Extraction of Iron and Manganese Ions from Aqueous Systems by Carbon-Based Absorbents

The mutual influence of heavy metal ions when they are adsorbed by SKD-515 granulated carbon is investigated; attention centers on ions typical of mine and quarry runoff at mining enterprises. The change in sorbent texture after absorption of pollutant ions is assessed by various physical and chemical methods. In studying the equilibrium and kinetics of heavy metal absorption by SKD-515 granulated carbon, it is found that the presence of a second ion markedly decreases the equilibrium adsorption of Fe²⁺ ions; for Mg²⁺ ions, the second ion reduces the rate at which equilibrium is attained. The Langmuir and Dubinin–Radushkevich models are used to calculate the basic parameters of adsorption equilibrium. The kinetic model describing adsorption is determined, and the contribution of diffusion in the film during the limiting stage of extraction is estimated.