Sorption of nicotinic and isonicotinic acids by the strongly basic anion exchanger AB-17-8

Thermodynamics and kinetics of sorption with the participation of nicotinic and isonico-tinic acids on the strongly basic anion exchanger AB-17-8 were studied. According to calori-metric measurements, partial (differential) heat of sorption was estimated for anions and zwitterions of pyridinecarboxylic acids upon sorption by the OH-form of the anion exchanger AB-17-8 at 298K. Sorption of zwitterions of pyridinecarboxylic acids by the OH-form of the strongly basic anion exchanger can be presented as the process that involves independent reactions of ion exchange, dissociation of pyridinecarboxylic acid, and neutralization. The kinetics of sorption on the strongly basic anion exchanger with the participation of nicotinic and isonicotinic acids is shown to be controlled by the slow diffusion of the components in the polymer phase. For the organic anion in the phase of the anion exchanger AB-17-8, the diffusion coefficient is equal to (1.3 +/- 0.4). 10(-12) m(2) s(-1).