Sorption of Rare Earth Elements by Organic Matter from Aqueous Solutions according to Experimental Data

It is shown by laboratory experiments that peat, brown coal and its organomineral components, and microscopic fungi extracted from brown coals exhibit a high potential for extraction of all rare earth elements (REEs) from aqueous solutions. Physical sorption, ion-exchange reactions with the involvement of carboxyl and hydroxyl groups, and complexation with ‒ОН, ‒СО, and ‒СООН groups are included in the REE sorption processes by OM components. The REE-bearing mineral phases, which form due to interaction with N- and P-bearing functional protein groups of a cellular envelope are revealed by SEM-EDS study of the fungi biomass. The involvement of a biotic component in the formation of REE mineralization in brown coal sediments is indicated.