Andrey Andreevich Gushchin

The paper compares the efficiency of oil products decomposition from the surface of an adsorption material, which was natural diatomite, consisting mainly of silicon oxide, using a coaxial and planar system implementing a dielectric barrier discharge. It is shown that plasma treatment of diatomite uncontaminated with oil products results in an increase in the sorption capacity, which means that in addition to the regeneration of the sorbent, its modification also occurs due to an increase in the surface activity of the sorbent. In the case of using a reactor with a coaxial arrangement of electrodes with approximately the same rate constant and rate of destruction from the surface, this reactor provides a higher sorption capacity after the treatment due to a higher access of active particles to the surface of the adsorbent in the system. Each cycle of the contaminated sorbent treatment in the reactors resulted in a decrease in its sorption capacity; however, even at the fifth regeneration cycle, the sorption capacity of the sorbent was higher than the initial capacity with both the coaxial and the planar system. Surface analysis and determination of the diatomite’s sorption properties, estimated from its specific surface area using low-temperature inert gas adsorption allowed us to construct liquid nitrogen adsorption/desorption isotherms on the diatomite surface after treatment. BET analysis of these isotherms revealed that the sorbent’s specific surface area and mesopore volume remained virtually unchanged, as before treatment. The adsorbent’s surface area also remained unchanged.

The paper presents the results of studies of the kinetics of decomposition of an aqueous solution of p‐chloroaniline (PCA) under the action of a dielectric barrier discharge at atmospheric pressure in an oxygen flow. The range of PCA concentrations was 10–150 mg/L, and the power density was 1.3 W/cm³. It was found that the decomposition of PCA proceeds formally according to the 1st kinetic order equation with a rate constant of (3.1–1.1) s^‐1. The energy yield of decomposition (number of decomposed molecules per 100 eV of input energy) was 0.071–0.38. Data on the kinetics of the formation of degradation products (NH₄⁺, NO₂⁻, NO₃⁻, Cl⁻, CO, CO₂, carboxylic acids, aldehydes), as well as the results of biotesting of treated solutions are presented.

Tube-type devices, including chemical reactors, are often key components of the manufacturing process and significantly influence its technical and economic indicators. Therefore, creating new, higher-quality designs of such reactors and finding optimal operating regimes are important scientific research tasks. Addressing advanced problems always involves the use of mathematical and computer modeling techniques. Due to the complexity of internal processes in such equipment, relatively simplified standard models are used. The study examines the possibility of creating a model of a tubular reactor using systems of discrete stochastic elements. This tool fully utilizes the paradigm according to which the individual behavior of system elements should determine the behavior of the entire system as a whole. Additionally, the created models take into account the influence of probabilistic components of the phenomena under study. The article considers both hydrodynamic effects and the progression of chemical reactions within a unified approach. The methodology for creating the model is described, and some results of computer experiments with it are presented. The outcomes of simulation modeling using the proposed approach are analyzed, demonstrating its potential for generating new data in the field of digital technology development in industry. For citation: Bobkov S.P., Astrakhantseva I.A., Gushchin A.A., Bobkova E.S., Astrakhantsev R.G., Shutov D.A. Using a discrete probabilistic approach for simulating flow tubular reactors. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 2. P. 96-101. DOI: 10.6060/ivkkt.20256802.7109.

The paper presents the results of the environmental impact assessment of the sludge pond for iron-containing waste generated as a result of the economic activities of the Zavolzhsky Chemical Factory located in the Ivanovo Region. In 2020, the sludge pond was included in the state register of objects of accumulated environmental damage. The accumulated sludge, with a volume of about 31 thousand m3, is a spent catalyst generated as a result of diphenylamine production. The main components of the waste are iron (III) oxide, silicon oxide and water, the total content of which is 95%. Heavy metals are also present in trace amounts - organic compounds, copper, nickel, zinc and chromium. The research assessed the quality of atmospheric air, the state of surface and groundwater, as well as the soil cover and soils on the territory of the site where the sludge pond is located. The assessments showed that the main negative impact is on the soil cover, groundwater and river Volga, flowing 185 m from the location of the object. To establish the quality of water in the Volga River, the hydrochemical index of water pollution was used, the value of which exceeded 10, i.e. the Volga River (in the area of the city of Zavolzhsk) according to the class and assessment of water quality belongs to the extremely dirty. In the area of the location of the object in the Volga River, there is an excess of heavy metals by 2-7 times compared to the background sample taken in the control section upstream. The quality of groundwater in the survey site does not meet environmental standards and varies from an emergency environmental situation to an environmental disaster zone. The value of the total indicator of chemical pollution of soils and grounds relates the studied area to the category of soil pollution as a high level of pollution (risk for the resident population). For citation: Izvekova T.V., Gusev G.I., Gordina N.E., Sitanov R.D., Gushchin A.A. Assessment of the impact of a sludge reservoir for iron-containing waste on environmental components. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 145-153. DOI: 10.6060/ivkkt.20246711.7140.

