Potentially toxic elements (PTE) in soils on the megaprofile Eastern Donbass – Azov sea

An expedition was carried out to take soil samples of Eastern Donbass and other districts of the Rostov region. The main goal was to study the distribution of potentially toxic elements (PTE) in soils. The total content of mineral components in solid-phase samples was determined by using the X-ray fluorescence method. It was found that, according to the average concentrations, PTE`s line up in the following series: Fe>Mn>Zn>Cr>V>Cu>Ni>Pb>Co. The contents of Zn and Cu in the soil were compared by seasons. It was determined that PTE concentrations in the upper layer of soils were higher in winter than in summer. Geochemical spectra were constructed. They demonstrated that the concentration Clarks of Cr, Cu, Zn, Co, Pb exceeded the Clarks of these elements in the Earth’s crust. Against this background, Pb stands out with contrast, the concentration in the soil of which exceeds those in the earth’s crust by 2.8 times. The tightness of the relationship between the content of PTE in soil samples was calculated, which turned out to be a high straight line

The use of chemical and instrumental methods in the study of the forms of occurrence of sulfides in bottom sediments

On the example of the estuary of the Mius River - the mouth of the Mius River, the Mius estuary, the Taganrog Bay of the Azov Sea, a complex of chemical and instrumental methods was applied, including those developed by the authors. This made it possible to study the physicochemical parameters, the content of total hydrogen sulphide, the form of occurrence of sulfides, the total content of iron and their behavior in the bottom sediments of early diagenesis. Bottom sediments were formed at negative Eh values. Sulfides in bottom sediments are mainly in the form of molecular hydrogen sulfide and acid-soluble iron sulfides. The content of total hydrogen sulfide varied within wide limits, reaching 3.2 mg/g of wet weight, and of gross iron - from 25.4 to 45.1 mg/g dry weight. A significant relationship was found between the content of sulfide sulfur and gross iron. The presence of hydrotroilite was identified by the typical smell of hydrogen sulfide, black color, oily sludge, lack of magnetic properties and by visual study of its formations using electron microscopy. Under a microscope, images of coacervates (colloidal accumulations) of hydrotroilite of a round-ellipsoidal shape (lenticular), from gray to black, mercury-like, were obtained in a wet preparation. It was established for the first time that hydrotroilite exists in the natural environment as a gel-like substance capable of moving in the bottom of sediments. Upon collision, small formations coalesced into larger globules. The important role of hydrotroilite as a mercury accumulator in the early diagenesis of bottom sediments is shown

Physical and chemical properties, elemental and material snow composition in Rostov-on-Don

To study the current distribution of the heavy metals (HM) levels and iron in the atmospheric precipitation in Rostov-on-Don, an expedition was conducted aimed at simultaneous river water and snow sampling in the Don River, the roadside and park areas. The pH values of the melt-water were characterized by a slightly acidic reaction, and the stale snow in the park had lower values in comparison with the fresh snow. The river water was slightly alkaline, and the concentrations of dissolved migration forms of Pb, Cd, Zn, Ni, Cr, Mn, and Fe did not exceed the MPC. The exception was the Cu content, which exceeded the MPC by 2.4 times. The contents of the dissolved migration forms of Pb, Cd, Zn, Cu, Ni, and Fe in snow exceeded their contents in river waters. The HM and Fe percentage in suspended form in river water and different snow states is calculated and the sequence series are constructed. The analysis showed that in melt-water, in comparison with river water, there is a higher percentage of the HM and iron in the solution. That may be due to the slightly acidic reaction of the snow water medium, which, as is known, promotes the HM and Fe mobilization from the suspension and their transition to the dissolved state. Using electron microscopy and X-ray phase analysis, the suspension composition in the snow of the park zone was studied, which is mainly represented by aggregates of clay minerals, quartz grains, water silicates, feldspars, and organic matter clumps