Sorption of Cr(III) onto chelating b-DAEG-sporopollenin and CEP-sporopollenin resins

In the present study, the removal of Cr(III) from aqueous solution was studied using a new chelate-resins (b-DAEG-sporopollenin and CEP-sporopollenin). Mechanisms including ion exchange, complexation and adsorption to the surface are possible in the sorption process. Adsorption analysis results obtained at various concentrations of Cr(III) showed that the adsorption pattern on the resin followed a Langmuir isotherm. Langmuir constant Gamma(max) and k for Cr(III) were found as 1.23, 84.84 mmol/g for b-DAEG-sporopollenin, 133.33, 10.39 mmol/g for CEP-sporopollenin at 20 +/- 1 degrees C, respectively. In addition, kinetic and thermodynamic parameters such as enthalpy (Delta H-0), free energy (Delta G(0)) and entropy (Delta S-0) were calculated and these values show that adsorption of Cr(III) on b-DAEG-sporopollenin and CEP-sporopollenin was an exothermic process and the process of adsorption was favored at high temperatures. Maximum Cr(III) removal was observed near a pH of 6. (C) 2006 Elsevier Ltd. All rights reserved.