Volume 13, Nº 1 (2023)
Chemical Sciences
Molecular structure of substituted azoles, containing a biologically active heterocycle, and their complexes according to high-resolution NMR spectroscopy
Resumo
The structure and composition of many-electron molecular systems were analysed by nuclear magnetic resonance (NMR) spectra obtained from hydrogen and carbon atom nuclei, NMR 1H and 13C. In some cases, quantum chemical calculations were carried out. In addition to 1N and 13C, NMR spectra from other nuclei were also used. The spatial and electronic structure of molecules of various classes containing heteroatoms (nitrogen, oxygen, sulphur, silicon and phosphorus), as well as various functional groups, were studied. A series of papers deal with coordination compounds (diamagnetic and paramagnetic), as well as complex compounds of a donor-acceptor type. Parameter domains of NMR spectra — chemical shifts and spin-spin interaction constants — were determined, including the values of long-range spin-spin interaction constants characteristic of the azole cycle and well-known functional groups that make up substituted imidazoles and pyrazoles. It was shown that the indicated parameters can be used to establish the spatial and electronic structure of newly synthesized compounds containing an azole heterocycle. The study involved the analysis of NMR spectra 1H and 13C of solutions of 1-vinylimidazole complexes with manganese, cobalt, nickel and copper chlorides, as well as with organylhalogenostannanes (C2H5)3 SnX. In a solution of paramagnetic complexes of 1-vinylimidazole with chlorides of elements of the first transition group, the coordinating atom proved to have an octahedral environment, with four ligand molecules occupying the equatorial position. The structure of the diamagnetic complexes of this azole with organylhalogenostannanes is a trigonal bipyramid. A method for studying molecular structures based on NMR in paramagnetic systems is proposed. Examples (derivatives of 1-substituted azoles) of using NMR spectra modified by ultrafine interaction for solving various problems related to the structure and intramolecular dynamics of many-electron systems are provided.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):6-16
6-16
Polymerization of methyl methacrylate in the presence of tributylborane and aerosil
Resumo
In this work, we study the polymerization of methyl methacrylate in the presence of 0.3-1.2 wt% aerosil and the following initiators: dinitrile azo-bis-isobutyric acid together with tributylborane; dinitrile azo-bis-isobutyric acid together with tributylborane and 2,5-di-tret-butyl benzoquinone-1,4; tributylborane together with di-tret-butyl peroxy-triphenylstibine. Aerosil introduction alters the polymerization kinetics of methyl methacrylate and the respective IR spectra, indicating an increase in the proportion of syndiotactic polymer. This process is related to the orientation of the monomer and polymer on the filler surface due to adsorption by means of the carbonyl oxygen atom and silicon d-orbitals. Each initiating system has a particular effect on the kinetic curves. The polymerization of methyl methacrylate in the presence of tributylborane proceeds through coordination-radical polymerization in the coordination sphere of the boron atom. Additional coordination disrupts monomer coordination and slows down polymerization. The polymerization of methyl methacrylate in the presence of the tributylborane-p-quinone system combines the routes of coordination-radical polymerization and pseudo-living radical polymerization. The initiating system of tributylborane-di-tret-butyl peroxy-triphenylstibine is characterized by implementation of both physical and chemical adsorption mechanisms. The latter promotes the formation of a composite through covalent bonds between the polymer matrix (polymethyl methacrylate) and the filler (aerosil). An increase in the amount of aerosil up to 10 wt% leads to a corresponding change in the IR spectra of the composites. Laboratory samples were prepared to study the mechanical properties of composites and films. When filled with aerosil, polymethyl methacrylate demonstrate worse deformation properties, which is typical of composite materials. The microhardness of the material varies depending on the initiator used and the grafting type (physical or chemical), correlating with the kinetic data.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):17-27
