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.