SORPTION STUDIES ON ION-EXCHANGE RESINS .2. SORPTION OF WEAK ACIDS ON WEAK BASE RESINS

Sorption equilibria and batch dynamics of weak acids (formic acid and monochloroacetic acid) on weak base ion exchange resins, in free base form, are studied. The reversible sorption model based on double layer theory, developed in part 1 of these studies, is extended to take into account undissociated acid species. The model fits the experimental dynamics satisfactorily over the entire range of resin conversion. Values of effective ionic pore diffusion coefficient, regressed from the observed experimental dynamics, have been satisfactorily correlated on the basis of the model. These studies reveal that the contributions of both the ionic and the undissociated molecular species are important in determining the total diffusive flux of the acid in the pores of the resin.