METAL MIGRATION FORMS IN THE WATERS OF THE UNZHA RIVER BASIN (UPPER VOLGA REGION)
I.N. Ovchinnikova1, A.P. Sizov2
1All-Russian Research Institute of Environmental Protection, Moscow, Russia
2Moscow State University of Geodesy and Cartography, Moscow, Russia
Keywords: heavy metals, humic acids, hydrosphere, environment, landscapes, southern taiga
Abstract
The differentiation of the elements according to the phase composition of natural waters, which reliably characterizes the geoecological situation in the region of the Unzha river basin (the left tributary of the Volga river), the basicity of soil-geochemical processes and associated flows of matter and energy in soils and landscapes, was studied. Studies were carried out in key areas of landscapes in the middle and lower reaches of the river valley (35 soil sections were established). It is found that the natural waters of the Unzha basin constitute a complex multicomponent system where the ion composition of the waters and the reaction of the medium vary over a broad range according to their lithogenic component and water category. Migration of Fe, Mn, Zn and Cu in soil-ground waters of the Unzha basin proceeds mainly in suspended material, and in the dissolved phase in the waters of brooks, rivers and wells. In the waters of brooks and rivers, the total amount of suspended material is smaller than in soil-ground water; therefore, its role in the transfer of Fe, Mn, Zn and Cu is reduced accordingly. Migration of these elements increases in the composition of soluble humic acids, mainly fulvic acids. The role of dissolved humic acids, largely fulvic acids, in the transfer of Fe, Mn, Zn and Cu averages 28 %, 10, 41.9 and 33.7 %, respectively. Along with fulvic acids, the role of humic acids in the removal of these elements increases in bogs rich in organic matter. In the waters of the Unzha river, its tributaries and brooks, the coefficient of water migration КхFe = 0.4, which is an order of magnitude higher than the corresponding value according to Perelman’s classification. In the soil-ground water, Fe migration increases further: КхFe = 0.5. According to the intensity of water migration in the landscapes of the Unzha river, the elements are arranged in the following decreasing sequence: Zn ≥ Cu ≥ Mn ≥ Fe. A marked increase in the mobility of elements occurs in the acidic environment of the bog waters (pH 3.7-4.1), rich in dissolved organic matter.
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