Adsorption of Iodine from Aqueous Solutions on to Activated Carbons: Correlation with Nitrogen Adsorption at 77K

Abstract

The adsorption of iodine has been examined on a set of four microporous charcoals subjected to increasing activation, and also on a Vulcan carbon black used as a non-porous reference. Analysis of the iodine adsorption isotherms and of the corresponding differential enthalpies of displacement is consistent with the nitrogen adsorption data, provided that the slightly larger size of the iodine molecule is kept in mind. The α_s method, which is normally applied to adsorption from the gaseous phase, has been usefully extended to these liquid/solid systems and leads to a reasonable micropore volume. This approach provides a useful alternative, especially in those cases where the adsorbent cannot be subjected to drying.