The objective of this work is to study the mineral composition of bottom sediments of eight small lakes located on the right bank of the Ob River (Western Siberia) in the Surgut region of the Khanty-Mansiysk Autonomous Okrug - Yugra. The studies were carried out using wave dispersive X-ray fluorescence (WDFR) spectroscopy. The content of organic substances, ash, and oxides in the ash in the samples was determined. Based on these data, the studied bottom sediments were classified. The bottom sediments of Lake S-1 are siltstone sands, lakes Vach Lor and S-189 - weakly sapropelic siltstone sands, lakes S-5, S-6, S-3, S-89, and S-294 - typical sapropels. The article presents the content of the main elements in the ash of the studied samples.
The paper presents the results of a study of the paramagnetic activity of humic and hymatomelanic acids extracted from sapropels of ten small lakes on the right bank of the Ob River and ten small lakes on the left bank of the Ob River (Western Siberia). Quantitative studies were carried out by two methods: the ABS spins method and the method using a double resonator with respect to TEMPO. A comparison of the two methods is presented. The values of the concentration of paramagnetic cents per gram of humic and hymatomelanic acids, as well as the molecular weights of the conditional paramagnetic molecules of humic and hymatomelanic acids were calculated. Based on the results obtained, a conclusion was made about the greater paramagnetic activity of humic acids relative to hymatomelanic acids. Differences in the paramagnetic activity of humic acids and hymatomelanic acids have been established. Three samples from lakes on the right bank of the Ob River and one sample from a lake on the left bank of the Ob River have the greatest differences in paramagnetic activity between HAs and their corresponding HMCs. The concentration of paramagnetic centers in the HAs of these samples is six times higher than in the corresponding MMCs. The contribution of the conjugated aromatic component to the structure of the macromolecules of these HAs is the greatest.
Abstract. The article analyzes the effect of thermal modification of different-type peat on the alteration of elemental and functional composition of peat humic acids. Based on the data of IR-spectra and readings of electron paramagnetic resonance, structural alterations are identified. It is shown that the impact of peat characteristics on humic acids is preserved after thermal modification. It is revealed that the strongest alteration of humic acid composition and properties caused by peat heating are typical to humic acid samples extracted from the peat with low decomposition degree.
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