Home – Home – Jornals – Chemistry for Sustainable Development 2026 number 4

The effect of low molecular weight polyethylene glycols (PEG) and nonionic surfactants on the compatibility, number of viable cells, and antifungal activity of Bacillus velezensis strains BZR 336g and BZR 517 was investigated. The studies were conducted on the phytopathogen Fusarium graminearum as the test culture. Most of the adjuvants studied do not have an inhibitory effect on the strains and can be used in biological preparations. However, certain substances (PEG-200, Tween-60, Glycereth-26, Glycereth-12) reduced antifungal activity, especially in the later stages of incubation. The BZR 517 strain demonstrated higher and more stable antifungal activity compared to BZR 336g. The most optimal adjuvants for strain BZR 336g were determined to be PEG-300, PEG-400, and Laureth-2, while PEG-200, PEG-400, Tween-80, and Tween-60 were found to be the most optimal ones for strain BZR 517, which allows these substances to be considered as promising adhesives for microbial fungicides.

Using a complex of physical and physicochemical methods (spectroscopy in the visible region, IR, NMR, EPR spectrometry, X-ray diffraction, elemental analysis, Rock-Eval pyrolysis), some features of the composition and structure of asphaltenes in oils and dispersed organic matter in the rocks of Western Siberia were studied. The composition and properties of asphaltenes reflect changes in the oil genetic types, similar to those previously established during the study of the hydrocarbon part: from marine oils of the Latitudinal Ob region to continental oils of the northern regions. The geochemical patterns of changes in the composition and structure of asphaltenes of dispersed organic matter were discovered. Passing from the Volga stage of aquagenic origin up and down the section of Western Siberia, the signs of terrigenous type of organic matter appear in asphaltene structure: the atomic ratio of hydrogen to carbon decreases, the contribution from condensed aromatic fragments increases, and metal-porphyrin complexes are not detected.

La_0.4Sr_0.6Fe_0.95Mo_0.05O_3-δ  microtubular membranes were prepared by the phase inversion method followed by sintering. Porous catalytic layers consisting of 1) 30%LaFe_0.7Ni_0.3O_3-δ/(30%Ce_0.9Gd_0.1O_2-δ-40%NiO), 2) LaFe_0.4Ni_0.6O_3-δ  were applied onto their inner surface. Preliminarily synthesised components of the membrane catalytic layers were studied by X-ray diffraction, revealing a monophasic composition of the studied complex oxides, without any impurities. The absence of chemical interaction between the membrane material La_0.4Sr_0.6Fe_0.95Mo_0.05O_3-δ  oxide and catalytic layers was established. According to the data of scanning electron microscopy, microtubular membranes, obtained by phase inversion followed by sintering, possess complex microstructure characterised by the presence of a gas-tight layer about 200 μm thick, surrounded by porous catalytic layers 10 m thick, with the uniform distribution of elements over the surface. It was demonstrated that the obtained microtubular membranes with deposited porous layers effectively activate methane when atmospheric oxygen and carbon dioxide are used as oxygen sources on the feed side of the membrane.

The influence of ethylene propylene diene rubbers SKEPT-40, S 501A, S 505A and S 537-2, as well as softeners (industrial oil I-8A, naphthenic oils NMR-12 and NKM-40, dibutyl phthalate) on the rheometric parameters of the rubber compound, physico-mechanical and performance properties of vulcanised rubber with a sulphur vulcanisation system has been investigated. The rubber compound included ethylene propylene diene rubber, vulcanising agent (sulphur), vulcanisation accelerators (2-mercaptobenzthiazole and tetramethylthiuram disulfide), vulcanisation activators (zinc white and stearic acid), filler (technical carbon P 324), softener (one of the above oils and dibutyl phthalate). The work was carried out in two stages: at the first stage, the influence of the ethylene propylene diene rubber brand was studied, and at the second stage, the influence of softeners on the rheometric properties of the rubber compound, physico-mechanical and performance characteristics of vulcanisates. It has been shown that vulcanised rubber based on ethylene propylene diene rubber S 505A, containing 15.0 parts per hundred rubber (phr) of industrial oil I-8A as a softener, possesses improved physico-mechanical and performance characteristics and can be recommended for the manufacture of anti-corrosion protective coatings for metal products exposed to acid-base environments.

