Content Of Harmful Substances Research Articles

Nitrogen Removal Mechanism and Microbial Community Changes of the MBR Bioaugmented with Two Novel Fungi Pichia kudriavzevii N7 and Candida tropicalis N9

Ammonia nitrogen wastewater causes dissolved oxygen concentrations to decrease and the content of harmful substances to increase. To characterize the application properties of two novel strains of highly efficient ammonium transforming fungi—Pichia kudriavzevii N7 and Candida tropicalis N9—this study used both as compound microbial agents to treat nitrogenous wastewater. Here, we investigated the bioaugmentation effect of compound fungi N7 and N9 in the MBR bioreactor and the effect of N7 and N9 on the fungal and bacterial microbial communities in the system. The results revealed that in the first week after inoculation of N7 and N9, the average removal rate of ammonium in the experimental and control groups were 89.43% and 82.86%, respectively, and the NO3−-N accumulation concentrations were 12.56 mg·L−1 and 17.73 mg·L−1, respectively. The average transformation rate of total nitrogen in the experimental and control groups were 46.32% and 30.6%, respectively. ITS sequencing results indicated that N9 could be a dominant fungus in the complex MBR system. The results of 16S rRNA sequencing showed that the dominant bacterial communities in the system were changed by the inoculation of compound fungi. Therefore, the compound fungi can be applied to strengthen the treatment of nitrogenous wastewater due to its compatibility.

Імовірнісні моделі подання знань для підтримки прийняття рішень в умовах ризику та невизначеності на прикладі галузі охорони атмосферного повітря

In order to systematize and integrate the acquired experience necessary for decision-making in conditions of war and man-made danger, as well as for the purpose of controlling emissions of greenhouse gases or other harmful substances, knowledge presentation models have been de-veloped that take into account both the results of the analysis of available data and probabilistic assessments of the state safety of man-made enterprises and adjacent territories. In order to im-prove the decision-making process, a number of probabilistic models are considered, which are based on the calculation of subjective probability estimates regarding the occurrence of danger-ous events and forecasting the corresponding risks. Factors of various nature are considered during modeling: external influences, concentrations of harmful substances, greenhouse gas emissions, indicators of the state of safety of man-made productions, efficiency of equipment, accounting of violations, and other indicators. Also, the knowledge system provides for calcu-lating the risks of dangerous events, the probability of which increases under the interaction of two or a number of hazardous factors. On the basis of the conducted research, an algorithm for building and the structure of a probabilistic model of knowledge focused on software implementation in the decision-making support system for managing the safety of man-made enterprises that pose threats to the popula-tion and the natural environment has been developed.

Research on the distribution of harmful substances in automotive products based on chemical quantitative

At present, China's automotive industry lacks standardized standards and testing methods for conducting harmful substance testing and evaluation of products.This article finely disassembled a passenger car model and conducted detection and analysis of harmful substances. More than 320000 materials were tested, involving 85 assembly components. This article studies six harmful substances in automotive materials, including lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated biphenyl ethers. The content of harmful substances and their distribution in different materials and components are analyzed. This article provides technical reference for conducting hazardous substance assessments in the automotive industry through data analysis. The harmful substance mainly contained in the studied automotive product is lead, which is mainly distributed in materials such as copper alloys, aluminum, steel, solder, plastics, etc. The content of mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated biphenyl ethers in automobiles is generally low.

Impact of transportation on the environmental friendliness of agricultural food products

This article examines the impact of transportation on the sustainability of agricultural food products. To identify the impact of the transportation process on food quality, this study analyzed the content of harmful substances (nitrates) in several batches of potato fruits before and after the transportation process from the place of harvest to the place of storage. The measurements were carried out using an ecotester – a nitrate meter. The measurement was carried out in three batches of potato fruits collected from different agricultural fields. The results obtained allow us to assess the level of influence of transportation on the environmental friendliness of potato fruits. The results of the study are relevant for further research in the field of improving the quality and environmental friendliness of food products, including through optimization of their transportation processes, and can also be used in conducting broader research in the field of agriculture and ecology.

