The paper considers the possibility of using forest industry waste as a basis for the creation of biofertilizers. Of the main types of waste, sawdust, wood chips and bark are the most discussed. Taking into account the minimal change in composition, they can be used for the production of biofuels, such as pellets or briquettes. In addition, they can be used for the production of compost and fertilizers. The review of patents with a brief description of the method of processing and use of wood waste in the field of biotechnology is given The most promising for today can be considered the use of these wastes for the production of biofertilizers (when enriched with microbiological crops, as well as in the mixed part with animal husbandry and crop production waste), as well as the possibility of recultivation of disturbed areas during logging.

Keywords: sawdust, compost, biofertilizers, forest industry waste, patent search, woodworking, microorganisms

The problem of atmospheric air pollution by dust particles, along with the formation of greenhouse gases, covers many countries of the world. To monitor the state of atmospheric air, expensive and cumbersome monitoring stations are traditionally used, for which state organizations are responsible. The use of inexpensive sensor particle sensors that will allow real-time measurements at the border of the sanitary protection zone of industrial enterprises and on the territory of the residential zone opens up new prospects in the field of atmospheric air research. Currently, about 10 thousand inexpensive sensors operate on the territory of 75 countries of the world, which causes the involvement of citizens in the collection of data on the state of atmospheric air. The presented technology for monitoring the concentration of fine particulate matter can replace the traditional measurement method, but the question remains of the value of the data obtained in terms of their accuracy. This article discusses the factor influencing the deviation of the readings of the inexpensive Nova SDS011 solid particle sensor. To do this, the sensor was tested in real environmental conditions, experimental dependences of the concentration of dust particles of no more than 2.5 micrometers depending on humidity were obtained.

Keywords: atmospheric air, PM2.5, Nova SDS011 sensor, dust particle concentration, monitoring stations, relative humidity

The article presents the technological aspects of obtaining solid synthetic hydrocarbons (paraffins) used to obtain and improve building materials. It is shown that a promising alternative to petroleum paraffins is the production of synthetic hydrocarbons from non-oil, including renewable carbon-containing raw materials. The main reaction conditions, synthesis catalysts, promoters that contribute to the maximum yield of a solid product, the prospects for the use of biomass, carbon-containing wastes, and carbon dioxide in the technology for producing synthetic hydrocarbons are considered.

Keywords: synthetic hydrocarbons, catalysts, promoters, building materials, modifiers

The article presents the results of experimental studies to study the effect of the hydrogen index of the medium on the iron-catalytic oxidation of hydrogen sulfide with air oxygen in a reactor with an ultrafiltration separator in the pH range from 6.0 to 10.0 at Fe(OH) catalyst doses3 – 100, 500 and 1000 mg/dm3. The results obtained make it possible to optimize the operation of one of the modern technological solutions in the field of preparation of ground hydrogen sulfide waters based on the method of iron-catalytic oxidation and ultrafiltration.

Keywords: hydrogen sulfide, iron-catalytic oxidation, air oxygen, iron hydroxide, membrane separation, ultrafiltration

The article considers examples of atmospheric air monitoring in linear and compact cities. The issues of atmospheric air pollution are considered, examples of components of pollutants coming from stationary and mobile sources are given. The analysis of the monitoring system of cities with different urban planning is carried out.

Keywords: linear city, compact city, highway, pollution, monitoring, monitoring posts, motor transport, gas pollution, exhaust gases

The features of the functioning of steel structures in an aggressive environment are considered, the results of a qualitative and quantitative assessment of the nature of damage to a profiled sheet are given.

Keywords: steel structures, building structures, corrosion, aggressive environment, zinc coating, corrosion rate

The article deals with the problem of disposal of the sludge formed after the treatment of wastewater at the production of chemical fibers. Sludge after sedimentation is stored in storages and pollutes the environment. We carried out a comparative analysis of existing methods of disposal of sewage sludge from chemical production, which showed that the most environmentally friendly way is pyrolysis. We have analyzed the chemical and fractional composition of ash sludge after pyrolysis. The analysis revealed that the resulting ash waste is similar to ash from coal-fired power plants, which makes it possible to use it as a microfill for paving roads or sidewalks. By selling the ash waste it is possible to reduce the payback period of the pyrolysis unit installation and reduce the ecological load on the environment.

Keywords: pyrolysis, sludge, sediment, ash, disposal

The paper presents the results of experimental studies on the effectiveness of complex electrochemical treatment using hydrogen peroxide for water disinfection. The effectiveness of the method for sanitary-indicative microorganisms has been confirmed. The most significant parameters for the disinfection process have been identified and a mathematical model has been developed based on them, which makes it possible to design industrial disinfection devices that are separate modules.

