DEPOSITION OF PRIORITY POLLUTANTS FROM MOTOR VEHICLE EMISSIONS BY SNOW COVER IN THE ROADSIDE SPACE

The microzone of chemical pollution is crucial for the level of environmental safety of road operation and their interaction with the environment – the transfer of pollutants generated by the combustion of fuels in engines and substances used in road maintenance by air and water. The chemical composition of exhaust gases entering the lower atmosphere in the human breathing zone is dangerous not only for human health but also for the formation of greenhouse gases. The environmental hazard of nitrogen compound emissions is caused by the formation of fine particulate matter (PM2.5) in the atmosphere and nitrogen deposition in ecosystems. Roadside snow cover is an extremely informative substrate for monitoring the level and characteristics of roadside pollution by motor vehicle emissions. It adsorbs emission components, which are identified in melted snow as nitrogen compounds – nitrates and ammonium ion, particles in the form of suspended solids, hydrocarbons in the form of petroleum products. These contaminants form an environmental hazard of surface wastewater generated on the roadside for soils and natural water bodies. The aim of the study is to experimentally determine the contamination of snow in the roadside area of urban and suburban roads by the main environmentally hazardous pollutants of exhaust gases immobilized in the snow cover: particles (suspended solids), hydrocarbons (petroleum products), and nitrogen compounds. An experimental study of the contamination of the snow cover in the roadside area with priority pollutants (ammonium, nitrates, suspended particles, petroleum products) from vehicle emissions was carried out. It was found that in the process of exposure of the snow cover, the concentration of all studied pollutants in it increased steadily compared to the content in atmospheric snow. With increasing distance from urban and suburban roads, snow contamination with suspended solids and petroleum products was negatively correlated. This demonstrates the level of anthropogenic load created by motor vehicle traffic in the studied areas. The concentration of nitrogen-containing compounds – ammonium nitrogen and nitrates – had a positive correlation and increased with increasing distance from the road. Thus, on the studied road sections, there was a simultaneous emission of ammonium nitrogen and nitrogen oxides, which creates a particularly dangerous environmental situation in urban areas due to the formation of PM2.5.