Removal of some chelators from aqueous solutions using polymeric ingredients

Abstract

This work tries to throw a light on the removal of thenoyl trifluoroacetone (TTA) and ethylene diamine tetraacetic acid (EDTA) extractants that extensively used in many nuclear facilities. Using Amberlite XAD resins, equilibrium studies were performed to identify the adsorption of these chelatos from aqueous solutions under various experimental conditions. The applied resins exhibit high retention ability for the studied chelators with a maximum adsorption capacity of 23.9 and 38.0 mg g −1 for sorption of TTA and EDTA on Amberlite XAD4 and 18.6 and 21.2 mg g −1 for their adsorption on Amberlite XAD7. Factors affecting the resin retention ability, such as pH value of aqueous solution and presence of cosolvent have been studied. The kinetics of adsorption behavior, in the applied system, indicate the process to be controlled by more than one diffusion mechanism. Therefore, two diffusion models were utilized to understand and verify the mechanism of adsorption processes; they are the film mass transfer model and the intraparticle diffusion model. The first model, based on film resistance, gave a successful depiction for adsorption of TTA onto Amberlite XAD4 and XAD7. The second one displayed an acceptable prediction for sorption of EDTA onto Amberlite XAD4.