ISSN:0736-6299    

DOI:10.1080/07366299908934620

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Li-NMR chemical shifts were studied on adsorbed lithium ions in strongly acidic cation exchange resins with different degrees of crosslinking. The observed chemical shifts measured from the reference peak of butyl lithium have shown a linear relation with crosslinking degrees, regardless the types of gel or porous resins. Li-NMR chemical shifts, relating to the chemical conditions of the adsorbed lithium ion, directly indicate the microscopic environment of the ion exchange sites where cations are accommodated. Thus Li-NMR can be used as a convenient tool to analyze the crosslinking degrees or mobility of cations in the cation exchange resins.

ISSN:0736-6299    

DOI:10.1080/07366299908934621

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Experiments of binary and ternary ion exchange equilibrium of heavy metals and sodium were carried out in a complexing iminodiacetic resin Lewatit TP 207. First, binary equilibrium data were obtained at different temperatures and ionic strength and fixed to models considering two different ion exchange stoichiometrics. For ternary equilibrium data, two distinct simple models were applied. One to be applied to systems showing very different selectivity for the metals (for instance, Cu2+/Co2+/Na+) and the other for systems with similar selectivity for the metals (such as Zn2+/Co2+/Na+). The ternary equilibrium data obtained is presented in this work and fitted using the two above mentioned models. These models allow us to obtain the equilibrium parameters for binary and ternary system to be used in the design of equipment using this iminodiacetic resin.

ISSN:0736-6299    

DOI:10.1080/07366299908934622

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor