New approach to Cu(Ⅱ), Zn(Ⅱ) and Ni(Ⅱ) ions removal at high NaCl concentration on the modified chelating resin

摘要

In this study the commercially available chelating ion exchanger Lewatit TP 260 modified for the effective sorption was used for removal of Cu(II), Zn(II) and Ni(II) ions from aqueous acidic solutions. During the modification the resin was converted into Na+ or 2Na(+) form. It was found that different conditions such as pH, concentration and form of the functional groups affect the sorption efficiency of the aminophosphonate resin towards the above-mentioned heavy metal ions in aqueous solutions at a low pH value. The maximum sorption capacity of Lewatit TP 260 towards Cu(II), Zn(II) and Ni(II) was obtained for the 2Na(+) form. The sorption kinetic data were found to fit the pseudo-second-order model as compared with the pseudo-first-order model. The intraparticle diffusion model suggested that the sorption process was dominated by the external mass transfer of Cu(II), Zn(II) and Ni(II) ions to the surface of Lewatit TP 260 with the aminophosphonate functional groups in the 2Na(+) form.