The results of studies of the kinetics of the iron-catalytic oxidation of hydrogen sulfide by atmospheric oxygen in a reactor with a membrane separator are presented. The studies were carried out on a laboratory experimental complex. The dependences were obtained experimentally showing the effect of the catalyst dose - Fe (OH) 3¬, the pH of the medium, and the contact time of the water being purified with the reaction medium on the effect of water purification from hydrogen sulfide.

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

The publication considers "small" leaks of oil products in city Volgograd, which are mainly represented by gasoline leaks at gas stations and leaks of technical liquids from vehicles in parking lots. The properties of these leaks are investigated. The regularities of oil products entering the air from "small" leaks are obtained. Measures are developed to improve the efficiency of collecting leaks. The design of a container for storing and accumulating waste generated as a result of collecting "small" leaks of oil products is proposed and tested. The obtained test results showed that the proposed container design can significantly reduce atmospheric air pollution compared to the commonly used container design.

Keywords: oil products, leaks, properties of "small" leaks, gas station, parking lots, wastes, container, city

The article considers the content of dust particles in the filter of the split system of a residential building and in the air of an air-conditioned room, the material is taken, as well as its analysis for the content of fine dust.

Keywords: fine dust, residential air conditioning system, bacteria, integral distribution functions, "dissection"method

The problems of the organization of air exchange in gasified premises of residential buildings are considered. The requirements of regulatory documents for the definition of air exchange are given. The areas of ventilation grilles are determined based on two conditions. Recommendations are given for the implementation of a particular requirement in specific design conditions.

Keywords: gasified room, air exchange, triple air exchange, single air exchange, standard, ventilation channel, diameter, ventilation, exhaust, inflow, volume of the room, air velocity

The article discusses the constructive and conceptual solutions associated with the implementation of the main devices of the central air conditioner, working in conjunction with the chiller. The peculiarity of the implementation of these devices is dictated by the use of solar energy. The receivers of solar energy are solar collectors, in which the heating medium is heated, which is used as a heat source in the chiller generator.

Keywords: solar energy, central air conditioner, chiller, absorption refrigeration machines, vacuum solar collector

The article deals with the laws of distribution of pollutants in a linear city. The highest values of carbon monoxide concentration were determined in the near-main territories of the Krasnoarmeysky district of Volgograd. Also in this paper, the question of the dependence of the level of gas pollution in the mainline areas on various factors, which include human activity and natural, natural factors, is raised. The influence of temperature inversions on the speed of pollution propagation and their limiting value in various points of the city is considered. For the experimental part, 18 points of technical measurements of CO concentration were taken, during which compliance with the MPC standards of the samples taken was revealed.

Keywords: linear city, district, law of distribution of carbon monoxide, transport of impurities, air pollution

The article is devoted to the study of heat losses when heating infiltrating air entering through existing leaks, cracks in doorways of walls, gates, and window bindings. Various methods for determining heat loss through enclosing structures are considered. As a result of the thermal imaging study, a method for determining the heat losses for heating the infiltrating air through existing leaks is proposed.

Keywords: air consumption, infiltration, heat losses, leaks, enclosing structures, air permeability, microclimate

The authors of the work analyzed the successive stages of the process of reducing air pollution in the working area and atmospheric air, built a physical model of the process for reducing air pollution and selected the preferred options for the efficiency of dust suppression technologies in relation to the operating conditions of the drying drum of a brick factory.

Keywords: inorganic dust, dispersed system, construction industry enterprise, labor protection, environmental safety, brick production, drying drum, physical model of the process of reducing air dust pollution

The study is set to determine room's air exchange scheme's influence on exhaust ventilation appliances' effectiveness. Open-type exhausts (exhaust ventilation hoods) used in different industrial manufacturing processes are selected. In particular, a food processing working space with an adjacent meat heat-treating chamber, where ventilation hood is installed near an open doorway, is evaluated. Two options of supply air ducts' installation (air inflow in the center of a working space or, alternatively, side areas of it) are analysed. Geometrical models of heat-treating chamber, raw material loading room, ventilation hood placed over chamber's door, and supply air duct with air-distributing appliances are constructed. The article presents results of numerical simulation for the model of heat-treating chamber's exhaust ventilation system operation. It is established that, in case of a supply ducts' installation in a side areas of a room, an air exchange could be lowered by 28% under condition of a removal of a gas-air mixture without breaching into the room.

