different alkali metal ions following the order Cs+ > Rb+ > K+ due to the order of the solubility product K-sp (CsBph(4)) < K-sp (RbBph(4)) < K-sp (KBph(4)).
语种	英语
引用统计
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/5693
专题	青海盐湖研究所知识仓储盐湖资源与化学实验室
作者单位	1.Chinese Acad Sci, Qinghai Inst Salt Lakes, Key Lab Salt Lake Resources & Chem, Xining 810008, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Guo, Tan,Hu, Yaoqiang,Gao, Xiaolei,et al. Competitive adsorption of Li, Na, K, Rb and Cs ions onto calcium alginate-potassium tetraphenylborate composite adsorbent[J]. RSC ADVANCES,2014,4(46):24067-24072.
APA	Guo, Tan,Hu, Yaoqiang,Gao, Xiaolei,Ye, Xiushen,Liu, Haining,&Wu, Zhijian.(2014).Competitive adsorption of Li, Na, K, Rb and Cs ions onto calcium alginate-potassium tetraphenylborate composite adsorbent.RSC ADVANCES,4(46),24067-24072.
MLA	Guo, Tan,et al."Competitive adsorption of Li, Na, K, Rb and Cs ions onto calcium alginate-potassium tetraphenylborate composite adsorbent".RSC ADVANCES 4.46(2014):24067-24072.