Adsorption Mechanism of Iodine on Activated Carbon

The characteristics and mechanisms for the adsorption of iodine from aqueous solutions or from organic solvents on activated carbon were studied. Most adsorption terminated in 24 h, but a very slow adsorption was observed even after 2 d for aqueous solutions. It was found that the adsorbed species could be quantitatively predicted using the Freundlich equation, and that Traube's rule holds for the experimental results of the adsorption equilibria from aqueous solutions and from all organic solutions except alcohols. The intraparticle diffusion coefficients of iodine in organic solvents were determined according to the Boyd equation from the experimental adsorption rate results and correlated to the viscosity of organic solvents.