Interaction of Copper, Zinc, and Manganese Cations with Lignite and Humic Acids

Abstract

By IR Fourier spectroscopy, EPR, and ¹³C NMR analysis in solids, the sorption of copper, zinc, and manganese cations by various materials from aqueous solutions is studied. The materials considered are Tyul’gansk lignite, Tisul’sk lignite in unoxidized and oxidized forms, humic acids, and the coal residues remaining after separation of the humic acids. The zinc cations are sorbed by ion exchange; copper and manganese cations are sorbed by a mixed mechanism: ion exchange and complex formation. All the samples are selective in terms of sorption of the cations: Cu²⁺ > Zn²⁺ > Mn²⁺.