Biotesting of Kogalym City Soils in the System of Integrated Environmental Monitoring

Abstract

The purpose is to assess the ecological soil condition of Kogalym city using biotesting method in combination with the analysis of ecological, geochemical and microbiological indicators. Materials and methods. In June 2021, 53 soil samples were collected and analyzed within the city of Kogalym, along with 10 background samples taken 10 kilometers away from the city. Soil biotesting was conducted by assessing the dehydrogenase activity of the microorganism Dietzia maris AM3. The content of mobile, acid-soluble forms of Pb, Zn, Ni and Cu, the total population of cultivated heterotrophic microorganisms and the quantity of microorganisms involved in the nitrogen cycle (ammonifi ers, denitrifi ers, nitrifi ers, nitrogen fi xers) were determined. Results and discussion. Based on the results of biotesting, a high degree of toxicity was identifi ed in 15 soil samples collected from the Eastern and Northern industrial zones of the city. In the soils of industrial zones, reduced numbers of nitrogen cycle microorganisms were also found, along with the highest levels of accumulation of mobile forms of Ni and Cu. Correlations indicated the inhibitory eff ect of heavy metals on the development of denitrifi ers and the dependence of soil toxicity on their abundance. Conclusions. The results of biotesting of soils of Kogalym city and ecological, geochemical and microbiological analyses indicated negative changes in biological and geochemical properties of soils in industrial urban areas, highlighting the need for regular comprehensive monitoring.