Column Dynamics of Ternary Ion Exchange Part I: Diffusional and Mass Transfer Relations

Abstract

The complete multicomponent ion-exchange diffusion equations based on irreversible thermodynamics and their approximations by the Nernst-Planck model or the Fick's law model are all put in the same algebraic form. Their differences occur only in the definition of the diffusion coefficients. Multicomponent diffusion coefficients. Multicomponent diffusion coefficients are related to those in binary systems by either the Nernst-Planck or Fick's law model. Using a linear driving force approximation for the flux equations, similar relationships are developed for estimating multicomponent (ternary) mass transfer coefficients based on the analysis of binary data. Hence from binary data and these relationships, multicomponent effluent concentration histories may be predicted numerically.