Sorption of Impurity Elements by the Components of Lower–Middle Miocene Lignite from the Sergeevskoe Deposit (Upper Amur Region)

Based on model experiments on the sorption of chemical elements from multicomponent solutions with fungi biomass, lignite, and humic acids, it was assumed that qualitative changes in organic matter during the transformation of plant biomass into coal controlled the predomination of one of the sorption mechanisms. At the initial stage, the biomass of microscopic fungi may contribute to fixation of significant volumes of elements with the formation of zero-valent particles due to a combination of the mechanisms of ion exchange, chelation, and reduction reactions. Subsequently, mostly due to ion exchange, humic acids may fix significant volumes of Cu, Cr, Zn, Co, Ni, Pb, and Fe with the formation of organomineral compounds. Many fewer elements are sorbed on lignite, and this proceeds mainly by the mechanism of intermolecular interactions.