Interaction of humic compounds with constant and variable valence metals in acidic solutions

Abstract

The mechanism of the interaction of the humic substances (HSs) of peat and brown coal with the ions of constant (Zn and Pb) and variable valence (Cu, Cr, Co, and Ni) metals in acidic solutions (pH 2) was studied. It was established that the constant valence metals weakly interacted with HSs by an ion-exchange mechanism. However, the variable valence metal ions in an aqueous medium also interacted with the polyconjugation systems of HSs to create prerequisites for developing sorbents based on the HSs of caustobioliths for variable valence metals in acidic solutions.