Kinetic and thermodynamic sorption studies of Fe(iii) and Zr(iv) by DFO@Purolite, a desferrioxamine B based chelating resin

This paper presents the characterization of a novel solid-phase sorbent for iron(iii) and zirconium(iv) obtained by the functionalization of a commercial epoxy methacrylate resin (Purolite & REG; ECR8209) with desferrioxamine B (DFO). The sorption properties of the solid material, named DFO@Purolite, towards Fe(iii) and Zr(iv) were investigated in detail. In particular, the sorption kinetics, isotherms and sorption profiles as a function of the solution's pH were studied. The stoichiometry and the complexation constants of both cations with the active sites of the sorbent were determined by applying the Gibbs-Donnan model, i.e., the model used to explain the protonation and the metal sorption on ion exchange resins. While the chelating properties of the solid material investigated herein are in good agreement with those of Fe(iii)/DFO and Zr(iv)/DFO previously determined in homogeneous aqueous solutions, the solid/liquid extraction studies further allow to ascertain the speciation model for the latter system that is still subjected to controversy in the literature.