Heavy metal distribution in the soils and benthal deposits of the seym basin

Abstract

Benthal deposits form under climatic, chemical, physical, biological, mechanical, and hydrological influences in water bodies and their surfaces. An analysis of the benthal deposits is integral for assessing the pollution rate in a water body as it indicates the extent of an anthropogenic impact on it. However, the existing methods of benthal deposit analysis are highly underdeveloped. This research aims to estimate the heavy metal pollution in benthal deposits of the Zheleznogorsk region headwaters, Kursk Region. In order to achieve the set goal, the authors formulated the following objectives: (1) to assess the benthal deposit pollution rate via the regional St. Petersburg assessment method (1996); (2) to assess the benthal deposit pollution rate via pollutant threshold limit values for soils; (3) to identify the top priority pollutants of the benthal deposits in the researched headwaters; and (4) to identify factors of heavy metal flow in benthal deposits. The research results revealed the inadequacy of soil sanitary norms applied to benthal deposits. At the same time, the regional St.Petersburg method has broader possibilities of application in the assessment of benthal deposits. However, it requires adjustment to the environmental conditions of the Central Black Earth zone due to composition differences between soils and benthal deposits. The following metals exceeded the ambient content level in the benthal deposits of Zheleznogorsk region headwaters, Kursk Region: chrome, nickel, iron, and zinc. High iron content in rivers has been registered both in the proximity of the Mikhailovsky mining and processing plant [MMPP] and quarry and in headwaters located near the living areas of Zheleznogorsk far higher than the MMPP. All the water collection basins reviewed in this study demonstrated an even distribution of pollutants with no major divergence from the norm around the MMPP-related objects. However, the pollutant concentration exceeded the limit near all the living areas.