Использование комплексных органических удобрений при возделывании зерновых культур

In order to determine the effectiveness of the use of soils, laboratory studies were carried out in a mixture with various local agricultural ores, meliorants and waste from agricultural and industrial production, including microorganisms, macro- and microelements. The work was carried out as part of the implementation of a comprehensive project to create high-tech production, provided for by the Decree of the Government of the Russian Federation No. 218 dated April 9, 2010 on the topic "High-tech production of soils by innovative waste processing methods" (state contract identifier 000000S407521QL90002). In the introduction, the requirements for soils on the content of harmful substances are given. The research methodology contains objects, schemes of experiments, the place and conditions of their conduct. The results provide a detailed analysis of laboratory studies conducted with spring wheat and barley, with the reduction of biomorphometric indicators. The illustrations show the growth and development of the vegetative mass of plants. The conclusions reflect the results of the data obtained. The analysis of the average indicators of the two studied crops allowed us to identify 9 options for the subsequent selection of optimal components and ratios: Soil 75%+25 KOU%+defecate, Soil 75%+25 KOU%+phosphogypsum, Soil 75%+25 KOU%, Soil 50%+50 KOU%+phosphogypsum, Soil 50%+50 KOU %+zeolite, Soil 75%+25 KOU%+zeolite, Soil 75%+25 KOU%+ NPK, Soil 50%+50 KOU%+ NPK, Soil 50%+50 KOU%+defecate. Keywords: SOIL, COMPLEX ORGANIC FERTILIZER, BARLEY, WHEAT, MELIORANT, ZEOLITE, PHOSPHOGYPSUM, MYCORRHIZA, PLANT HEIGHT, PLANT MASS

Promotion of Ca2+ Accumulation in Roots by Exogenous Brassinosteroids as a Key Mechanism for Their Enhancement of Plant Salt Tolerance: A Meta-Analysis and Systematic Review.

Brassinosteroids (BRs), the sixth major phytohormone, can regulate plant salt tolerance. Many studies have been conducted to investigate the effects of BRs on plant salt tolerance, generating a large amount of research data. However, a meta-analysis on regulating plant salt tolerance by BRs has not been reported. Therefore, this study conducted a meta-analysis of 132 studies to elucidate the most critical physiological mechanisms by which BRs regulate salt tolerance in plants from a higher dimension and analyze the best ways to apply BRs. The results showed that exogenous BRs significantly increased germination, plant height, root length, and biomass (total dry weight was the largest) of plants under salt stress. There was no significant difference between seed soaking and foliar spraying. However, the medium method (germination stage) and stem application (seedling stage) may be more effective in improving plant salt tolerance. BRs only inhibit germination in Solanaceae. BRs (2 μM), seed soaking for 12 h, and simultaneous treatment with salt stress had the highest germination rate. At the seedling stage, the activity of Brassinolide (C28H48O6) was higher than that of Homobrassinolide (C29H50O6), and post-treatment, BRs (0.02 μM) was the best solution. BRs are unsuitable for use in the germination stage when Sodium chloride is below 100 mM, and the effect is also weakest in the seedling stage. Exogenous BRs promoted photosynthesis, and antioxidant enzyme activity increased the accumulation of osmoregulatory and antioxidant substances and reduced the content of harmful substances and Na+, thus reducing cell damage and improving plant salt tolerance. BRs induced the most soluble protein, chlorophyll a, stomatal conductance, net photosynthetic rate, Glutathione peroxidase, and root-Ca2+, with BRs causing Ca2+ signals in roots probably constituting the most important reason for improving salt tolerance. BRs first promoted the accumulation of Ca2+ in roots, which increased the content of the above vital substances and enzyme activities through the Ca2+ signaling pathway, improving plant salt tolerance.

