Treatment of Simultaneous Ion-Exchange and Adsorption Processes

The situation is more complicated in the case of simultaneous ion-exchange and adsorption processes. In this case, the total sorbed quantity of the Me, cation (a,) is the sum of the quantities sorbed by ion exchange (auJ and adsorption 

For the evaluation of the isotherm, Equation 1.119 should be used. Since there are several parameters (up to 7), the experimental separation of ion exchange and adsorption can be simpler (Chapter 2, Section 2.6). 

On the basis of those discussed here, we can say that the thermodynamic parameters of ion exchange determined by linear isotherm equations are not correct. We determine the mechanism of sorption (ion exchange and/or adsorption) and then choose the isotherm equation. When simultaneous interfacial processes take place, the dominant process, if any, has to be selected or experimentally separated, or Equation 1.119 should be used. 

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