Removal of some hazardous heavy metals from aqueous solution using magnetic chelating resin with iminodiacetate functionality

A magnetic chelating resin with iminodiacetate functionality was prepared and investigated. This resin showed a powerful uptake behavior towards Pb(II), Cd(II), Zn(II), Ca(II) and Mg(II). Kinetic and thermodynamic characteristics of uptake process were evaluated. The uptake values obtained are comparable to that of commercial resin with the same functionality (Lewatit TP-207) but with faster kinetics. A correlation was found between the affinity of the resin towards the investigated metal ions and the values of stability constants of their complex formation. The regeneration of the resin was carried out using 0.2 M EDTA with efficiency over 96%. Recovery of Pb(II) (as an example) from aqueous solutions using column technique was carried out. The total adsorption capacity (N-o) value obtained from bed depth service time (BDST) model was found to be comparable with the experimental value of q(s). The values of critical bed height (Z(o)) and rate constant of adsorption (K-a) were found to be 0.583 cm and 41.9 L/(mol min). (C) 2007 Published by Elsevier B.V.