Environmental approach to ensuring the security of modern enterprises

The development of integration processes and globalization requires an increase in enterprises' level of security. It becomes a necessary condition for their functioning. Issues related to the environmental and economic security of enterprises become relevant in modern conditions of rapid development of production and foreign economic relations and require further research not only at the level of the country but also at the level of regions and enterprises. Therefore, for enterprises, an essential point in their work is ensuring environmental safety without negatively impacting economic safety. Ensuring the enterprise's economic security is always important because it determines its ability to be stable on the market and flexible. Suppose the enterprise needs to pay attention to measures to counter environmental threats. In that case, it may lead to significant financial losses and even stop work. It is emphasized that the ecological component of the enterprise's economic security must guarantee the society's safety from business entities carrying out industrial and commercial activities. For this purpose, the manufacturer must carefully comply with the national norms of the minimum permissible content of harmful substances entering the environment and the ecological parameters of the manufactured products. It has been proven that enterprises' effective use of natural resources will contribute to producing quality products, increase competitiveness, and, most importantly, be environmentally safe for people's health. It is noted that an essential problem in ensuring control over the management system of the ecological component of safety is the reliability of the reported data of the enterprises' users of natural resources. It emphasized the need to introduce stricter requirements for environmental reporting by enterprises, which should lead to strict compliance with the norms and requirements of legislation in the field of ecology and, therefore, increase the environmental and economic security of the enterprise. Enterprise management is built on a balanced solution to environmental and economic problems, finding the optimal relationship between ensuring environmental safety and the expediency of enterprise activity. Keywords: ecological component, enterprise, safety, environmental economy, resources.

Pollutants production, energy recovery and environmental impact of sewage sludge co-incineration with biomass pellets

This study describes the production of pollutants, energy recovery and environmental impact of the co-incineration of sewage sludge and biomass pellets. The main objective of this study is to describe the use of energy generated by co-incineration and to assess the environmental impact of emitted pollutants. Co-incineration takes place in five different blended. The combustion takes place in a fluidised bed reactor with an average combustion temperature of 915–939 °C. The combustion process is mapped by Fourier transform infrared spectroscopy, Continuous Mercury Monitoring Systems, thermocouples, pressures, and flows sensors. The results show that the concentrations of harmful substances, namely SO2 and NOX, reach values of 12.39–1730.33 mg∙m–3N for SO2 and 93.30–1156 mg∙m–3N for NOX. This means that the emission limits are exceeded 40 times for SO2 and 8 times for NOX in the worst case. Regarding heat recovery, the resulting value of potential energy recovery from the flue gas is 5.35–7.69 MJ∙kg–1, and as the sewage sludge content in the fuel increases, the heat recovery value decreases. The resulting values of pollutant concentrations are also analyzed using a life cycle assessment approach using the GaBi software. The results show that sewage sludge incineration has the greatest impact on climate change, terrestrial ecotoxicity, and human toxicity. Again, as the sewage sludge content in the fuel decreases, the hazardousness of the discharged flue gas decreases. This study presents a relatively promising option to use sewage sludge as a secondary fuel in large combustion sources under certain conditions.

Requirements for the content of harmful substances in market products of plastics and rubber. Part IV. Toys

The article is a continuation of the existing legal acts review on the safety of products placed on the European Union (EU) market. The review, in part IV concerning the provisions on the control of hazardous substances in toys, covers both EU legal acts and national acts transposing EU regulations into Polish law in this regard.

