Transformation of Urbanozems in the Areas of Gas Stations

Abstract

The areas near gas stations are places of local specific environmental pollution. The purpose of this work was to study the environmental consequences of gas station functioning on the surrounding soils (urbanozems). The content of oil products (OP), bulk and mobile forms of heavy metals, acute toxicity (Ceriodaphnia affinis Lillieborg, Раramecium caudatum Ehrenberg, Escherichia coli Migula), chronic toxicity (C. affinis), and the state of soil microphotrophs were determined. The content of OP was from 520±130 to 4820±100 mg/kg, which is significantly higher than the concentrations of OP in the soils of the transport zone of cities. The exceeding of the Russian standards for HM was found only for zinc (the maximum for the total form -1.7 MPC, for the mobile form -1.4 MPC). The urbanozems samples did not have acute toxicity; however, chronic toxicity in the bioassay for the mortality of C. affinis (up to 85%) and a decrease in the fertility of crustaceans (2-3 times compared to the control) were observed. In the structure of the community of soil microphototrophs, cyanobacteria dominated both in biomass and in abundance: (up to 748±10 thousand cells/1 g of soil) compared with green algae and diatoms (1.1-5.5 and 1.2-19.8 thousand cells/1 g of soil, respectively). As a result of the work, it was concluded that the quantitative algological analysis and biotest with the assessment of chronic toxicity in terms of mortality and fertility of C affinis for the diagnosis of local soil contamination in the areas of gas stations were of the highest informative value.

The procedure for selecting bioassays for different types of pollution

“…In this paper, we do not present intermediate results of bioanalysis of each sample, since our task is to describe the algorithm for the targeted selection of bioassays and to generalize analytically many series of experiments. Most of the results of individual experiments have been published, including a comparison of the sensitivity of bioassays to mineral forms of phosphorus (Kondakova et al, 2014), oil products (Olkova et al, 2017), mineral forms of nitrogen (Olkova and Makhanova, 2018), herbicides (Olkova and Berezin, 2018), and heavy metals (Olkova, 2020).…”