Keywords: disinfection of water, electrochemical methods, hydrogen peroxide, bactericidal effect, disinfection

The article assesses the impact of road transport on air pollution of roadside areas of a major transport highway in Volgograd. The road-car complex makes a significant contribution to air pollution by solid particles, significantly exceeding the background value. One of the criteria for assessing the impact of dust particles on the air environment according to the World Health Organization is the mass content of particles with a diameter of less than 10 microns (PM10) and 2.5 microns (PM2.5) in atmospheric air, which is normalized in the territory of the Russian Federation by hygienic standards. The fractional composition of dust particles entering the atmospheric air was assessed by the Microtrac S3500 laser particle analyzer, the concentration by the Lighthouse 3016-IAQ particle counter. The results of the dispersion analysis are presented in the form of the Rosin–Rammler–Sperling–Bennett function of the volume distribution of particles over diameters.

Keywords: dust, particle, dispersed composition, concentration, road transport, atmospheric air, transport highway

Due to the peculiarities of the technology, in gypsum production preference is given to dry cleaning of emissions into the atmospheric air from dust. At the same time, dust cleaning systems are arranged in multistage with installation of cyclones at the first stage, bag filters or electric precipitators - at the second. According to the results of research, it was found that the efficiency of cyclones in collecting gypsum dust is 70-75%, precipitators - 97.6-98.5%, and is insufficient neither to ensure sanitary and hygienic conditions, nor to reduce production losses. Based on the results of the studies, the median diameters of dust transported in the engineering and environmental system were determined: after the gypsum boiler - 25-58 microns; after the cooler - 38 μm; after the mill ring - 21 μm; before the electrostatic precipitator - 28 μm. To increase the efficiency of the dust cleaning system, it is proposed to replace the cyclone installed before the electrostatic precipitator with a block of two parallel dust collectors on opposite swirled flows. It has been experimentally established that the effectiveness of such a solution is 88.9-94.9%. Based on the results of studies and statistical processing of the data obtained, it was established. that the main influence on the efficiency of the dust collector unit is exerted by the relative volumetric flow rate in the flow sucked in the lower part of the main VZP apparatus. The highest efficiency values are achieved with its values 0.15-0.22. It was also established that the highest efficiency values are noted in the case when the diameter of the auxiliary VZP device is 2 times smaller than the diameter of the main one. Such mode and design parameters should be recommended for efficient operation of the plant.

Keywords: cyclone, electrostatic precipitator, dust collector at opposite twisted flows, dust collection efficiency, engineering and ecological system

The article deals with issues related to the operation of dedusting systems for technological equipment in the production of gypsum and gypsum building materials. The purpose of the research is to identify the features of the layout and operation modes of aspiration systems operated at existing enterprises. Data on the mass of dust determined from the results of measurements entering the working area from individual technological units are given. According to the results of measurements, it was found that from 10% to 20% of the mass of dust released in the technological process enters the working area. Examples of layout solutions for branched aspiration systems serving conveyors, transfer units, crushers of various types are given. It is shown that the reasons for their unsatisfactory work are the lack of aerodynamic linkage and insufficient volumes of removed air. The features of the layout and operating modes of the aspiration system from the gypsum boiler and mill are described. It is shown that individual sections of the system and the system as a whole operate in non-stationary modes, which is due to the variability of the flow rates and dustiness of the moving dust and gas flows.

Keywords: dustiness, dust emission, aspiration system, aerodynamic coupling, flow rate, concentration, dust and gas mixture

On the basis of the study, an analysis was made of the capacity of the roundabout according to the existing traffic intensity in the city, taking into account the composition of the traffic flow, the main factors affecting the passage of vehicles at the entrance to the self-regulated intersection are given. The possibilities of reducing congestion within the framework of the existing street and road network of the city are analyzed, conclusions and recommendations are given based on the results obtained.

Keywords: traffic capacity, traffic composition, roundabout, design speed, vehicle spacing, center island, load level, congestion, normalized traffic volume, number of lanes, service level

Air pollution in urban areas contributes to the development of various diseases among the population. In this connection, its environmental monitoring is relevant. Goals and objectives. The aim of the study was to study the redox potential of aerosols in the residential area of the village. Kuporosny (Volgograd, Sovetsky district) (experimental area) in comparison with the conditionally clean zone. The objectives of the study were to select aerosol particles in the leaves of apricot trees (Prunus armeniaca L.); preparation of aerosol suspensions from the leaves of apricot trees; study of the ORP of aerosol suspensions when they are infused for 5 minutes in distilled water; discussion of the obtained results. Methods. Leaves of apricot trees (Prunus armeniaca L.) in the amount of 10 pcs. placed in a glass dish, added 100 ml. distilled water, stirred them for several minutes with a glass rod to wash the particles from the surface of the leaves. As a result, aerosol suspensions were obtained, in which the ORP was studied. The ORP value was measured using electrochemical equipment (SevenCompact pH meter S220, manufacturer: Mettler-Toledo GmbH, Switzerland). Results. Established air pollution residential area in the village. Vitriol based on low values of the redox potential (Eh=30.03+0.27 (mV)) compared to the conditionally clean zone (Eh=140.83+0.81 (mV)). Conclusion. The results obtained indicate the predominance of recovery processes in the atmosphere of the residential zone of the village. Vitriol, the deterioration of its oxygen regime and the development of environmental risks for the population living there. In this connection, it is required to establish sources of pollution and develop appropriate environmental measures.

