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 copper ion absorption on acrylic acid grafted polypropylene PP-g-AA (ion-exchange) fibers fit this rate equation during the initial absorption process. The moving boundary particle diffusion model fits the entire ion absorption process of chelating fibers converted from the PP-g-AA fibers. Copper ion absorption of ion-exchange fibers is influenced by the total numbers of ions in the liquid and solid phases. Additional ion absorption can occur in fibers containing previously adsorbed ions, but the kinetics of this subsequent absorption process does not fit the moving boundary model.