Assessment of technogenic pollution by silver compounds on the biological properties of the soil (Model experiment)

Tatiana  Minnikova; Natalia  Tsepina; Sergey  Kolesnikov; Natalia  Evstegneeva; Anna  Kuzina

doi:10.18502/japh.v9i4.17651

Tatiana Minnikova Department of Ecology and Nature Management, Academy of Biology and Biotechnology, Southern Federal University, Rostov on Done, Russia
Natalia Tsepina Department of Ecology and Nature Management, Academy of Biology and Biotechnology, Southern Federal University, Rostov on Done, Russia
Sergey Kolesnikov Department of Ecology and Nature Management, Academy of Biology and Biotechnology, Southern Federal University, Rostov on Done, Russia
Natalia Evstegneeva Department of Ecology and Nature Management, Academy of Biology and Biotechnology, Southern Federal University, Rostov on Done, Russia
Anna Kuzina Department of Ecology and Nature Management, Academy of Biology and Biotechnology, Southern Federal University, Rostov on Done, Russia

DOI: https://doi.org/10.18502/japh.v9i4.17651

Keywords: Soil Pollution; Silver nitrates; Silver oxide; Ecotoxicity; Sensitive indicator

Abstract

Introduction: Silver (Ag) has increasingly become one of the priority pollutants of soils, which is accompanied by a number of consequences for humans and soil biota. To fully assess the effects of the entry of different chemical forms of Ag into soils, it is necessary to conduct experiments with different types of soils, different exposure periods, as well as a wide range of biological indicators. The purpose of the study is to assess technogenic pollution by silver compounds (silver oxide (Ag₂O) and nitrate (AgNO₃)) on the biological properties of the soil in model experiment of the soil in a model experiment, followed by the use of the data obtained in the normalization of the Ag content in the soil.

Materials and methods: The effect of Ag₂O and AgNO₃ was investigatedin specific permissible concentrations of biological indicators of the state of Haplic Chernozems Calcic (HCC), Haplic Cambisols Eutric (HCE) and Haplic Arenosols Eutric (HAE). Ecotoxicity was assessed by the degree of changes in the indicators of enzymatic activity, microbiological and phytotoxic indicators of soils 10, 30 and 90 days after contamination. Activity of catalase it was determined gasometrically, dehydrogenases, peroxidase, polyphenoloxidase, ferrireductase, ascorbatoxidase, phosphatase, invertase, urease, protease was determined photocolorimetrically, the total number of bacteria by luminescent method, Azotobacter sp. abundance by the method of fouling lumps on the Ashby medium, length of shoots and roots of wheat (Triticum aestivum L.) morphometrically.

Results: It was revealed that Ag ecotoxicity was determined by the content of Ag in the soil, its form, the period from the moment of contamination and soil type. In most cases, AgNO₃ had a stronger ecotoxic effect on biological parameters. Phosphatase activity and number of soil bacteria are the most sensitive indicators. The activity of invertase, urease, dehydrogenases and Azotobacter sp. abundance are the most informative indicators.

Conclusion: Abundance is the most informative indicator. The results obtained to assess the ecotoxicity of soils contaminated with Ag, as well as the identified sensitive and informative indicators, can be used for diagnosis and as an indicator of the ecological state of soils.