Prediction of Multicomponent Ion-Exchange Equilibria for a Ternary System from Data of Binary Systems

Abstract

A framework is developed to provide predictions of multicomponent ion-exchange equilibria from binary data. Our input data were taken from published experimental results on the ion-exchange equilibria of the binary systems Sr2+–Na+, Cs+–Na+, and Sr2+–Cs+ on chabazite zeolite. These systems exhibit nonideal characteristics in both solid and liquid phases. The experimental characterization has been based on the reaction equilibrium constants and the activity coefficients in both phases. The activity coefficients of the exchanger phase were obtained from the well-known Wilson model. A computer program was given in FORTRAN-77 to carry out the prediction procedure. The sum of the squares of differences between experimental and predicted points was used as a criterion for best fit. The model was also verified on systems involving the exchange of the anions SO− 4, NO− 3, and Cl− on Amberlite IR-400. The good agreement between the experimental and predicted data showed that the proposed framework can be considered as an effective method to predict many ternary systems from binary systems.