17-27
Physico-chemical biology
Drug discovery: a new bioactive compounds isolated from natural sources
Resumo
A rise in mortality due to fungal infections in immunocompromised population has been observed lately. Nowadays, due to increased fungal infections, the limitations encountered in their treatment like resistance, side-effects and high toxicity, the rising over prescription and overuse of conventional antifungals all stimulate a search for alternative natural drugs. Therefore we are in dire need of natural newer strategies that involve reliable agents for the treatment of fungal diseases such as essential oils (EOs) are known for their anti-microbial properties and are multi-component in nature. Soil samples (66 samples) were collected from different agricultural fields and animals habitat of Saharanpur (U.P.). Isolation of keratinophilic fungi was carried out by hair baiting technique. Extraction of Mentha piperita and Cinnamomum vernum EO was carried out by hydrodistillation method and chemical composition of both extracted EOs was determined by Gas Chromatography-Mass Spectrophotometry (GC-MS). Antimycotic studies of EO was done by standard disc diffusion method. In the present study, the antifungal potential of M. piperita and C. vernum EOs was evaluated against three human pathogenic fungi isolated from the soil of agricultural field and animals habitat of Saharanpur (U.P.) i.e. Trichophyton mentagrophytes, T. tonsurans and T. equinum. The chemical composition of M. piperita and C. vernum EOs were analysed by GC-MS. Menthol (53.28%) was the major compound of the M. piperita EO followed by menthyl acetate (15.1%) and menthofuran (11.18%). Major constituents of C.vernum EO were linalool (8%), (E)-cinnamaldehyde (7.2%), β-caryophyllene (7.4%), eucalyptol (6.4%), and eugenol (5.6%). EOs of M. piperita and C. vernum have been found to have a remarkable and excellent antifungal activity against these pathogenic fungi. Present findings conclude that natural products like plant-derived EOs instead of chemotherapy and emergence of resistance to antifungal drugs can be regarded as an environmental safety mode of diseases control against pathogens.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):28-37
28-37
Synthesis of nanostructured bacterial nitrocellulose
Resumo
This work investigates an approach to the synthesis of nitrocellulose from bacterial cellulose. Bacterial cellulose demonstrates a high polymerization degree of 4600 and, according to SEM, consists of a dense network of nanosized microfibrils. IR spectroscopy identified functional groups corresponding to natural cellulose. Samples of nanostructured bacterial nitrocellulose were obtained in 156-159% yield by treating bacterial cellulose with an industrial mixture of 47-52% nitric acid and 34-38% sulfuric acid. The obtained samples proved to be completely soluble in acetone, which confirmed the formation of nitric acid cellulose ethers. The samples were found to have similar functional properties: the mass nitrogen fraction of 11.65-11.78%; the viscosity of 963-1282 mPas; the solubility in an alcohol-ether mixture of 12.9-14.1%. The conducted SEM analysis showed that nitration of bacterial cellulose leads to disorganization of the dense network of microfibrils. The production of nitric acid cellulose ethers was established by IR spectroscopy according to the presence of functional nitro groups. The methods of thermogravimetric and differential thermal analysis confirmed the high purity of the synthesized materials. The novelty of the conducted study lies in a comparative analysis of the properties of nitrocellulose samples synthesized from bacterial cellulose using different pre-treatment methods, as well as in the application of acid mixtures and nitration conditions different from those reported in literature. The obtained results indicate the feasibility of using nanostructured bacterial cellulose as a precursor of novel nitrocellulose materials for application in knowledge intensive fields and as an alternative to nitrocellulose obtained from plant cellulose.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):38-49
38-49
Effect of surfactants (sodium dodecyl sulfate, cetyltrimethylammonium bromide) on cell membrane permeability of red beet roots Beta vulgaris L.
