Angelika Anatolyevna Astaykina
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Properties of water-soluble organic substances isolated from soils by centrifugation and vacuum filtration methodsMoscow University Bulletin. Series 17. Soil science. 2022. 1. p.26-33read more627
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Water-soluble organic substances (WSOM) of sod and humus horizons of Mollic Gleysol artificially saturated to full moisture capacity were isolated by sequential centrifugation from pores with a diameter of more than and less than 30 microns. The total concentration of carbon and phenolic compounds, the absorption and fluorescence spectra of the solutions do not differ significantly, but a strong variation in the parameters (the ratio of maximum and minimum values is 4 15 times) indicates the heterogeneity of the composition of the extracted substances. The concentration of simple phenolic acids in solutions of large pores of the humus horizon is 4 8 times higher than in smaller ones, salicylic, benzoic and cinnamic acids predominate (75% of the total amount). In small pores, p-hydroxybenzoic and benzoic acids predominate (67% of the total amount). Dissolved organic matter (DOM) of soil solution of the Podzolic soil (ELBTg horizon, moisture 22%), were obtained by tension lysimeters from pores with a diameter of more and less than 14.7 microns. DOM in solutions from large pores contain more C, N, phenolic compounds and, according to the absorption spectra, have a large molecular weight and a degree of aromaticity. Organic substances from small pores are more hydrophobic and are characterized by a greater C:N ratio; these features potentially promote DOM resistance to decomposition. Predominant localization of phenolic substances in large pores is favourable for the conservation in soil since transport with water flows assist their chemical stabilization in the lower horizons as organo-mineral compounds.
Keywords: pore diameter; tension lysimeters; soil solution; Gleysols; Retisols
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Ecotoxicity of urban dust: existing practices and perspectives for the bio assay application (review)Moscow University Bulletin. Series 17. Soil science. 2022. 3. p.3-19Olga V. Nikolaeva Svetlana. A. Klachkova Angelika An. Astaykina Elena V. Fedoseeva Vera A. Terekhovaread more641
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Bioassay is a popular method for the ecotoxicological state assessment of various components of urban ecosystems — soils, water bodies and air. However, little is known about the potential of bioassay application to determine the ecotoxicity of urban dust — a complex heterogeneous media composed of natural and technogenic particles.
Many components of urban dust are known to pose toxic eff ects to living organisms. The aim of this article is to review the existing practices for the ecotoxicological assessment of urban dust and to identify the key trends in the development of the bioassay. The existing studies revealed a high potential of bioassay methods as they are sensitive to a wide range of pollutants present in dust; able to refl ect the dust toxicity selectively depending on environmental factors, and can be implemented using organisms of diff erent trophic levels. The following dust characteristics should be taken into account for the bioassay method proper choice: sample mass, wettability, pH, water-soluble ions and organic matter content. Due to complexity of urban dust composition and diff erent potential for the transition of its components into water extracts, it is recommended to prioritize the bioassay realized on solid dust substrates
instead of extracts. For the comprehensive assessment of dust impact on urban ecosystem, a set of organisms of different
trophic levels should be considered instead of one. Standards should be developed for dust bioassay in order to unify the results obtained by diff erent researches. Th e choice of the control sample is one of the most important
methodological questions.
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