A. V. Savel’eva

Composition of humic acids in peats with various degrees of humification

The structure peculiarities of humic-like substances in plants at a dying stage, humic acids in peat-forming plants humified for two years, and native peats at branches of the Vasyugan bog were determined using spectroscopic techniques. The polydispersity and absorbance of humic acids increased with the degree of humification; the concentration of aromatic and carbonyl-containing carbon in the chemical composition of humic acids increased.

Adsorption properties of modified peat toward organic compounds and heavy metals

The adsorption properties of peat modified by mechanical activation in the presence of iron oxide hydroxide were studied. Based on the results of the determination of adsorption activity and microcalorimetric studies, it was established that physical absorption processes predominate on the interaction of the modified peat sorbents with a model organic substance and the aqueous solutions of metal salts. It was demonstrated that new types of sorbents with high sorption properties can be obtained based on peat mechanically activated in the presence of water treatment wastes

Hydrocarbons in peat-forming plants at eutrophic bogs in Western Siberia

The Western Siberian Plain is a region with the process of swamping paludification occurring on a uniquely large scale. The still poor understanding of the genesis of swamp systems in the Holocene and links between biotic and abiotic processes, on the one hand, and the environment, on the other, call for detailed studying the peat-forming process in various zones [1]. To characterize the environments in which peat is produced in the study area and the conditions under which the organic matter (OM) is further transformed, it is possible to utilize a diversity of parameters of such compounds as normal and isoprenoid alkanes and polycyclic aromatic hydrocarbons. Hydrocarbons in modern sediments are the most stable and geochemically informative fraction. They may be employed as indicators of the fossilization conditions and the original OM type or be utilized to evaluate the degree of the transformations. Lipids in higher plants contain n -alkanes of the homologue series from e 10 to e 40 , with the significant predominance of odd hydrocarbons. The distribution of n -alkanes in sediments is largely controlled by the contribution of the original bioproducers and is represented by compounds from e 13 to e 39 with a decrease in the oddity factor and changes in the proportions of certain hydrocarbon groups [2, 3]. Modern sediments contain no low-molecular aromatic hydrocarbons but were determined to contain a number of polycyclic aromatic (PCA) ones, mostly such holonuclear structures as pyrene, coronene, fluoranthene, perylene, and chrysene. Perylenes and chrysenes are the most widely spread hydrocarbons in humic organic matter [4‐9]. The mechanisms producing them in organic matter is still poorly understood. The genesis of aromatic hydrocarbons is reportedly related to a number of producing factors: the aromatization of steroids and hopanoids in early-diagenetic sediments, anthropogenic contamination, and the reduction of polyaromatic pigments. They can also be generated in the process of biosynthesis and bioassimilation by microorganisms. The main precursors of aromatic structures in the organic matter of modern sediments are thought to be the lignin of peat-forming plants and photosynthesizing organisms [10‐13]. In light of the above facts and considerations, it is interesting to analyze information on the transformations of the composition of hydrocarbons in bioproducers and peats and to estimate them during the biogeochemical transformations of the original OM with regard for the zoning of peat accumulation.

Influence of the conditions of mechanical activation of lignite on the composition and sorption properties of humic acids isolated from it

The results of the study of the influence of mechanical activation of lignite on the composition of isolated humic acids and their adsorption to the quartz river sand were generalized. The changes in the composition of humic acids after adsorption to the sand, which are an evidence of a significant role of phenolic hydroxyls in the process, were demonstrated.

Composition and properties of humic acids from natural and mechanochemically oxidized brown coal

A comparative study of the chemical composition and biostimulation activity of humic acids from natural and mechanochemically oxidized brown coals was performed. It was found that the humic acids obtained from mechanochemically oxidized coal exhibited higher biological activity in comparison with the humic acids from coal oxidized under natural conditions. In this case, they were characterized by a maximum concentration of oxygen-containing groups bound to the aromatic carbon skeleton.

Effect of mechanical activation on the composition of mineral components in humic acids isolated from carbons

It is shown that the mechanical activation of oxidized and brown coals is accompanied by an increase in the yield of humic acids and in their content of functional groups. It was demonstrated by atomic-emission spectroscopy that, under a high-intensity mechanical treatment, mineral elements are redistributed in the coal substance and incorporated into the structure of humic acids.

Comparative study of the fragment composition of humic acids isolated from caustobioliths and soil by the mechanochemical method

Fragment composition of humic acids isolated from solid caustobioliths of varied genesis and from soil was subjected to a comparative analysis. It was found that the composition of these humic acids is affected by the mechanochemical treatment conditions. It was shown that a mechanochemical treatment leads to a decrease in the molecular mass of humic acids to a varied extent for all caustobioliths and to an increase in the content of aromatic fragments in their structure and in the degree of their oxidation.

Sorption Properties of Modified Peat with Respect to Petroleum and Heavy Metals

The group composition of high-moor peat modified by mechanical activation was studied, and the physicochemical characteristics of this peat were determined. It was found that the preliminary mechanical activation of peat, in particular, in the presence of iron oxyhydoxide improved its characteristics as a sorbent for petroleum and heavy metals.

Characterization of the Organic Matter of Humic Acids by Pyrolytic Gas Chromatography–Mass Spectrometry

The results of the pyrolytic analysis of products of the organic matter of Sphagnum fuscum, fuscum peat, and humic acids separated from peat with the use of pyrolysis–chromatography–mass spectrometry in the Rock-Eval version are presented. It was shown that Sphagnum fuscum and peat differed only slightly in the degrees of chemical transformation. Benzene, phenol, and their alkyl-substituted homologues predominated in the thermal desorption products of humic acids upon pyrolysis to 400°C. Acetic acid, monohydric phenols, syringol, and guaiacol, which are the basic compounds in the high-temperature fraction, were formed on the pyrolysis humic acids to 700°C from the carbohydrate, phenylpropionic, and guaiacylpropane structural fragments.

Composition of the water-soluble humic preparations of mechanically activated brown coals

Conditions for the solid-phase mechanochemical activation of coals, which make it possible to substantially increase the yield of water-soluble humic preparations enriched in humic acids and mineral elements, are given in this work. It was found that the humic preparations isolated from mechanically activated coals are characterized by an increase in the antioxidant activity and a change in the cationic and anionic composition. The concentration of acidic ionogenic groups in humic acids increased.