Ion-exchange equilibria of Cu2+, Cd2+, Zn2+, and Na+ ions on the cationic exchanger amberlite IR-120

Equilibrium ion-exchange isotherms of Na+/Cu2+, Na+/Cd2+, and Na+/Zn2+ on a strong acid resin, Amberlite IR-120, in aqueous medium at (283 and 303) K have been determined in order to assess the possibility of using ion exchan ge to eliminate heavy metal ions from industrial aqueous liquid streams. Th e experimental equilibrium data have been satisfactorily correlated using t he homogeneous mass action law model (LAM). This model assumes nonideal beh avior for both the solution and the solid phase. Wilson and Pitzer equation s have been used to calculate activity coefficients in the solid and liquid phases, respectively. The values of the thermodynamic equilibrium constant demonstrate temperature dependence.