Adsorption Equilibria of Single-Component and Multi-Component Metal Ions on to Scrap Rubber

Abstract

The ability of scrap rubber to adsorb the three metal ions, copper, cadmium and zinc, in single-component and multi-component mixtures in aqueous solutions has been studied. A comparison has been made between the single-component saturation uptake and the multi-component uptakes. The experimental results were fitted to the Langmuir, Freundlich and Redlich–Peterson isotherms. The correlation coefficients obtained from plotting these isotherms gave a measure of the conformity of the data to a linear trend and corresponded to a perfect fit. The isotherms indicated a competitive uptake, with copper being preferentially adsorbed by scrap rubber in multi-component solutions. The capacity of scrap rubber for the single-component metals was in the order: Cd > Cu > Zn. On the other hand, the order of preference of scrap rubber for metals in multi-component mixtures was: Cu > Cd > Zn.