Экологические аспекты при утилизации отработанных охлаждающих жидкостей

Purpose: To consider the issue of the state of the problem of collection, disposal and impact of used coolants on the environment, primarily from road transport. To show the need for recycling of spent cooling liquids, the search for new compositions of cooling liquids and the intensification of the collection of spent antifreeze from the population. Methods: Comparing the characteristics of main coolants, highlighting their advantages and drawbacks on the stage of efficiency reduction. Analysis of the types of contaminants accumulating in spent antifreeze. Comparison of advantages and disadvantages of typical methods for purifying spent coolants. Analysis of the growth of sources of anthropogenic impact in the considered area. Results: The most important characteristics of coolants have been established. The most characteristic types of contaminants contained in antifreeze are identified and the most suitable methods of their regeneration are given. The high relevance of the considered problem of the circulation of spent antifreeze as a result of the rapid growth of motorization of the population in the absence of proper control by the state is noted. The necessity of searching for new safe antifreezes while maintaining the target qualities of coolants is revealed. Practical significance: The necessity of revising the attitude to antifreeze in terms of assessing their danger to the environment is shown. The ways of improving the handling of waste coolant solutions in terms of intensifying their collection from enterprises and the public are outlined. It has also been noted that it is necessary to search for new solutions of cooling liquids with a lower content of harmful substances in them to protect humans and the environment.

Research on the Physical and Chemical Characteristics of Dust in Open Pit Coal Mine Crushing Stations and Closed Dust Reduction Methods

As an important link in open-pit mining production, the crushing station produces a large amount of dust during the production process. Dust has the characteristics of a wide spread area, great harm, and difficult governance. Therefore, dust control has become a key issue that needs to be solved in open-pit mining. In this article, we assess results after high-speed cameras and dust concentration detectors are installed around the crushing station to monitor the dust concentration in the surrounding air. It is found that in the air, dust with a particle size of less than 2.5 μm accounts for 67.43%, less than 10 μm accounts for 17.30%, and less than 100 μm accounts for 15.27%. In settled dust on the ground, particles with a particle size of less than 100 μm account for 42.69% of the sample, and particles less than 10 μm account for 16.60% of the sample. Secondly, physical and chemical properties testing is conducted on the dust. XRD test results show that SiO2 in the dust accounts for 65.80%; XRF test results show that the oxide Al2O3 in the dust accounts for up to 46.84%; ICP test results show that the element Al accounts for 42.62% of the total amount of trace elements detected; and Si accounts for 35.11%, clarifying the content of harmful substances to the human body. Finally, Fluent software, Ansys 2020 R1, is used to simulate the diffusion law of dust under different states of the crushing station, including an open state, a closed state, and the installation of a dust removal system. Based on the simulation results and the actual situation on site, the optimal dust reduction method suitable for the crushing station is proposed, and the diffusion law of dust under this method is simulated. The tracked dust shows that the dust removal efficiency of PM2.5 reaches 97.00%, PM10 reaches 99.60%, and TSP reaches 98.30%.

PRODUCTION ENVIRONMENTALLY FRIENDLY DIESEL FUEL BASED ON DEAROMATIZED DIESEL FRACTION AND BUTYL ESTERS OF FATTY ACIDS OF SUNFLOWER OIL

Currently, special attention is paid to the environmental performance of fuels, because, the ever-increasing quantity of transport leads to an increase in the emission of harmful substances into the atmosphere. In particular, for the introduction of environmentally friendly technologies for the production of diesel fuels, first of all, it is necessary to obtain diesel fuel with a low content of sulfur, nitrogen and polycyclic aromatic compounds, which requires the processes of hydrotreating, hydrocracking and hydrodearomatization are carried out, which require significant economic costs. The presented article considers an alternative process for reducing the content of harmful substances, in particular aromatic compounds in the composition of diesel fuel. The process of dearomatization of the diesel fraction was carried out using N-methylpyrrolidone as an extractant at a ratio of extractant : diesel fraction 2:1 for 6 hours. The physicochemical properties of the dearomatized diesel fraction have been studied. In the resulting dearomatized diesel fraction, the sulfur content decreased to 0.0220%, and the content of aromatic compounds to 0%, in addition, the fractional composition is facilitated, the density and viscosity decrease. In order to replenish the resource of diesel fuel, oxygen-containing additives were added to the dearomatized diesel fraction - butyl esters of fatty acids of sunflower oil in an quantity of 5-10%, and the physicochemical properties of the resulting compounds were studied. It was revealed that the addition of butyl esters of fatty acids of sunflower oil to the composition of the dearomatized diesel fraction favorably affects the quality indicators of the obtained compounds. So, there is an increase in the flash point by 6°C and the cetane number by 4-5 points, and the sulfur content decreases to 0.0198%. In addition, the diameter of the wear scar decreases by about 2 times and for a 5% compound it is 0.430 mm, and for a 10% compound it is 0.370 mm, which meets the modern requirements of the standard. Thus, obtaining environmentally friendly diesel fuel is possible by dearomatization of the diesel fraction with the subsequent addition of butyl esters of fatty acids of sunflower oil, which can be recommended as a multifunctional additive to diesel fuels.

