Application of Humic Sorbents for Pb{2+}, Cu{2+} and Hg{2+} Ions Preconcentration from Aqueous Solutions

The sorbent prepared by sequential treatment of silica gel by polyhexamethylene guanidine of linear structure and humic acids is suggested for sorption concentration of metal ions (Pb{2+}, Cu{2+} and Hg{2+}) from aqueous solutions. Thermogravimetry and infrared spectroscopy have confirmed the success of the attachment of the humic acids onto modified silica surface. Sorption isotherms of lead (II), copper (II) and mercury (II) obtained in optimal conditions of metals sorption were analyzed by using Freundlich and Langmuir adsorption isotherms. Structural model of surface of humic sorbent was proposed based on the obtained results. The results demonstrated the potential applicability of supramolecular humic sorbent in the preconcentration of metal ions from aqueous solution