'Association for Promotion of Holistic Approach to Environment'
Abstract
The effect of particle size and initial lead concentration on the kinetics of lead ions uptake onto natural zeolite has been examined by batch experiments. The uptake rate of lead ions increases with decreasing particle size and has no effect on the zeolite removal capacities. Also the removal capacities are not affected by initial lead concentrations. To identify the rate rate-determining step, experimental data have been tested by the Lagergren pseudo-first order, Ho pseudo-second order and Elovich reaction kinetic models, Vermeulen’s, Parabolic and Homogeneous diffusion models. For different lead concentrations and particle sizes the kinetic constants obtained have been changed and have consequently been excluded as relevant for the description of kinetics. Vermeulen´s and Homogeneous diffusion models have shown the best fitting with the experimental data, what confirms that intraparticle diffusion is rate-determining step of uptake process of lead ions onto natural zeolite