Применение дезинфектантов нового поколения в решении современных проблем обеззараживания в водопроводно-канализационном хозяйстве

Purpose: To consider and evaluate alternative methods of water disinfection and disinfection of water supply and sewerage facilities and to select the most effective. To determine the possibility of using several agents at the same time, to select disinfectants with a biodegradable composition, the use of which will help reduce the negative impact on the environment. Methods: Comparison of the composition and effectiveness of existing disinfectants. Results: The necessity of using various combinations of disinfectants to reduce the likelihood of resistance in microorganisms to biocides is indicated. The most promising method for treating structures is the aerosol method, which allows achieving the necessary disinfection effect with small doses of the reagent. The use of multi-component disinfectants (such as the “Silver Bullet” anolyte and biocide) is safe for humans and the environment due to their composition, it also helps prevent microbial habituation to the substances. Practical significance: Due to the conditions of water intake changing for the worse and stricter regulations for the content of harmful substances in drinking water, the use of combined schemes for water disinfection and disinfection of structures has most potetial.

The current ecological and ichthyotoxicological state of the shlis-selburg bay lake Ladoga

The article presents the materials of biological and chemical-analytical studies of the Shlisselburg Bay of Ladoga lake, that plays an important fishery and sanitary-hygienic role as a source of water supply of St. Petersburg. The dominant role of ichthyo-fauna in the assay of the ecological and toxicological state of the studied water area is shown. The purpose of the conducted research is to assess the ecological and ichthyo - toxicological state of the Shlisselburg Bay of Ladoga lake, as one of the main fishery water areal and the only source of water supply of St. Petersburg (the source of the Neva River). Biological and chemical analytical studies of the water area of the Shlisselburg Bay in laboratory conditions were carried out in the summer-autumn period in 2022 in three water areas. A feature of the Shlisselburg Bay is the presence of a runoff flow, that initiates the removal of pollutants and the nature of bottom sediments, which makes the Bay less vulnerable to anthropogenic impact. Currently, the methods used to assess water quality for the fisheries perspective are biological – bioindication and biotesting, as well as the results of chemical analysis in comparison with the standards for the content of harmful substances in water, sediments, precipitation and fish. Preference is given to “express’ methods: biotesting and bioindication of fish research results. Analysis of materials from previous studies have given reason to consider a gradual decrease in anthropogenic load (exposure to pollutants) on fish, as generally recognized indicators of water quality, given from fisheries positions. The results of the research showed that the ecological and toxicological condition of the Shlisselburg Bay has now improved, but cannot be considered satisfactory. Taking into acount the state of the ichthyo fauna and the level of its pollution, it can be characterized as weakly expressed sublethal with a possible transition to medium-expressed, conditionally sublethal in the spring period.

Legislation on the Protection of Atmospheric Air as a Branch of Legislation

The importance of atmospheric air cannot be overestimated. Meanwhile, in most large cities, the state of atmospheric air does not meet the requirements of the legislation on the content of harmful substances. The article is devoted to the analysis of legislation on the protection of atmospheric air. It is necessary to determine the place of legislation on the protection of atmospheric air in the system of Russian law. The legal protection of outdoor air is distinguished by features that need to be reflected in legislation. There is currently little new research on this topic. Traditionally, legislation in the field of atmospheric air protection is included in the natural resource law. An attempt was made to justify the inclusion of atmospheric law in the composition of environmental law. In science, the question of the name of the legislation of the Russian Federation in the field of atmospheric air protection is debatable. The article contains suggestions on this issue.

