Adsorptive removal of Cu(II) and Ni(II) ions from aqueous media by chemical immobilization of three different aldehydes Original Research Article

The three aldehydes were chemically immobilized onto silica gel modified with 3-aminopropyltrimethoxy silane, just as the classic condensation reaction of Schiff bases. The obtained silica gel structures used as adsorbent were characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The adsorption capabilities of these adsorbents towards Cu(II) and Ni(II) from aqueous solutions were studied and values of adsorption were detected by an atomic absorption spectrometer. The maximum adsorption capacities and isotherm parameters were found from the Langmuir and Freundlich equations. The characteristics of Ni(II) and Cu(II) metal bindings were interpreted by using Scatchard plot graphics, and it was showed that in different concentrations multi-type and/or nonspecific interactions among metal ions and modified silica gel structures were the prevailing effects causing the Ni(II) and Cu(II) adsorptions. Conclusively, probable benefit of each specific binding type in adsorptions of Ni(II) and Cu(II) from aqueous media has been discussed in detail.