When formulating liquid fertilisers, a key challenge is identifying the highest possible concentration of components in the solution, as this affects storage and transportation conditions, usage guidelines, and pricing. A method for optimisation of the compositions of liquid potassium fertilisers using phase diagrams of polycomponent water-salt systems formed by KNO₃, KH₂PO₄, KCl and K₂SO₄ has been proposed and implemented. Optimisation criterion was chosen to be solution concentration and the specific combination of salts that enable the production of the most concentrated fertiliser with a specific N : P₂O₅ : K₂O ratio. The diagrams facilitate the determination of the liquid fertiliser composition to fall within the homogeneous region, thereby ensuring its stability throughout the shelf life. Experimental findings regarding the solubility of salts in the systems KNO₃-KH₂PO₄-KСl-H₂O, KNO₃-KH₂PO₄-K₂SO₄-H₂O, KCl-KH₂PO₄-K₂SO₄-H₂O, KСl-K₂SO₄-KNO₃-H₂O and KCl-KH₂PO₄-KNO₃-K₂SO₄-H₂O at 25 °C are presented. The composition of saturated solutions for various combinations of salts was determined. Analysis of the acquired data indicates that the maximum saturation level (37.1 wt% of salts) corresponds to the solution that is saturated with nitrate, dihydrogen phosphate, and potassium chloride. A methodology for calculating the composition of a saturated solution with a given ratio of N : P₂O₅ : K₂O is proposed and theoretically validated.

This review presents current development trends in the field of composite materials based on ceramic matrices modified with carbon nanotubes (CNTs). The main approaches to their production and the mechanisms by which CNTs affect the structure and properties of ceramics are discussed, including the formation of electrical conductivity percolation pathways, increased mechanical strength, enhanced crack resistance, modification of the interphase boundary, and improved functional characteristics. Ceramic composite materials are divided into two main groups depending on their formation conditions: low-temperature and high-temperature. The first group includes composites produced at temperatures from room temperature to 250 °C, at which CNTs retain their structure and functional groups. Examples include the production of SiO₂-CNT aerogels and cement composites. The second group includes composites that have undergone high-temperature processing up to 2000 °C during their production. This group included composites in which carbon nanotubes retained their core (Al₂O₃-MWCNT conductive ceramics, hydroxyapatite-based bioceramics), as well as composites in which carbon nanotubes, introduced into the interparticle space of the ceramic matrix, acted as sacrificial additives to form strong interphase boundaries in reaction-bonded carbides. It has been shown that the introduction of carbon nanotubes enables the formation of new interphase boundaries and hierarchical structures that determine the mechanical, electrical, optical, and radar-absorbing properties of the composites. Potential applications of such materials in biomedicine, optical systems, radar-absorbing coatings, electronics, and structural components are described.

Desulphurisation remains a critical focus of petroleum processing research, as sulphur-containing compounds are present in the majority of crude oils, degrade the quality of petroleum products and have a detrimental impact on the environment. The effect of oil-soluble catalyst precursors based on the tallates of iron, nickel, cobalt and chromium in a petroleum-based solvent (nefras-С4-155/205, white spirit) with the addition of a suspension of alkaline metal on the transformation of sulphur-containing compounds during simulation of desulphurisation processes was assessed. Thiophene and diphenyl sulphide were used as model systems, subjected to high-temperature aquathermolysis at 150 and 250 °C, in the presence of a commercial form of oil-soluble catalyst precursors based on tallates of iron, nickel, cobalt and chromium in the solvent (nefras) with and without the addition of sodium suspension in vaseline oil. The reaction products were analysed using gas chromatography and mass spectrometry, the concentrations of sulphide and mercaptan sulphur in aqueous products were determined via titration in accordance with GOST R 56871-2016, the phase composition of the catalysts and resulting solid products was examined using X-ray diffraction analysis. The results demonstrate that the model systems are transformed under the action of reagents. The interaction of thiophene with sodium leads to the formation of butene-2, butanone-2, methylheptadienes, dimethylheptane, octadienes, and dodecadienes. The reaction of sodium with diphenyl sulphide yields benzene and thiobenzene. The X-ray diffraction analysis of the post-reaction catalysts after autoclave experiments with thiophene and diphenyl sulphide revealed the formation of metal sulphides, sulphates, and oxides, thus confirming the occurrence of desulphurisation. The findings can be put to practical use in further studies of desulphurisation processes in crude oil and petroleum products.