Resumo
The paper considers the effect of two surfactants - anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethylammonium bromide (CTAB) - on red beet root Beta vulgaris L. Damage to root tissues of Beta vulgaris L. was assessed in terms of an increased release of electrolytes and vacuolar pigments of betacyanins from cells using conductometric and spectrophotometric methods, respectively. It was shown that SDS and CTAB do not impair the cell membrane permeability at concentrations of up to 0.05 and 0.005 g/l, respectively. An increase in the concentration of these surfactants led to a subsequent rise in the electrolyte and betacyanin release from the beet tissues, indicating the negative effect of the surfactants. A good concentration dependence was observed, i.e., higher concentrations of the studied detergents correlated with higher values of the electric conductivity and optical density of the incubation solutions. A significant toxic effect was noted when the test plant was treated with the studied compounds at a concentration of 1 g/l. Thus, two hours after the onset of measurements, the electrical conductivity of the aqueous solution, in which the beet roots previously subjected to 30-min treatment with 1 g/l SDS and CTAB solutions were incubated, increased to 42 and 81 yS/cm, respectively. These values exceeded the reference values by 89 and 272%, respectively. At the same time, the betacyanin yield exceeded the reference values by 327 and 805%, respectively. The experiments showed that SDS and CTAB increase the permeability of plant cell membranes of both plasmalemma and tonoplast. The tested methods proved to be fast (three hours response time) and efficient. These methods can be used to rapidly assess the effect of surfactants on plant bodies, to study the membranotropic effect of substances, and to control the breeding crop plants in terms of their resistance to unfavourable conditions.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):50-56
50-56
Improving an approach to lipase determination in enzyme preparations for the food industry based on a method of fatty acid production
Resumo
The production of enzyme preparations remains to be a promising and permanently growing direction of modern biotechnology. The industrial production of the most widely used enzyme preparations contributes not only to improving the existing technologies, but also to developing fundamentally new processes. In this connection, lipases as part of the processes of partial or complete hydrolysis of oils and fats present significant research interest. Lipases find application in food processing and consumer goods manufacturing, as well as in agriculture, medicine, and analytical practice. In this study, we compare three methods based on the reaction of hydrolytic cleavage of ester bonds in a fat molecule followed by the release of free fatty acids. The optimum parameters providing for the highest production of fatty acids were determined. A substrate to obtain a more stable emulsion under a higher accuracy of measurements was experimentally selected. The established optimum conditions for a biocatalytic reaction of substrate hydrolysis (olive oil) using the conventional enzyme preparation “Lipase” included the temperature of 40 °С, the pH of 4.7, and the duration of 20 minutes. In order to confirm the validity of the data and parameters obtained, comparative studies were carried out to determine lipase activity in various objects of microbial origin. When varying the dosage of the enzyme preparation, the lipase activity was found to be within 5% of measurement accuracy. This error agrees well with the conventional methods of determining the activity of enzyme preparations for the food industry.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):57-66
57-66
Mineral composition of the Nostoc commune soil cyanoprokaryota in the Baikal region
Resumo
The Nostoc commune Vaucher ex Bornet et Flahault soil cyanoprokaryote is a filamentous organism forming macroscopic colonies on the soil surface. This organism is capable of oxygenic photosynthesis and atmospheric nitrogen fixation, thereby contributing to the nitrogen and carbon balance of ecosystems and participating in the processes of disturbed soil recovery. The present study aimed to determine the content of mineral elements (Ca, Mg, K, Na, Cu, Fe, Mn, Zn, Cd, Pb) in N. commune thalli growing in herbaceous plant communities of the Baikal region in areas of various anthropogenic disturbance, and to establish the effect of soil acidity on the accumulation of these elements. The elemental composition was determined by emission flame photometry and atomic absorption spectroscopy. To the best of our knowledge, the accumulation of Ca, Mg, K, Na, Na, Cu, Fe, Mn, Zn, Cd, and Pb in regional samples of N. commune were determined for the first time. The investigated thalli were found to contain significant amounts of Ca, Mg, K, Na, and Fe. The species can be referred to calciphiles in terms of its ability to accumulate Ca (up to 27,440 mgkg-1 abs. dry weight) and to grow on neutral and alkaline soils. N. Commune outperforms vascular plants in terms of Fe accumulation (on average, 2112 mgkg-1). Significant differences were observed in the content of the studied elements in N. commune collected from different sites. N. commune thalli growing in the vicinity of a highway contained Pb, Cu, Zn, Cd, Ca, Mg, and Na in increased amounts. Under lower soil acidity, the species was found to accumulate more Ca, Mg, and Cd. Under increased soil acidity, N. commune thalli accumulate Fe, Mn, and K. A significant correlation between the content of these elements in N. commune and the acidity of the upper soil horizons was revealed.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):67-76
67-76
Lipid compositions for the prevention of hyperlipidemia and obesity
Resumo
Today, alimentary-associated socially significant diseases, such as hyperlipidemia and obesity, have reached epidemic proportions, thus requiring significant healthcare resources to combat the consequences. Prevention of these diseases, including by using specialized lipid compositions, seems to be a more effective and feasible approach. In this work, specialized lipid compositions for the prevention of hyperlipidemia and obesity are developed. The research was based on blending vegetable oils followed by stabilization with a natural antioxidant to increase the shelf life. The fatty acid composition of the obtained lipid compositions for the prevention of hyperlipidemia and obesity was studied by gas-liquid chromatography; the organoleptic, physical, and chemical parameters were determined by conventional methods. The shelf life was evaluated by peroxide and acid number. Soybean, low-erucic rapeseed, linseed, and camelina oils, as well as Schizochytrium sp. microalgae oil, were used. An oil extract of xanthophylls from Sargassum miyabei - a brown alga from the Far East region - was used as an antioxidant. The lipid compositions based on soybean oil were characterized by a higher content of polyunsaturated fatty acids compared to those based on low-erucic rapeseed oil (72.93-76.25% vs. 60.71-66.64%). In terms of organoleptic and physicochemical parameters, the developed lipid compositions for the prevention of hyperlipidemia and obesity meet the requirements of regulatory documentation. The introduction of an oil extract of xanthophylls from the Sargassum miyabei brown alga significantly increased the shelf life of the studied compositions (6 months compared to 3 months of control).