Keywords: exhaust ventilation, ventilation hood, simulation, heat-treatment chamber, numerical experiment

The article considers examples of cities with a linear-elongated configuration. Issues of air pollution are considered, examples of components of pollutants coming from stationary and mobile sources are given. Statistical data on human diseases in the Volgograd region for the period 2008-2017 are presented. Considers the issues of monitoring for the city of Volgograd.

Keywords: linear city, highway, pollution, carbon monoxide, monitoring, monitoring posts, disease statistics, combined action, vehicles, noise, gas pollution, health, exhaust gases, length

The article is devoted to the mathematical modeling of a multifunctional air pressure probe for avionics systems. The stages of the preparation of mathematical models and their application for the study of the measuring device are considered, the error of the determining the altitude-velocity performance at various angles of attack of the airflow is calculated. Conclusions are drawn on the practical significance of the results obtained and the perspective for the development of mathematical models and their application for the development and study of aviation instruments. ANSYS CFX software was used for modeling and engineering calculations.

Keywords: air pressure probe, multifunctional air pressure probe, mathematical model of the air pressure probe, mathematical model of the multifunctional air pressure probe, air data system, altimetry, airspeed, angle of attack sensing, angle of sideslip sensing

To assess the impact of various groups of sources of emissions in urban pollution, there is a method that can be called the main one - the assessment of the contribution to total gross emissions. But this method does not take into account the significant features of dispersion of pollutant emissions in the atmosphere, as well as the specifics of the mechanisms of formation of concentrations of pollutants at a specific point in the city and the calculation of complex indicators of the level of air pollution in urban areas. The authors proposed a procedure for calculating the atmospheric pollution index for source groups using the “summary calculations” tool. The calculations were carried out on the licensed software product "Ecologist-city". Based on the calculations, conclusions were drawn on the reliability of determining the influence of various groups of emission sources on air pollution in the city of Krasnoyarsk, based on the assessment of contributions to the total gross emission in the city.

Keywords: atmosphere, air, ecology, ecology of urban areas, environmental safety, summary calculations, IZA

A method for remote determination of the angular velocity of rotation of the blades of a wind generator based on digital processing of the video stream of this wind generator is considered. The main problems that are encountered with this method of measuring angular velocity are analyzed. The considered method for determining the rotation speed of the blades of a wind generator is possible provided that the frame rate is several times greater than the determined rotation frequency. The minimum possible error of this measurement method was found; the real error of measuring the angular velocity was calculated on a specific example.

Keywords: digital processing of the video stream, image stabilization of the wind generator, finding the contours of the rotor blades, estimation of the angular speed of rotation of the rotor

The possibility of increasing the reliability of assessing air pollution through the use of probabilistic methods is shown. Evaluation of quality indicators on a quantitative basis made it possible to find an error of the first and second kind in assessing the quality of the atmosphere. Based on the Bayesian approach, dependencies were obtained for estimating and predicting atmospheric pollution in the area of ​​a city that does not have a stationary post, based on data from stationary posts in other areas.

Keywords: atmosphere quality, reliability of the estimate, probabilistic methods, quantitative characteristic, error of the first and second kind, Bayesian approach, a priori probability, posterior probability, likelihood of a quantity

The equations of multiple regression of air quality from factors affecting external sources of emission in the urban environment are obtained. A prototype of a forced air supply ventilation valve with air purification, placed in the outer wall of the building, using various sorbents together with a photocatalytic filter (a thin porous plate coated with titanium dioxide next to two UV lamps, UV-A range, 365 nm, 6 W each) was developed. Full-scale studies of five options for purifying the supply air were carried out. High quality of outdoor air purification from pollutants has the following options: shungite; zeolite; silica gel; photocatalytic filter, its purification efficiency was 96.39-99.98% for carbon oxide (II), 96.39-97.89% for phenol, 95.76-97.78% for formaldehyde, and 93.97-95.12% for aliphatic hydrocarbons (C1-C5). The results obtained can be used in multi-storey construction.

Keywords: forced air supply valve, prototype, pollutants, sorbent, shungite, zeolite, silica gel, photocatalytic filter