Геоэкологическая оценка загрязнения окружающей среды по биогеохимическим параметрам древесных растений (на примере г. Липецка)

Abstract

To conduct a geoecological assessment of the territory of the Lipetsk city, biogeochemical parameters of woody plants were used. Populus italica (Du Roi) Moench, growing in different ecological conditions, acted as an indicator species. Sampling of poplar bark was carried out at 21 points, including the background one. The laboratory determined the following biogeochemical parameters: acidity, ash content, content of chemical elements. During the summer period 2022– 2023 samples were taken and analyzed. According to the data obtained, the pH of the aqueous extract of the samples varied from 5.05 to 7.74 for different sampling points, the average value being 6.98. We have established a change in the hydrogen index of the Italian poplar bark towards alkalization. The maximum increase in pH was recorded in the area of the cement plant (7.74), as well as on the left bank, where Novolipetsk metallurgical plant production facilities are concentrated. The lowest indicator of acidity of the crust is typical for the recreational zone of park areas – 5.05. The ash content of Italian poplar peel in the territory of Lipetsk varied from 10.42 to 21.44%. We noted the minimum ash content in the Nizhny Park, the maximum parameter was recorded in the immediate vicinity of the Novolipetsk metallurgical plant production sites and in the zone of influence of the cement plant. Determining the amount of chemical elements in the Populus italica bark by the X-ray fluorescence method made it possible to establish a number of regularities. The selected samples have a high level of accumulation for a number of heavy metals. Copper was found at 11 points. In terms of manganese, the highest content was recorded in a sample of Italian poplar bark on the street. Diamond (330 mg/kg). At all points, with the exception of the Nizhniy park, there is an excess of background values. The concentration of zinc in almost all samples is high, more than 80 mg/kg, especially trees in the industrial and transport zone have elevated values of the indicator. The content of iron at all points in the territory of Lipetsk exceeds the background values (1.04 g/kg). The presence and high content of a number of chemical elements in the Italian poplar bark is explained by the fact that in addition to carbon, sulfur, nitrogen oxides, the composition of emissions from blastfurnace, sintering production, ferroalloys includes a large amount of dust containing particles of Fe, Сu, Ti, Zn, Pb, Cr and other heavy metals. A moderate correlation was established between the content of iron-titanium (r±mr=0.48±0.20) and iron-zinc (r±mr=0.47±0.20) in the Italian poplar bark. A high level correlation was recorded between the concentrations of iron and manganese (r±mr=0.80±0.14). Therefore, the use of tree bark to assess environmental pollution is a sensitive method that is used for geoecological monitoring.