Authors: S.I. Zherebtsov, N.V. Malyshenko, K.M. Shpakodraev, K.S. Votolin

Title of the article: Interaction of copper and lead cations with fractionated humic acids

Year: 2025, Issue: 6, Pages: 50-58

Branch of knowledge: 2.6.12. Chemical technology of fuel and high-energy substances

Index UDK: 662.73

DOI: 10.26730/1999-4125-2025-6-50-58

Abstract: Humic acids (HA) were isolated from brown coals of the Tisul deposit of the Kansk-Achinsk basin (BCTS), its oxidized in-seam form (BCTSO) and the Tyulgan deposit of the South Ural coal basin (BCT). Based on solubility in hydrochloric acid and ethanol, the following humic acid fractions were obtained: hymatomelanic (HmA), humic (HuA) and fulvic acids (FA). The highest yield for all fractions is characteristic of the naturally oxidized in-seam brown coal of the Tisul deposit (BUTSO): HA - 60.9% (of which HmA - 11.3%, HuA - 49.6% and FA - 9.6%) on daf of coal. Elemental analysis, IR and 13C NMR spectroscopy methods showed that the HA fractions are similar in their chemical nature and have similar structural-group and functional composition. All humic acid fractions contain functional groups (carboxyl, carbonyl, hydroxyl) and structural fragments (aliphatic chains and aromatic rings) that characterize the composition and predetermine their properties. They differ in the content of functional groups and the degree of aromaticity. The sorption capacities (E) of HA, FA, HmA and HuA in relation to copper and lead cations were determined. It was shown that E for all fractions for Pb2+ cations exceeds the amount of sorbed Cu2+ cations. Fractions isolated from BUTSO brown coal exhibit higher sorption capacity for both Pb2+ and Cu2+ cations. The data obtained can be used to extract copper and lead cations from various environments

Key words: Brown coal humic acids hymatomelanic acids humic acids fulvic acids IR NMR spectroscopy sorption capacity

Receiving date: 17.04.2025

Approval date: 15.11.2025

Publication date: 22.12.2025

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