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):77-87
77-87
Effect of acrylate-based hydrogels on basic cultivation parameters and antagonistic activity of soil beneficial bacteria
Resumo
We study the effect of polymeric acrylate-based hydrogels on the growth and development of soil beneficial microflora, including nitrogen-fixing and phosphate-mobilizing microorganisms, entomopathogens and phytopathogen antagonists. The antibacterial effect of hydrogels (HG) was studied by the volume displacement method in Petri dishes according to Ye. Sagi. Bacteria were cultured in GRM broth; the optical density of the medium was determined at 600 nm at 1 h intervals for 48 h. The process of biofilm formation was studied in LB medium according to the method of O'Toole and Kolter (1998). HG samples were added to sterile medium at concentrations of 200, 100, 50, 25 and 12.5 mg/ml. The Paenibacillus polymyxa P and Agrobacterium tumefacience 204 strains, as well as the Bacillus thuringiensis 0271 and B. thuringiensis 0371 entomopathogens, showed no signs of inhibition in the interaction zone with both control and experimental HG. At the same time, the culture growth of the Azotobacter vinelandii 10702, Bradyrhizobium ottawaense M-8 and Rhizobium leguminosarum K-29 strains was inhibited in all the experiment variants. The investigated hydrogel suspensions HG1 and HG2 at a concentration of 200 mg/ml contributed to a decrease in the optical density of cultures of both B. amyloliquefaciens 01-1 and Lelliottia nimipressurales 32-3 by on average 23.3 and 14.7%, respectively, compared to the control. Introduction of HG2 into a nutrient medium in the amount of 25-100 mg/ml promoted active accumulation of biomass by P. polymyxa P and A. tumefacience 204. The HG1 and HG2 hydrogels at concentrations of 50-200 mg/ml and 100-200 mg/ml, respectively, enhanced the biofilm formation of B. amyloliquefaciens 01-1. The maximum stimulation of plankton culture and biofilm formation was observed when the P. polymyxa P strain culture was enriched with 12.5-100 mg/ml of HG1, which increased the intensity of bacterial suspension growth by on average 8.9 times compared to the control.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):88-98
88-98
Possibility the use biopreparations from coniferous raw materials in artificial reforestation of Scots pine
Resumo
Ecologically safe biopreparations for agriculture are obtained from the waste of natural raw materials - greenery (needles), which remains after large-scale logging operations. These products (fir extract and spruce extract) contain natural triterpene acids, plant phenolic compounds and flavonoids. Although the growth regulators with similar characteristics are used in forest nurseries, there is still no data about the seedlings growth that were obtained under the influence of these preparations and then planted in the forest. The goal was to study the effect of biological preparations on the Scotch pine growth when it grown in a forest nursery, and then, in the forest culture. The experiments with pre-sowing treatment of pine seeds and its planting were conducted in the forest nursery. Seeds were soaked in preparation solutions (doses of 0.1 and 0.25 ml/kg of seeds) for 6 h. After growing of pine trees in the nursery, plot with cultures from these seedlings was created in the forest. Before planting in the forest, the seedlings were measured (stem height, root collar diameter). Measurements of pine trees were also taken three years in a row in the forest plot (stem height, root collar diameter, increment). Shown that a once seeds treatment by biostimulants ensured high survival and adaptation of pine when it was transplanted into the forest. The biometric characteristics of young trees were higher in the third year than in the ones from the control variant. Concluded that biostimulants obtained from coniferous raw materials are recommended for Scots pine growing in nurseries and increasing the forest cultures sustainability.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):99-106
99-106
Prospects of a modified biofungicide based on Trichoderma viride for soil health improvement
Resumo
