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 exchange to eliminate heavy metal ions from industrial aqueous liquid streams. The experimental equilibrium data have been satisfactorily correlated using the homogeneous mass action law model (LAM). This model assumes nonideal behavior for both the solution and the solid phase. Wilson and Pitzer equations have been used to calculate activity coefficients in the solid and liquid phases, respectively. The values of the thermodynamic equilibrium constant demonstrate temperature dependence.