Polyacrylate anion exchangers in sorption of heavy metal ions with the biodegradable complexing agent

The removal of Co(II) and Ni(II) from aqueous solutions in the presence of complexing agent on the polyacrylate anion exchangers with different basicity of functional groups Amberlite IRA 458, Amberlite IRA 958 and Amberlite IRA 67 was described. The complexing agent Baypure CX 100 is a new generation of chelators, undergoing biodegradation. It constitutes an alternative for the reagents of EDTA or NTA type. The studies were carried out by the static (batch) and the dynamic (column) methods. The influence of several parameters such as ratio of M(II)-L, pH, temperature were studied with respect to sorption equilibrium. Sorption isotherms were obtained and fitted using the Langmuir and Freundlich models. Kinetic curves were fitted using the pseudo first-order, the pseudo second-order as well as the intraparticle diffusion model equations to evaluate most effective one. Physicochemical properties of anion exchangers such as their structure, basicity of functional groups were also taken into account. Additionally, the obtained results were compared with those for the weakly acidic cation exchanger Purolite C-104. (C) 2009 Elsevier B.V. All rights reserved.