The effect of acylation of petroleum tar with trifluoroacetic anhydride on its chemical composition and colloidal stability has been studied. Tar contains a large amount of polycyclic aromatic hydrocarbons (including resins and asphaltenes) capable of acylation by the Friedel-Crafts reaction. The introduction of oxygen- and fluorine-containing functional groups increases the polarity of molecules and changes the colloidal stability of petroleum disperse systems. In the course of work, the duration of acylation process (1, 4 or 8 h) and the concentration of trifluoroacetic anhydride (5, 15 or 25 wt%) were varied both in the presence of a catalyst (anhydrous aluminium chloride) and without it. Analysis of the composition, structure, and colloidal stability of tar and acylation products was carried out using NMR ¹H spectroscopy, IR spectroscopy, liquid adsorption chromatography, and spectrophotometry. It has been shown that acylation without the catalyst leads to insignificant changes in the composition. The use of the catalyst promotes more pronounced chemical transformations, increasing the asphaltene content and reducing the proportion of resins while maintaining the oil level. With an increase in the reaction duration and anhydride concentration, the oxygen content, average molecular weight and content of hydrogen atoms in the α-position to the aromatic nuclei and functional groups increase. An increase in the reagent concentration to 25 wt% and the duration of catalytic acylation to 8 h causes a significant decrease in the colloidal stability of the product. Optimum conditions for obtaining a product with high sedimentation stability (77-79 %) are achieved under the following conditions: the concentration of trifluoroacetic anhydride 25 wt%, synthesis duration 1 h.

Technogenic emissions from a number of large industrial enterprises for several decades have been determining the unfavourable environmental situation in the city of Angarsk (the Irkutsk region). This indicates the relevance of geoecological studies, allowing assessment of the anthropogenic impact on the components of the urban environment. The study presents the results of spatial distribution of dust load and concentrations of major elements (Fe, Al, and Ca) and trace ones (V, Co, Ni, Cu, Zn, As, Cd, Mo, U, Pb, and Hg) in the solid sediment of the snow cover of industrial and residential areas of Angarsk. It has been revealed that the mean value of dust load in the industrial area of the city is 141.6 mg/(m²•day), and in the residential area it is 108.8 mg/(m²•day), with the background level being 6.2 mg/(m²•day). The elements dominating in the industrial area are Pb, Cd, and As, their concentrations exceed the background levels by a factor of 23, 11, 10, respectively, and in the residential area Pb and As dominate (exceeding background concentrations by a factor of 15 and 10, respectively). The major sources of technogenic elements emissions are the Angarsk Cement and Mining Plant, the Angarsk Petrochemical Plant, and TPP objects. Geochemical mapping and factor analysis revealed associations of potentially hazardous elements in the solid sediment of the snow cover: Ca-Cd-Pb-Zn, As-U-Al, and Co-Ni-V. Pollutant elements spread from industrial sources over the residential area as a result of atmospheric transport. The mean values of the total index of potential ecological risk characterise the level of atmospheric air pollution in Angarsk as very high.

For the first time, the soluble products of pine wood peroxide catalytic delignification are proposed for obtaining chirosan-containing films. Chitosan biocomposite films were synthesised using microfibrillated cellulose (MFC), soluble peroxide delignification products (SDP) and glycerol as a plasticiser. The films were characterised by IR spectroscopy, X-ray diffraction analysis, scanning electron microscopy, differential thermal analysis, and their barrier properties were also studied. It has been determined by IR spectroscopy that film synthesis involves the formation of intermolecular hydrogen bonds between the COOH groups of soluble peroxide delignification products and OH groups of chitosan. The addition of 3.0 vol% MFC to the chitosan/SDP biocomposite film causes a 2-fold increase in its tensile strength and tensile elongation (up to 8 %). The obtained chitosan biocomposite films had reduced water vapour permeability and high barrier properties for UV radiation in the presence of both MFC and SDP. The obtained composite biofilms can be used as biodegradable packaging materials.

