SORPTION STUDIES ON ION-EXCHANGE RESINS .1. SORPTION OF STRONG ACIDS ON WEAK BASE RESINS

Sorption equilibria and batch dynamics of strong acids (HCl and HNO3) On weak base ion exchange resins, in free base form, are studied. The sorption process shows significant reversibility even at high concentrations of acids. It is also concluded from the dynamic studies that the extent of exclusion of hydrogen ions from the resin pores is far less than that predicted on the basis of complete dissociation of counterions from the protonated ionogens. An attempt is made to correlate the sorption equilibria and sorption dynamics by considering an electric double layer at the pore walls. A reversible sorption model, which accounts for sorption equilibrium at ionogenic sites of resin, fits the experimental dynamics satisfactorily over the entire range of the resin conversion. Values of the effective pore diffusion coefficient of the acids, regressed from the observed dynamics, have been satisfactorily correlated on the basis of the developed theory.