Effect of adsorption of Pb(II) and Cd(II) ions in the presence of EDTA on the characteristics of electrical double layers at the ion exchanger/NaCl electrolyte solution interface

The main propose of this work was to describe the basic parameters of electrical double layer structures of the ion exchanger/NaCl before and after the sorption process of Pb(II) and Cd(II) ions from aqueous solutions in the presence of the complexing agent EDTA (ethylenediaminetetraacetic acid). In the studies the following ion exchangers were used: cation exchangers Micro-ionex (in the H+ and NH4+ forms), Dowex 50Wx4 (in the H+ form), and Dowex 50Wx 12 (in the H+ form): anion exchangers Dowex 1x4 (in the Cl- form) and Dowex 1x8 (in the Cl- form). Study of the physicochemical properties of the sample Surface was carried out. The influence of ionic strength, pH, and solution interface was investigated. Electrophoretic mobility, Surface charge density, and parameters for different concentrations of the electrolytes under question were presented. pH was changed from 3 to 10. The studies were carried out for the M(II)-EDTA = 1:1 system, The effects of the concentration of the solution containing the above-noted complexes and of the ion exchange/solution phase contact time on sorption capacities of the ion exchangers under consideration were studied. Kinetic parameters of the sorption process were also determined. (C) 2009 Elsevier Inc. All rights reserved.