Mathematic modeling of exchange kinetics for NH4+ adsorption on K saturated clinoptilolite

ABSTRACT

Homoionic k-clinoptilolite was evaluated as a reservoir for NH4+ and a source of nutrients such as K+. Kinetic studies of the NH4 adsorption and consequently K-release on K-clinoptilolite were performed aiming to throw more light on the mechanism of NH4+ adsorption-desorption process in aqueous media. Several models [zero-, first-, second-order, parabolic diffusion, Elovich and power function equations] were applied to the kinetic data to select the most suitable model for the description of the ammonium exchange process on the surface of zeolite minerals