The destruction of naphthalene (NAP), one of polycyclic aromatic hydrocarbons, in its aqueous solution by treatment with atmospheric-pressure dielectric-barrier discharge in oxygen has been investigated. The range of NAP concentrations was 3.4–192.5 µmol/L, and the rms values of voltage and current were (6–13) kV and (0.1–0.8) mA, respectively. The oxygen flow rate was 3 cm³/s. The volumetric flow rate of the solution varied within 0.15–0.5 mL/s. It was shown that the degradation kinetics formally obeyed the 1st-order rate law with a rate constant of (2–3) s⁻¹ at an energy efficiency of 0.005–0.15 decomposed molecules per 100 eV of input energy. The degree of destruction achieved was 99%. It was found that the main degradation products are carbon dioxide (85% of the total carbon content) and aldehydes.

The paper presents the results of a study of the level of soil pollution in the city of Ivanovo with polycyclic aromatic hydrocarbons (PAHs). In soil samples, 13 of the 16 PAHs recommended for control by the US EPA were identified. Acetonaphthylene, acetonaphthene and indeno(1,2,3-cd)py-rene were absent from the priority list in the soil cover of the city. The total concentration of PAHs in the soil cover varies from 869 to 23343 mu g/kg, with a median value of 6805 mu g/kg. Analysis of the distribution of PAH concentrations relative to their molecular weight showed that the main contribution to the total content is made by PAHs with a low molecular weight, the contribution of which is about 80%. It was found that the sources of fluorene, chrysene, benzo(a)anthracene, benzo(a)pyrene, and dibenz(a,h)anthracene can be both local and transboundary. It is shown that the average total content of PAHs in the soils of the city is 50 times higher than the background level. Therefore, the main channel of their input is still local emission sources. It was revealed that the contribution of carcinogenic PAHs to their total content does not exceed 12%, with similar to 85% accounted for by benzo(b)fluoranthene, and the proportion of benzo(a)pyrene does not exceed 12.5%. An assessment of the values of individual carcinogenic and non-carcinogenic risks for the city population was carried out, which showed that the found values correspond to a negligible individual risk. The level of risks of carcinogenic effects in the population, which manifests itself when the soil cover is contaminated with PAHs, is commensurate with the magnitude of health risks from soil contamination with heavy metals, and for non-carcinogenic effects it is an order of magnitude lower.

Photocatalytic, plasma and combined plasma–photocatalytic processes were applied for the destruction of a model pollutant, Rhodamine B dye, in an aqueous solution (concentration of 40 mg/L). For this purpose TiO₂-pillared montmorillonite was used as a photocatalyst (characterized by X-ray analysis and low-temperature nitrogen adsorption/desorption). It was prepared by the method of intercalation of titanium hydroxocomplexes, including hydrothermal activation of the process and preliminary mechanical treatment of the layered substrate. The dielectric barrier discharge (DBD) plasma in the presence of photocatalysts increases the efficiency of dye degradation (100%, 8 s) compared to plasmolysis (94%) and UV photolysis (92%, 100 min of UV irradiation); in contrast to photolysis, destructive processes are more profound and lead to the formation of simple organic compounds such as carboxylic acids. The plasma–catalytic method enhances by 20% the energetic efficiency of the destruction of Rhodamine B compared to DBD plasma. The efficiency of dye destruction with the plasma–catalytic method increases with the improvement of the textural properties of the photocatalyst.