particulate matter

Purpose of the study is to determine spatial and temporal variability of PM2.5 air pollution level within urban geosystems with a high anthropogenic pressure (on the example of Kharkiv city). Methods. Open online monitoring platform «Air Pollution», PM2.5 level was measured with «7bit Pollution Monitor», statistical. Results. Monitoring of PM2.5 air pollution of Kharkiv was conducted from August 1, 2019 to April 1, 2020 at 6 control points in different districts of the city. Air Pollution open online monitoring platform served as a data source of 28,119 mass concentrations of PM2.5 in the air. Threshold concentrations, recommended by the WHO, were used to determine compliance with hygienic standards for fine dust of less than 2.5 μm. The PM2.5 air pollution level and its degree of threat to public health were assessed in accordance with the International Air Quality Index (AQI) scale. Fine particles pose the greatest health risk. Exceeding the PM2.5 threshold level set by the WHO was detected for 17.4% of studied cases (4,905 out of 28,119 studied cases). In general, according to the AQI scale, in the vast majority of cases, the content of PM2.5 in the air varies from low to moderate. The highest level of PM2.5 in the air was measured at point No. 1 at the address Aptekarskyi Lane 9, which may be due to its location in areas with high traffic. The daily, weekly and seasonal variability of PM2.5 content was de-termined. Seasonal and daily variations in the content PM2.5 of in the air of Kharkiv depend on changes in weather conditions (precipitation, wind speed, etc.), the level of traffic congestion and the operation mode of potential stationary pollution sources. Conclusions. The obtained results provide a basis for further study of the correlation of PM2.5 content in the air with the influence of various natural and socio-economic factors of the territory, as well as with the mortality rates.

Purpose. Increase in the efficiency of control of diesel particulate matter in the study of the operation of diesel particulate filters by taking into account their particulate composition. Methods. Analysis and synthesis of information in the study of the structure and properties of diesel particulate matter, mathematical modeling in assessing the effectiveness of control and neutralization of particles with soot filters, statistical processing of experimental data, a computational experiment in conducting a comprehensive assessment of the efficiency of the diesel particulate filter. Results. The structure, toxicological properties, dispersed composition and quantita-tive characteristics of diesel particulate matter are analyzed. The principle of the action of the particulate filter is described. The functions of the distribution densities of countable, surface and mass concentrations of solid particles of various fractions: nuclei, accumulation, large particles are considered. A method for the complex evaluation of the efficiency of a diesel particulate filter on the basis of indices of countable, surface and mass concentrations of particles has been developed. A complex analysis of the efficiency of the diesel particulate filter was carried out. Conclusions. The necessity of taking into account the dispersed composition of diesel solid particles in the analysis of their properties, rationing and the evaluation of the efficiency of the diesel particulate filter is substantiated. It was found that with a high efficiency of reducing the total mass of solid particles in the particulate filter - 93.8%, the amount, surface area and mass of fine particles with dimensions of 20-40 nm significantly increase - 4.2, 1.9 and 2.55 times, respectively. The increase in the relative fraction of fine particles after passing through the particulate filter is 72%.

Purpose. Creation of a national universal system of dynamic control of particulate emissions from diesel engines of different types – automobile, diesel, tractor, court and others on the basis of the measuring complex with the microtunnel MKT-2. Methods. Analysis and synthesis of information, mathematical modeling, calculated experiment. Results. The modern dynamic methods of control of emissions of diesel particulate matter are analyzed: Method for Real-Time Mass Microbalance, Tapered Element Elemental Microscopic Microbalance – TEOM, Quartz Crystal Microbalance – QCM and Laser Induced Incandescence – LII, their technical characteristics are determined. A schematic diagram of a dynamic method for controlling emissions of solid particles with an optical sensitive element has been developed. A procedure has been developed for determining the permissible degree of dilution of diesel exhaust gases by air in the tunnel. Conclusions. The technical capabilities of the microtunnel MKT-2 for environmental diagnostics of various engines have been determined. The recommendations on the creation of a universal system for the ecological diagnosis of transport diesels based on MKT-2 have been substantiated. It has been established ranges of variation of the dilution coefficients of exhaust gases in the tunnel are established for testing diesel engines corresponding to various norms of the Euro. The necessity of using a gas sample cooler in a tunnel is verified when controlling the concentration of solid diesel particles meeting the requirements of Euro-6 standards.