The methods for modifying the surface of mineral raw materials to obtain sorbents for water purification from oil and oil products are considered; a comparative analysis of the methods of material treatment with the modifying substances in the gas and liquid phases is performed; distinctive features are determined, including technological, economic and environmental aspects; the properties of sorbents are described. Evaluation of the methods shows that processing in the gas phase allows obtaining high-quality hydrophobic sorbents, but the technology requires using complex, specialised equipment, which significantly increases the production cost. Liquid-phase modification is relatively easy to implement, and the necessary equipment is available. However, the disadvantages of this method include environmental safety issues associated with the need to dispose of waste solutions. The article presents the authors’ own experimental studies, describes the developed process flow charts for modifying porous granular aluminosilicates, such as expanded perlite and vermiculite, expanded clay, and foam silicate. Results of the studies of the properties of sorbents obtained by modification in the gas/vapour-gas phases of hydrocarbon compounds, and the sorbents modified in an aqueous solution of sodium stearate showed the advantages of gas-phase modified samples in terms of sorption capacity values. In experiments on cleaning the surface of distilled, tap and sea water from diesel fuel with these sorbent samples, the efficiency reached almost 100 %, while liquid-phase modification ensured purification at the level of 98 %. The comparison of the two tested modification methods shows that the choice of the optimal approach is determined by the requirements for sorbent characteristics, operating conditions and features, as well as the cost and availability of resources for production.

The oxidative delignification of miscanthus was optimised regarding the parameters of catalyst used and the amount of acetic acid for cellulose extraction, and the effect of preliminary mechanical activation on the process efficiency was also studied. It has been shown that an increase in CH₃COOH content and the use of a ZrO₂•nH₂O catalyst improve the purity and yield of the cellulose product. Mechanical activation of miscanthus for 10 min reduces both the amount of residual lignin in the cellulose and its polymerisation degree. The membranes produced in this study match the thickness of separators used in energy storage devices. The uptake of electrolyte (6 mol/L KOH) observed in the sample obtained from an N,N-dimethylacetamide solution exceeds that of a separator produced by a similar method from microcrystalline cellulose.

Currently, the widespread use of surfactants in various fields, such as detergents, foam and emulsion stabilisers, fluorogens, hydrophobing agents, corrosion inhibitors, makes their synthesis one of the relevant tasks. The paper describes the results of the study of petroleum-collecting and petroleum-dispersing properties of quaternary ammonium salts formed from monobasic carboxylic acids of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), and palmitic acid in distilled, drinking and seawater contaminated with Balakhani crude oil (Azerbaijan). Surface-active properties of solutions of these complex salts with varying concentrations were determined using a tensiometer. The study of the composition of new complex salts synthesised under laboratory conditions by infrared spectroscopy proves that the reaction proceeds according to the proposed scheme. The complex salts formed by palmitic acid with MEA, DEA and TEA reduce the surface tension from 72.0 to 37.3, 35.5 and 34.4 mN/m, respectively, which means high surface activity. Different concentrations of quaternary ammonium salts formed by MEA, DEA and TEA with palmitic acid exhibit ambiguous effects as petroleum collectors and petroleum dispersants in seawater contaminated with Balakhani crude oil.

The macro- and microelement composition of drinking water from the centralised water supply and bottled water consumed by the residents of the Russian North (in the cities of Murmansk, Apatity, and Magadan) and by the residents of Moscow and Ulyanovsk as reference cities was studied. Water from the centralised supply system and bottled water in the northern regions is characterised by decreased concentrations of essential elements Ca, I, Mg (below the established standard for the physiological completeness of drinking water. At the same time, no chemical elements were found in these water samples at concentrations exceeding the maximum allowable concentration (MAC). In comparison with the northern regions, water from the central regions of Russia is reliably richer in B and K (p < 0.001), but the concentrations of these elements also do not exceed MAC. For tap and bottled water samples from Moscow and tap water samples from Ulyanovsk, an exceedance of the MAC was recorded for only one element: P.

The article discusses the synthesis and properties of 1-hydroxy-2-trifluoroacetylaminoanthraquinone 1, which can function as a selective colorimetric sensor for volatile biogenic amines. Compound 1 was obtained in two steps in 92 % yield, and its structure was confirmed by a set of physicochemical analysis methods, including X-ray diffraction. The association constant of compound 1 with triethylamine was determined using spectrophotometric titration, and the detection limit was measured. Polymeric sensor films were prepared by centrifugation. Their sensitivity to volatile biogenic amines during the decomposition of fish fillets was evaluated. The sensor demonstrated distinct colour changes corresponding to the degree of spoilage of the packed fish. Using colour spectrophotometry and a smartphone camera, changes in the colour of the polymeric sensor film were recorded upon contact with the analyte. This development demonstrates significant potential for the creation of polymeric sensors for the rapid and real-time detection of volatile biogenic amines.