Keywords: aerosols, redox potential, environmental monitoring, residential areas, atmospheric air pollution

The article presents the results of theoretical and experimental scientific research on the problem of monitoring the safety of a coal-mining region at the stage of closing unpromising mines. To achieve the goal of research - the formation of an effective methodology for this problem - the following main tasks have been solved: - assessment of the negative impact of mining operations on the technosphere of the region; - selection of the basic characteristics of the natural-technogenic system; - comparative analysis of methods and technical and technological systems for environmental control. The authors of the article formulated the concept of a safe region and the hypothesis of its implementation. In particular, scientific and methodological approaches have been developed that provide an objective assessment of the results of research and the adoption of managerial decisions on the formation of a safe environment for the life of the population. The article shows that the effectiveness of the developed methodology in specific conditions is 85-90%.

Keywords: coal mining region, liquidation of mines, coal rock massif, methodology, natural-technogenic system, safety concept, proactive monitoring

The development of modern cities, caused by the need to improve the living environment, contributes to the creation of new buildings and structures. As a result, the density of typical urban development increases, mainly with rectangular buildings. Such buildings, with closed areas of courtyard spaces, create extreme microclimatic conditions and aggravate the air exchange of territories, thereby violating thermal and environmental comfort. This situation is especially acute in the southern cities. The article analyzes the influence of modern typical building on the microclimatic conditions of yard spaces. The factors influencing the formation of the heat and wind regime of urban areas have been identified. On the example of a building with a characteristic orientation for the conditions of Dushanbe, a graphical-analytical calculation of the duration of facade insolation was carried out. The role of insolation in the formation of convective flows of thermal origin is determined. On the basis of field studies, changes in the maximum speed of convective flows near the walls of the building were determined. The role of convective flows of thermal origin in the formation of the heat-wind regime of yard spaces is indicated.

Keywords: spherical buildings, ecology, energy consumption, energy efficiency, heat loss, air exchange, environment, enclosing structures

The article discusses a methodology for improving the energy efficiency of historical buildings that have objects of protection. The main ways of energy saving, which are revealed at the level of the microclimate of the premises, are also considered. The relevance of the topic is due to the complexity of performing work to improve energy efficiency if it is necessary to preserve the historical value of cultural heritage sites. The article proposes organizational and technological measures that allow optimizing costs by reducing losses of thermal energy, by modernizing heating, ventilation and air conditioning systems in the conditions of the historical development of the city of St. Petersburg.

Keywords: energy efficiency, construction organization, engineering systems, restoration work, historical buildings

The article is devoted to solving the problems of choosing a variant of the calendar plan in the complex development of residential microdistricts. At present, a methodology for linking construction and installation works in time and space is being developed, new methods for calculating the organization of work are emerging. Due to the constant change in regulatory requirements in construction, the essential characteristics of scheduling methods change. Variant analysis may include a sufficiently large number of indicators of the quality of the organization of complex development. Therefore, a method for comparing options and choosing the best one is proposed, which takes into account an unlimited number of indicators of the quality of work organization.  At the same time, different indicators can be taken into account for different regions, as well as new ones can be added. The effectiveness of the methodology is analyzed on the example of a residential area.

Keywords: residential area, variant analysis, flow organization of work, quality indicators, regulatory requirements

It is an undeniable fact that the environment and its biodiversity are severely disturbed and damaged by the unrestrained and uncontrolled use and disposal of non-biodegradable plastic waste. Growing concern about this problem is stimulating interest in studying the biodegradation of polymers such as polyethylene and polystyrene, etc., which are very stable in nature and cannot easily biodegrade. The decomposition of these relatively inert materials occurs in the environment depending on the presence of several environmental factors such as solar or ultraviolet radiation, heat, oxygen, water salinity, hydrogen index and microorganisms that can use these polymers as food. Humans can create conditions for artificial abiotic and/or biotic degradation of plastic waste. The article describes the directions of plastic degradation, the factors affecting biodegradation, and the chemical and physical properties of plastics. The authors reviewed several ways to biodegrade plastics in the environment and investigated methods to improve it.

Keywords: environment, plastic, biotic degradation, abiotic degradation, plastic packaging, plastic waste

The issues of developing a project for strengthening the building structures of a cable overpass after an emergency (accident) are discussed. On a real example, a description of the accident is given, the performance of work on the ghost of structures to the standard state is illustrated. The article was written on the basis of the completed research work No. 18-26.

