Sorption of hexavalent chromium from water and water–organic solvents onto an ion exchanger Tulsion A-23(Gel)

Abstract

The sorption of hexavalent chromium from water and water–organic solvents onto an ion exchange resin Tulsion A-23(Gel) is reported under various experimental conditions such as initial metal concentration, contact time, temperature, pH, and dielectric constant of the medium. The batch ion-exchange process was relatively fast and it reached equilibrium after 110 min of contact. The ion-exchange process, which is pH dependent, showed maximum removal of chromium(VI) in the pH range 7.0–9.0 for an initial chromium(VI) concentration of 0.0011 M. The equilibrium related to Tulsion A-23(Gel) ion-exchange capacity and the total amounts of the ion exchange were obtained using plots of the Langmuir and Freundlich adsorption isotherms. Various thermodynamic parameters have also been evaluated, including differential adsorption enthalpy and entropy.