Method and Algorithm of Autonomous Flight Trajectory Planning of an Unmanned Aerial Vehicle When Monitoring the Fire Situation in Order to Detect the Source of Ignition Early

The purpose of the research is to develop a method and algorithm for autonomous planning of the flight path of an unmanned aerial vehicle when monitoring the fire situation, which are designed for early detection of the source of ignition. Since timely detection of a fire source at the stage of its development allows to reduce both material and human losses, the development of a method and algorithm for autonomous flight trajectory planning of an unmanned aerial vehicle when monitoring the fire situation in order to detect the source of ignition early is an urgent, important task.Methods. A method for detecting the source of ignition is proposed. The method is based on three flight plans. Plan A provides for a flyby of the monitored area by gas with determination of the concentration of a harmful substance in each pixel of the monitoring area. When a pixel is detected in which the concentration of a harmful substance exceeds the threshold level, the flight control of the UAV is carried out through plan B, which provides for local planning to achieve the pixel target, which is determined by calculating local differential operators in a nine–element mask. Plan B allows the UAV to fly directly to the source of the fire and determine its coordinates. Flight plan C provides for the return of the UAV to the point of departure from any pixel of the monitoring zone.Results. An algorithm for controlling the UAV flight path has been developed, which allows determining local target pixels and building a local flight plan on this basis. The basis for constructing a local flight plan is the rule "at least three pixels on the tack", which allows you to obtain a nine-element matrix with known concentrations of harmful substances in the target pixel and determine those pixels of the local flight plan in which it is not possible to obtain this matrix.Conclusion. Mathematical modeling of the UAV flight control algorithm according to the proposed test method was implemented in the Matlab 8.0 package and showed control stability and high speed of reaching the coordinates of the pixel of the ignition source, exceeding the speed of achieving the set goal by 1.5...2 times, depending on the location of the ignition source relative to the direction of the flyby of the monitored territory.

INFLUENCE OF POINT SOURCES OF POLLUTION ON AIR QUALITY IN MAOPOLSKA FIRST TESTS OF A NEW VERSION OF FORECASTING OF AIR POLLUTION PROPAGATION SYSTEM

Polluted air is dangerous to human life and health. Particulate matter, among others PM10, isone of the most harmful substances. In Maopolska and its capital Krakw, the concentrations ofharmful substances often exceed the standards set by the World Health Organization. Krakw,thanks to the ban on residential heating with solid fuels, has significantly reduced emissions ofpollution, but they remain high in the remaining part of the region, affecting air quality in thecapital as well. With the frequent occurrence of high concentrations of pollutants, in addition tothe necessary measures aimed at reducing emissions, forecasting of air pollutant concentrations isneeded to inform the population if normative concentrations are likely to be exceeded. The FAPPS(Forecasting of Air Pollution Propagation System), based on the AROME/MM5/CALMET/CALPUFF model ensemble, has been operating in Maopolska since 2014 and has been used tocreate pollution concentration forecasts for Krakw and Maopolska. In this study, the influence ofemissions from point sources on air quality in Maopolska was investigated based on the results ofmodellingwith this system. Modelling results indicate that this influence is negligible. The qualityof PM10 forecasts for four versions of the FAPPS system, differing in the meteorological modelused MM5 (Fifth-Generation Penn State/NCAR Mesoscale Model) or WRF (Weather Researchand Forecasting) and the emission input (2015 emissions from the Maopolska Marshals Office,updated with data from the City of Krakw for 2018, or the 2020 emission inventory from theCentral Emission Database) was tested. The quality of forecasts was assessed based on the resultsof measurements at the 22 air pollution monitoring stations for three smog episodes that occurredon 1117.11.2021, 1115.12.2021 and 1318.03.2022. The best results for Krakw were obtainedusing an approach based on the WRF model and the emission inventory from the Central EmissionDatabase, for which an RMSE (Root Mean Square Error) value of 30.02 g/m3 was obtained forselected episodes. In the case of Maopolska, the lowest RMSE value (33.58 g/m3) was obtainedfor the system using the emission inventory obtained from the Marshals Office and the WRF model. First tests indicate that changing the meteorological model from MM5 to WRF can lead toimproved modelling results, but, further research is needed to confirm it.