Keywords: building structures, safety, cable trestle, emergency response, technical expertise, buildings and structures, metal structures, reinforcement project

Nitrogen oxides are one of the most common and toxic gaseous air pollutants of large industrial centers. The main difficulty of cleaning gas emissions is related to the dependence of the efficiency of the applied cleaning technologies on the NOx concentration, the frequency of emissions, the need for processing and/or disposal of products of interaction of nitrogen oxides with absorbers and regeneration of catalysts. The article analyzes the features of currently used and promising methods of cleaning waste gases from NOx, systematizes data on the effectiveness of such technologies. Based on the analysis of the processes of formation of nitrogen oxides, rational approaches to reducing NOx emissions in metal etching technology and electroplating are proposed.

Keywords: nitrogen oxides, biogenic and technogenic sources, catalytic and non-catalytic purification, selective purification, absorption purification, comparative efficiency

Acidic impurities in the atmospheric air pose a certain threat to human health and contribute to the development of various diseases among the population, which is an urgent topic of research. The acidity of aerosols in the residential area of the village was studied . Vitriol (Sovetsky district, Volgograd), located in the zone of operation of industrial enterprises (tannery, production of building materials, etc.) for the spring-summer period of 2022. The selection of aerosol particles was carried out using passive monitors - leaves of apricot trees (Prunus armeniaca L.) in the green infrastructure of the residential area of the village. Vitriolic. The study of the acidity index indicated the absence of acidic impurities in the atmospheric air of the residential zone, which corresponds to the normative values (pH = 5.5-6.5), (according to Svistov P.F., 2010).

Keywords: aerosols, environmental monitoring, residential areas, acidic impurities, pH

A methodology has been developed that can be used to develop calculation and instrumental methods for determining the standards for the accumulation of solid municipal waste for retail chains under common management, having a single trade and technological process, a similar range of goods for sale and carrying out separate accumulation of secondary material resources.

Keywords: accumulation of waste, municipal solid waste, generation standard, object of a stationary trading network, cluster analysis

The article presents the study results of a soil-like fraction contamination at a landfill located on the territory of the Traktorozavodsky district of Volgograd with heavy metals. The soil-like fraction's pollution level was assessed using a cumulative chemical pollution index (Zc) and its modifications. It was determined that the contamination levels with heavy metals are dependent on a used cumulative chemical pollution index modification. The use of the average geometric values of a cumulative chemical pollution index (Zc) is preferred for a pollution assessment of a soil-like fraction. Because the pollution level of a studied soil-like fraction was assessed as hazardous, its use as a recultivation material can only be permitted after a detoxification.The main pollutants in the soil-like fraction are cadmium, copper, and nickel.

Keywords: landfills, soil-like fraction, heavy metals, pollution level

Environmental monitoring of physical pollution of territories is carried out in various regions of the Russian Federation and abroad. Thus, the influence of, for example, radio frequency radiation on human health and ecosystems has been established. In this regard, the study of low-frequency fields of electric fields at the stage of pre-design work is relevant. The purpose of the study was to study the electric field strength (E,V/m) on the land allocated for horticulture in the DNT ""Luch"" of the Sredneakhtubinsky district of the Volgograd region in September 2021. Research objectives: measurement of the electric field strength; analysis of the obtained results; study of anthropogenic and natural sources of physical pollution of the territory; discussion of the obtained results. Materials and methods. The study of the electric field strength on a land plot allocated for gardening was carried out using a PZ-34 electromagnetic field parameter meter (Russia), which is registered in the state register of measurement systems (No. 64925-16) and is popular among other researchers. Research results. 30 measurements were taken. The data obtained (E=1.16+0.11 (V/m)) did not exceed the standards for residential areas. The median values of the electric field strength were 10-17 times higher than the median values of the studied indicator in comparison with similar rural areas in other countries of the world. Conclusion. These facts may indicate low-frequency pollution of the territory of a mixed type: an anthropogenic factor (highways, high-voltage power lines), a natural factor: a possible hidden mineral deposit, as a product of the post-volcanic activity of an ancient underground volcano in the Volga steppe zone, which requires further large-scale geological exploration of the study area and possible change in the status of the land.

Keywords: monitoring, electric field strength, horticultural associations, residential areas

In this paper, an experimental assessment of dust emissions from warehouses of building materials from the point of view of their impact on the air environment is carried out. The technological operation of placement, in which dust is formed in a closed warehouse, is considered. It was revealed that in the process of placing building materials, the source of dust emission is aeration lights and windows. The dispersed composition of emissions entering the environment from unorganized sources (windows, aeration lamps) was experimentally determined by the height of the room.

Keywords: closed warehouse, dispersed composition, dust emissions, aeration lamp, building materials