engleski

Application of kinetic models in estimation of diffusion coefficients for Zn sorption on clinoptilolite

The ion exchange kinetics of removal of Zn ions from aqueous solutions using natural clinoptilolite has been studied. From the proposed empirical equations the diffusion coefficients have been calculated. Ion exchange of heavy metal ions on natural zeolites is a multistep mass transfer process between the aqueous and the heterogeneous zeolitic phase. The sorption rate could be controlled by several factors including the diffusion of metal ions through the solution and the film surrounding the particle, pore diffusion, and uptake that can involve sorption, ion exchange or complexation. The examination of Zn uptake from solutions over time aims at estimating the parameter of pore diffusion that is considered to be a rate-controlled step.

kinetic models; diffusion; zinc ions; clinoptilolite

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