Indian Journal of Chemical Technology, Vol.21, No.1, 56-62, 2014
Kinetic modelling of Fe3+ ion uptake by zeolite from water
The ability of the natural clinoptilolite (Cp), and its Na-enriched form (Na-Cp) to remove iron ions from acid aqueous solutions has been investigated in the batch system at the initial concentration of 100 mg Fe3+/L, pH value of 1.90, and the equilibration time of 30-300 min. In order to establish the Fe3+ uptake behaviour, the rate controlling step of the process and to determine the coefficients, the ion exchange kinetics have been investigated and the different models usually applied are used for description of adsorption kinetics. The Fe3+ uptake by Cp and Na-Cp is evaluated based on the first order kinetics, modified Freundlich and Elovich models, parabolic diffusion and heterogeneous diffusion models. Developed models can successfully describe the ion exchange processes between Fe3+:Cp and Fe3+ :Na-Cp. In addition, the results show that the natural Croatian clinoptilolite enables efficient removal of iron from water.