Obtaining Humic Acids with the Required Structure-Group Composition from Brown Coals
S. I. ZHEREBTSOV, K. S. VOTOLIN, N. V. MALYSHENKO, Z. R. ISMAGILOV
Federal Research Center of Coal and Coal Chemistry, Siberian Branch of the Russian Academy of Sciences, Kemerovo, Russia
Keywords: brown coal, humic acid, modification, biological activity, index of phytoactivity
Pages: 527-532
Abstract
The samples of native and n -butanol-modified humic acids isolated from brown coals of the Kansk-Achinsk and South Ural coal basins (Russia) were obtained. Their composition and properties were characterized using the methods of elemental, spectral, technical analysis and testing for biological activity. Changes in the structural group parameters of modified humic acids were revealed by means of 13C NMR (CPMAS), IR and Raman spectroscopy. The biological activity of native and modified humic acids was evaluated by means of phytotesting with the seeds of Iren wheat. It is shown that modified humic acids are characterized by increased biological activity. This is due to an increase in the relative content of aromatic structural fragments, which is accompanied by an increase in aromaticity index f a and the ratio of aromaticity to aliphaticity f ar/al of humic acids.
DOI: 10.15372/CSD2020261
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