Trichodermin biopreparations isolated from Trichoderma viride are widely used for treating seed, vegetable, fruit and berry crops, as well as for soil application. A promising research direction consists in the simultaneous use of Trichodermin biopreparations and natural minerals, such as zeolite (0.2 and 0.04 mm), diatomite, glauconite and sapropel. Our laboratory experiments showed that these minerals do not inhibit the development of T. viride. While promoting T. viride growth, glauconite and diatomite application lead to its rapid sporulation. Zeolite in both fractions (0.20 and 0.04 mm) has a long-acting effect on T. viride growth. Sapropel prolongs the period of micromycete development to a lesser extent than zeolite in both fractions does. The studies were continued in a field experiment, where the micromycete composition of gray forest soils of Laishevsky district of the Republic of Tatarstan was evaluated after the application of a Trichodermin biopreparation. A biofungicide based on T. viride (at a dose of 3 kg/ha) was introduced into the soil together with the above natural minerals (at a dose of 0.5 t/ha each). Soil sampling for a quantitative and qualitative analysis of the micromycete community was carried out in the phases of germination and tillering of winter wheat (Sultan variety). Trichodermin contributed to a significant increase in the amount of T. viride in the soil. This genus was the dominant (74-100%) among other microscopic fungi present in the soil (p. Aspergillus, Mucor, Fusarium). T. viride was found to exhibit inhibitory activity against pathogenic fungi. Phytopathogenic fungi of the Fusarium genus were absent only in variants with the addition of zeolite (0.04 mm) and diatomite. The use of diatomite and zeolite together with Trichodermin preparations is a promising technique for improving the phytosanitary state of agricultural soils.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):107-114
107-114
A toxicological and biochemical model for assessing the ecological quality of agricultural products
Resumo
The development of organic agricultural markets is associated with a number of difficulties, including the lack of theoretical and practical knowledge in the field of organic farming. The application of enzymatic biotests in the toxicological and biochemical monitoring of agricultural products seems to be a promising direction. In this work, we develop a toxicological and biochemical model for assessing the ecological quality of agricultural products on the example of oilseed crops. The developed unified model includes a test-object, which is standardized according to the key physical and chemical parameters, a test-marker and a test-reaction, as well as a qualitative assessment technique. The latter is based on criteria for evaluating the impact of environmental factors in accordance with the selected detection methods. The developed model was tested on sunflower seeds. For lipase, which was established to be an organ-specific enzyme, the optimum conditions for a test reaction were determined, as well as the nature and conditions of the influence of est subjects. A method for determining the ecological quality of sunflower seeds based on changes in the activity of the organ-specific enzyme in comparison with the reference value was developed. The main analytical characteristics of the method were determined. The proposed model is characterized by a number of innovative features. Among them are the use of the object under study (an entire plant, seeds, fruits, etc.) as a test-object containing a test-marker with a specific test reaction; introduction of the ‘reference value' concept into the field of toxicological and biochemical assessment of agricultural products; introduction of the indicator ‘the dynamics of the activity of an organ-specific enzyme' relative to the reference value, which allows products to be characterized in terms of their ecological purity.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):115-123
115-123
Structure and sorption activity of larch bark treated with green reagents
Resumo
The paper describes the structure and sorption activity of larch bark following treatment with green reagents. The aim was to obtain sorbents from larch bark by means of chemical treatment. The study compared the effect of non-toxic and low-toxic extraction agents and reagents, such as water, hexane, ethanol and hydrogen peroxide, on the structure, sorption properties of the treated bark, as well as on the composition of the extracted substances. It was established that the process of bark extraction involves the transformation of its main components, leading to the formation of long-range ordered structures. The greatest structural changes were observed for the bark treated consecutively with ethanol and hydrogen peroxide, mainly due to the decomposition of hemicelluloses. Such treatment of the bark was revealed to contribute to the formation of a mesoporous structure. The methylene blue sorption of the treated bark is 6.5 times higher than that of the original bark. Studies of extracted substances using IR spectroscopy and GC-MS showed a similar composition of larch bark extracts obtained by aqueous and ethanol treatment, which contain mainly phenolic and alcohol compounds. In addition, the ethanol-peroxide solution contains esters and carboxylic acid derivatives. The hexane extract of larch bark was found to contain mainly terpenes and their derivatives, which are widely used as valuable components in medicine and have great potential as a source of biomaterials for green polymers.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):124-132
