a new film diffusion controlling kinetic model for adsorption at the solid/solution interface

A convenient adsorption kinetic equation has been offered for the modeling of adsorption kinetics in batch systems when diffusion taking parts to the rate-controlling step of adsorption. this model is suggested based on the smoluchowski-waite equation for diffusion-controlled second-order reactions. the proposed new model has better performance (lower absolute values of the relative errors (aare) %) respect to the pseudo-second-order. results of this equation are in agreement with experiment data especially at the initial times of adsorption that diffusion contributes to the rate-controlling step of adsorption.