Ion exchange accompanied by neutralization reaction: Removal of dilute acids by anion exchange

Abstract

The kinetics of exchange between an anion resin in the OH- form with dilute acids was studied in a batch system. The resin used was Dowex 1-X8 and the acids prepared for the experimental work were 0.005 to 0.01 N HCl and H2SO4. The results of study showed that a film diffusion model with a constant rate parameter fits all experimental data very well. The experimental results also showed that the rate is inversely proportional to the resin radius as predicted by the film diffusion model. It was found that the rate for Cl-OH- exchange is higher than that for the SO42--OH- exchange. This higher rate of exchange is attributed to the higher effective diffusivity for the HCl-OH- system as compared to that for the H2SO4-OH- system.