An experimental investigation of heavy metal adsorption by a commercial chelating ion exchange resin

A series of binary equilibrium experiments were conducted in order to provide sufficient data for the determination of the equilibrium constants and binary interaction parameters for the systems Cd⁺⁺/Cu⁺⁺, Na⁺/Cd⁺⁺ and Na⁺/Cu⁺⁺ on a commercial, chelating ion exchange resin, SR-5, marketed by Sybron Chemicals Inc. The Pitzer equation was used to determine the liquid phase activity coefficients, while the procedure proposed by Smith and Woodburn along with the Wilson model was used to determine the equilibrium constants Kab and the binary interaction parameters A_AB and A_BA The binary parameters were then used to predict the behavior of the three component system Na⁺, Cd⁺⁺ and Cu⁺⁺ on the same resin, using the mass action equilibrium model and to evaluate the average separation factors for these systems. These separation factors were then used to estimate the breakthrough time for each of the three cations from a fixed bed of resin by the simple, multicomponent, equilibrium, non-dispersion model of Helfferich.