KINETICS OF METAL-ION ABSORPTION ON ION-EXCHANGE AND CHELATING FIBERS

Based on a moving boundary model, a rate equation t = k[X + (1 - X) ln (1 - X)] has been derived for fibrous adsorbents. The kinetics of copp er ion absorption on acrylic acid grafted polypropylene PP-g-AA (ion-e xchange) fibers fit this rate equation during the initial absorption p rocess. The moving boundary particle diffusion model fits the entire i on absorption process of chelating fibers converted from the PP-g-AA f ibers. Copper ion absorption of ion-exchange fibers is influenced by t he total numbers of ions in the liquid and solid phases. Additional io n absorption can occur in fibers containing previously adsorbed ions, but the kinetics of this subsequent absorption process does not fit th e moving boundary model.