Equilibrium and kinetic studies on removal of Cu super(2+ and Cr) super(3)+ from aqueous solutions using a chelating resin

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2011-08, Vol.172 (1), p.277-286
• Main Authors: Gando-Ferreira, Licinio M, Romao, Ines S, Quina, Margarida J
• Format: Article
• Language: English
• Subjects: Chelating resins; Chromium; Copper; Dynamical systems; Mathematical models; Polymers; Resins
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2011.05.105

In this study, a chelating resin, Diaion CR 11, was studied in order to selectively remove Cu super(2+ and Cr) super(3)+ present in synthetic effluents. Single-component equilibrium isotherm was determined in batch experiments for copper, and an exchange equilibrium based model was used to correlate the experimental data of the binary system Cu super(2+/H) super(+). It was observed that the maximum capacity of the resin increased 2.3 times when the pH varied from 2 to 5 at 25 degree C. The equilibrium constant increased 1.4 times when the temperature changed from 25 to 50 degree C at initial pH of 3. For the operating conditions tested, it was found that the resin exhibited a better selectivity for Cu super(2+ over Cr) super(3)+. A mathematical dynamic model was successfully implemented for describing the saturation behavior of the multicomponent system Cu super(2+/Cr) sub(t)/H super(+ in the column operation. The regeneration of the resin was also experimentally studied by using HCl followed by a mixture of NaOH/H) sub(2)O sub(2. High efficiencies were observed for copper during the first step, where it was almost fully eluted from the resin with 1 M HCl. The use of those regenerant agents in the presence of iron seems to effectively strip chromium from the resin.)