APPLICATION OF THE ELOVICH EQUATION TO THE KINETICS OF METAL SORPTIONWITH SOLVENT-IMPREGNATED RESINS

The sorption rates of metal ions including Fe(III), Co(II), Ni(I I), C u(II), and Zn(II) from sulfate solutions with macroporous resins conta ining bis(2-ethylhexyl)phosphoric acid (D2EHPA) were measured and comp ared in a batch stirred vessel. Experiments were carried out as a func tion of the pH and metal concentration in the aqueous phase, D2EHPA co ncentration in the resin phase, and temperature. The effect of impregn ation methods of D2EHPA on the sorption rate was also investigated. It was shown that all sorption processes could be well described by the Elovich equation. For the examined systems there were similar trends o f sorption rates with respect to the concentrations of metal ions and D2EHPA. With respect to the pH, however, three different trends were o btained depending on the magnitude of sorption rate. The apparent acti vation energy was obtained and used to discuss the rate-controlling me chanism.