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Volume 72, Nº 5 (2017)
- Ano: 2017
- Artigos: 5
- URL: https://journals.rcsi.science/0147-6874/issue/view/10686
Article
The role of soil microorganisms in environmental and food security
Resumo
The review considers some problems of soil microbial system management, as well as the possibilities, constraints, and risks caused by environmental and food security problems. A natural microbial system, which obeys its own dynamic laws, is considered a required condition for the existence of a biosphere. Ignorance and disregard of these laws can lead to catastrophic consequences for the higher hierarchical system in which humanity acts.
191-198
Cadmium and arsenic adsorption in aqueous systems in the presence of monosilicic acid
Resumo
The effect of different concentrations of monosilicic acid on the sorption capacity of quartz sand, diatomite, zeolite, and brown coal with respect to cadmium and arsenic has been studied in laboratory conditions. The applicability of different adsorption models, including exponential, semilogarithmic, and linear dependences, as well as the Langmuir and Freundlich equations, has been compared. An increase in monosilicic acid concentration from 0 to 2 mM increased the sorption capacity of all materials. It has been suggested that either the interaction of monosilicic acid with a pollutant takes place directly in the solution followed by sorption of the reaction products on the surface or in the pores of the sorbent, or first adsorption of the monosilicic acid by the sorbent occurs followed by interaction of the sorbed silicic acid with cadmium and arsenic; it is also possible that both process proceed in parallel.
199-206
Application of humic substances in the remediation of heavy-metal-polluted soils of the Subarctic Zone of the Kola Peninsula
Resumo
The effect of humic substances of various origin on the behavior of heavy metals was investigated in a field model experiment on remediation of technogenic wastelands near the mining-metallurgical compplex Severonickel in the Subarctic Zone of the Kola Peninsula. Two distinct types of humates, coal and peat, were applied to the experimental sites in various doses and combinations with NPK fertilizer and lime. The combination of peat humates with lime proved the most effective for stabilizing heavy metals in a sixweek experiment. The application of coal humates in conditions of prolonged contamination, accompanied by suppression of vegetation and biota, is effective in small doses (0.5%) and, conversely, causes the mobilization of metals with an increase in humate concentration (1%).
207-214
Effect of water on the rheological properties of typical chernozem in Kursk oblast
Resumo
The rheological properties of typical chernozem were investigated by the amplitude sweep test on an MCR-302 rheometer (Anton Paar, Austria) for three water contents: maximum swelling, the liquid limit, and capillary rupture. A method is proposed for determining the water content of capillary rupture on an analyzer by using the curves for soil drying at constant temperature, determined simultaneously with the water content. Comparison of rheological soil characteristics at different soil humidity has shown that variations in the forms of soil water cause changes in the rheological soil behavior from viscous to elastic–brittle.
215-220
Changes in the chemical properties and characteristics of humus in soddy-podzolic soil due to main pipeline construction
Resumo
The multiyear dynamics of the acid–base parameters and humus characteristics of soddy-podzolic soil affected by main pipeline (MP) construction was studied. Distinctions between the properties of technogenically disturbed soil and soil unaffected by MP construction observed 1, 10, 15, and 30 years after construction have been characterized. The deterioration of physical and chemical properties and clearly displayed features of technogenic degradation of humus have been identified throughout the entire observation period.
221-227