Система защиты воздушной среды участка сварочных работ с применением восстановительной вентиляции

The technology is considered related to the protection of the air environment of electric welding areas with the use of restorative ventilation and showering. With the help of it, polluted air is removed from the working area and the conditioned air is supplied instead for meeting the requirements of sanitary norms for the microclimate parameters of working premises and the content of harmful substances in them. The traditional technology of air purification from welding smoke has fundamental disadvantages, the main of which is the inability to clean the air from carbon monoxide and nitrogen dioxide impurities. To normalize the microclimate of working areas, the volumetric air conditioning is used, which requires enormous energy costs. At the same time, the distribution of supply air does not provide for the protection of the welder from intense thermal radiation. The system of harmful substances suction from the welding station limits the freedom of the welder action. Therefore, in some cases, he is forced to raise the suction funnel above his head, as a result of what the welding smoke enters the room. It is proposed to avoid the above shortcomings by improving the system of complex protection of the air environment, containing an exhaust panel, an apparatus for cleaning and heat-moisture treatment of air with its cooling and subsequent return to the welder working area. It is advisable to use an apparatus for wet air treatment made according to the type of a packed scrubber-absorber using water with active additives of permanganate and sodium bicarbonate dissolved in it, which contribute to the dissolution and retention of toxic gases of the welding smoke in water. To increase the efficiency of air purification in this apparatus, it is proposed to use a special irrigated nozzle made of porous plastic plates, in which artificial turbulence of the air flow is carried out, which ensures its intense heat and mass transfer and temperature reduction. The use of such a device allows to implement an energy-saving technology by reducing the performance of the supply units to the minimum required level of outdoor air supply.

Methodology for assessing the dustiness of the air environment of the working areas of foundries

The content of harmful substances in the air is an important parameter of the working conditions of foundry workers. Due to the peculiarities of the technology, there are many sources of intense dust emission in the foundry. The distribution of dust concentrations in the atmosphere of the workshops was determined from the equation of the dust balance in the workshop room. The possibility of obtaining by calculation an objective picture of the distribution of dust in various sections of foundries is shown. Data from various studies were used to determine the density and dust at various sites of foundries. The results of the theoretical calculations show that in foundries, dust capture is an effective means of reducing the dustiness of the air of working areas.

Analysis of the state of the air environment in the underground parking

Preserving the ecological comfort of the urban environment forces architects to look for compromise solutions. One of them is the development of underground urbanism not only for transport infrastructures, but also for public buildings. In this case, environmental issues are relevant. The air quality in underground parking lots and in the adjacent area must comply with environmental standards. Underground parking lots are local sources of pollution. Therefore, during the construction of parking lots, design solutions should be carefully analyzed, especially ventilation issues. An effective method is mathematical modeling. The article considers the use of numerical simulation for the organization of ventilation using jet ventilation. The results of numerical simulation of a system of differential equations describing the processes of heat and mass transfer using a modern system of jet ventilation are presented. The use of jet fans makes it possible to ensure the permissible concentration of CO in the exhaust shafts. It is substantiated that the choice of locations for jet fans should be based on the analysis of velocity fields and concentrations of harmful substances. The article considers the features of jet ventilation in underground car parkings. The results of a numerical simulation of a system of differential equations describing heat and mass transfer processes using a modern jet ventilation system are presented using the example of an underground parking.