Ecological and geochemical state of soils and grounds of Moscow green spaces (analytical review)

The paper assesses the pollution of soils and grounds of green spaces in Moscow with heavy metals and de-icing agents. The analysis of literature sources indicates a decrease in integral pollution index of soils and grounds of green spaces in the city in recent years. The decrease in the integral pollution index is determined by the reduction of emissions from industrial enterprises and by the land reclamation with the replacement of the upper soil layer. At the same time, an observed increase in the lead concentrations in urban landscapes was caused by intensive automobile traffic. The lack of green territories was noted in central part of the metropolis, which is below the norm recommended by WHO (50 m2 of tree plantations per person). The processes of soil salinization and suppression of urban vegetation caused by the use of de-icing reagents are described. The literature data on the anthropogenic transformation of physical and chemical properties of soils and forms of heavy metal compounds in soils are presented. It is indicated that the study of these issues is promising for solving ecological-hygienic problems of the megalopolis. Soils of green spaces in Moscow are proposed to be divided into three groups, taking into account the genesis, ecological and geochemical state: 1) soils on artificial bulk ground of designed landscapes, 2) transformed soils with traces of past anthropogenic impact (postagrogenic soils, soils of post-settlement territories, 3) soils on the territories of parks, forest parks and forests, slightly affected by human activities and retaining the properties of natural zonal soils

The mass transfer of chemical elements and of their compounds in agrocenoses

The analysis of publications on the mass transfer of chemical elements in agrocenosis in the soil – plant system was carried out. Methods for estimating the content of mobile forms of chemical compounds coming from the soil into plants are considered. The phenomena of antagonism and synergism are characterized, and the necessity to consider them while planning fertilizer application is indicated. It is shown that the phenomena of synergism and antagonism of elements can be used in agriculture to regulate the flow of heavy metals or radionuclides into agricultural products. A balance model for mass transfer of chemical elements in agrocenosis is analyzed. It is shown that the introduction of organic fertilizers in soil mostly leads to a positive balance of microelements in the agrosystem. To characterize the efficiency of fertilizer use an assessment of the balance of nutrients in the agrosystem is required. The removal of trace elements by agricultural crops increases with the use of mineral fertilizers in doses that are optimal for the cultivation of crops in the region. In some cases, the input of heavy metals with technogenic fallout may exceed the removal of metals by plants from the soil. It may cause the accumulation of metals in the system. In uncontaminated background areas, the levels of microelement intake from fertilizers and atmospheric fallout in agrocenoses are comparable

PARAMETERS OF MATHEMATICAL MODELS FOR VERTICAL MIGRATION OF HEAVY METALS IN SOILS IN THE AREA OF LEAD AND ANTIMONY PLANT

The data on distribution of heavy metals in the soil profile (Yuan et al., 2017) of the province Guangxi in southern China in the zone influenced by lead and antimony plant were analyzed. The soil is sod-calcareous and rich in humus. The averaged over the years and depth (“apparent”) parameters of diffusion and convective-diffusion models of migration in the area of combined soil pollution (only soil aerogenic pollution and in combination with the sewage waters) are estimated. The largest values of the diffusion parameters were obtained for Zn and Cd (n∙10–7 сm2/sec), the smallest values were obtained for Pb and Sb (n∙10–8 сm2/sec). When soil was flooded by waste waters, a reliable convective component of migration for Zn and Sb was noted. At the same time the peak of Zn concentration moved to the depth of 40–60 cm. Under these conditions there was no clear inverse correlation between the migration mobility and the amount of sorption of elements by the soil

The using pilotless vehicle pictures for urban ecosystem soil-vegetable cover ecological condition estimating

A soil-environmental analysis of the urbanized ecosystem represented by the key site “Kurilovo” in New Moscow has been made using the images obtained by pilotless air-craft and modern GIS-technologies. In the course of this study the decoding of remote materials and field soil survey were conducted to describe the vegetation and soils; the geochemical analysis of soil samples was made with the aim at compiling an electronic ecological map of the area under study. These studies allowed us to specify the boundaries of the key area, to evaluate the vegetation and soil status in forests, residential and industrial areas as well as to identify the areas covered by contaminated soils

Possibilities of use of method of capillary electorphoresis while analyzing aqueous extract from saline soils

A comparative analysis of anions (Cl-, SO4 2-) and cations (Ca2+, Mg2+, Na+) detection in samples of saline soils by classical methods of titration (with use of atomic absorption analyzer Kvant-2AT for Na+ detection) and by method of capillary electrophoresis on Kapel-105 was performed. An analysis has shown limits of use of these methods as well as possibility of conversion of data obtained by method of capillary electrophoresis into data that could be obtained by methods of titration and atomic absorption. It was found that results of these methods correlate worse for anions especially for chlorides and better for cations. Largest divergence was noticed in areas of extremely low or extremely high rates of soils salinity. Functional relations (mostly linear or polynomial) between magnitudes obtained by different methods was found. The use of suggested equations of conversion gives an opportunity to compare results obtained by traditional methods (titration and atomic absorption) with those obtained by the method of capillary electrophoresis

The chemical composition in the salt excretion of <i>Tamarix ramosissima</i> under conditions of different soil salinity level

Being grown on soils with different salinity degree, Tamarix ramosissima as the major representative of crinohalophytes reveals its ability to accumulate and removal the soluble salts. This is evidenced by a conjugated analysis to determine the chemical composition of soluble salts in ground waters, salt crusts, plant tissues and the salt excretion covering the Tamarix ramosissima sprigs. In these studies the soils were represented by hydromorphic solonchaks with salt crusts 5 and 0.1 cm thick and the content of toxic salts accounted for 32.4 and 57.6 respectively. The salinity was sulfate-sodium by nature. Based upon a comparative analysis of definite anions and cations in plant tissues and the salt excretion it seemed possible to notice that their content in salt secreted is higher by 3.2-7.7 times as compared to that in plant tissues. There is much in common in the content of cations and anions in the salt excretion of Tamarix ramosissima that can be presented in the following way: Na+ > Mg2+ > Ca2+ > K+ и Cl- > SO42-. It has been also established that the maximal removal of Na+ and Cl- in the salt excretion doesn’t connected with the amount of given ions in ground waters. One should be assumed that the content of Na+, Ca2+, Mg2+ и SO42- is associated with the concentration of these cations in salt crusts of the studied solonchaks. It is worthy of note that the Cl- exudation is not dependent on its content in the ground water and salt crust being comparable with Na+ exudation. Thus, Tamarix ramosissima grown under natural conditions reveals no direct dependence between the ions exudation by plants in the kind of salt excretion, the chemical composition and the amount of salts in soil (salt crust) and the ground water