124-132
Chemical technology
Improving the performance of motor gasolines by optimizing their knock resistance distribution factor
Resumo
The growth of gasoline consumption worldwide is imposing stricter operational and environmental requirements on fuel quality. These requirements include not only a high knock resistance of gasoline, but also a uniform distribution of the octane number by fractions. The latter property is of great importance for reliable operation of the engine at variable modes. At the same time, most of the currently used oxygenates and additives produced on their basis exhibit a narrow boiling point range and are unevenly distributed over the fuel fractions. In this work, we study industrially available oxygenates, including methyl-tert-butyl ether, isobutyl alcohol, and a mixture of saturated hydrocarbons obtained in the process of sulfuric acid alkylation of olefins (alkylate). A composite mixture of alkylate, methyl tert-butyl ether, and isobutyl in the ratio of 50-70 wt%, 15-25 wt%, and 15-25 wt%, respectively, is proposed. This composition allows an equal increase in the octane number of narrow low-boiling and high-boiling fractions in the gasoline mixture, with the factor of knock resistance distribution being close to the maximum value of 1. The effect of the studied three-component mixture on the performance of respective motor gasolines was investigated. It was found that the addition of the studied mixture as a high-octane oxygencontaining fuel component in the concentration range from 25.0 to 45.5 wt% provides for a uniform distribution of knock resistance over the fractions and improves the energy efficiency of the fuel by increasing its specific heat of combustion.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):133-141
133-141
Kinetic curves of oil products sorption by calcined sorbent from ash and slag wastes of thermal power engineering
Resumo
Experimental research into dynamic sorption of model mixtures containing oil products was carried out. As a sorbent, dried and calcined ash and slag wastes accumulated by hydraulic ash removal at the ash disposal site of Novocherkassk State District Power Plant (Novocherkassk, Rostov Oblast, Russia) were investigated. The weighted portion of calcined sorbent for each model solution was fixed and amounted to 5.0 g. Model solutions were passed through a column filled with calcined sorbent. At the first stage, investigations were carried out to optimize the filtrate flow rate in the range from 0.05 to 2.5 dm3/min in increments of 0.05 dm3/min. Model aqueous solutions with pH=7.5 and containing 100 mg/dm3 of oil products were passed through the column containing 5 g of calcined sorbent. The optimum filtrate flow rate was 0.1 dm3/min at a maximum efficiency of oil products extraction from the solution of 84%. At the second stage, kinetic dependencies of sorption capacity and oil product concentration in the filtrate were plotted. To this end, experimental investigations into sorbent saturation with oil products by means of passing portions of model aqueous solution containing 10,000 mg/dm3 by 0.05 dm3 through the column filled with calcined sorbent in a quantity of 5 g and a filtrate withdrawal rate of 0.1 dm3/min were performed. The maximum value of sorption capacity was found to comprise 560 mg/g under the efficiency of oil products extraction from the solution of 85%. Following an analysis of the obtained experimental results, an approach to the mathematical description of the kinetics of oil products sorption was proposed. According to this approach, the concentration of oil products in the filtrate is calculated in two stages. At the first stage, the increase in the concentration of oil products in the filtrate occurs when the sorbent is saturated with oil products up to the maximum value of its sorption capacity. At the second stage, this increase is observed at the maximum value of sorption capacity. Kinetic equations for calculating sorption capacity and the concentration of oil products in the filtrate are provided. A satisfactory qualitative agreement between the experimental and calculated data was obtained.
Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2023;13(1):142-151
142-151