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

Abstract

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.

Granulometric, elemental and isotopic composition of bottom sediments of lakes of mountainous areas as a reflection of transformations in their watersheds

“…We did not study the granulometric composition of E3S Web of Conferences 407, 02009 (2023) APEEM 2023 https://doi.org/10.1051/e3sconf/202340702009 the bottom sediments of Lake Abrau, so we used the information obtained only for the bottom sediments of Lake Malyy Liman. This is acceptable because, as shown in [4], both lakes were formed in similar geological and tectonic conditions and are attributed to a single natural-technogenic system.…”

“…2) is freshwater, although behind a thin bridge is the sea with a water salinity of about 18 g/dm3. The seawater does not enter the lake [4]. It was formed 5-7 thousand years ago due to a strong earthquake [6; 7].…”

“…An expedition was conducted to select columns of bottom sediments up to 95 cm deep in the lakes Malyy Liman and Abrau. Bottom sediments were collected using a bottomsampling device [4]. Their visual and microscopic description was made.…”

“…It should be noted that the amount of pelitic fractions is in inverse proportion to that of fine aleurite fractions. It is E3S Web of Conferences 407, 02009 (2023) APEEM 2023 https://doi.org/10.1051/e3sconf/202340702009 known [4] that the water regime of the lake is characterized by inconstancy, which led from almost complete desiccation of the reservoir to its overfilling. In dry years, when surface runoff and perched groundwater was a minimal, terrigenous material entered the lake basin.…”

“…Bottom sediments with a change in the physicochemical and hydrodynamic situation can act as a secondary source of pollution of the water column. One of the dominant factors controlling the distribution, accumulation, and dispersion of pollutants in water bodies is their particle size distribution and material composition [4]. In turn, it is formed under the influence of the entry into water bodies of products of destruction of rocks that make up their drainage basins.…”