Semenkov L.N., Sharapova A.V., Lednev S.А., Koroleva Т.V. FRACTIONATION OF METALS AND S IN THE TOPSOILS EFFECTED BY A COAL WASTE HEAP (CENTRAL RUSSIAN FOREST-STEPPE) // Arid Ecosystems. 2023. Vol. 29. № 2 (95). P. 118-127. | PDF
The non-reclaimed coal waste heap of the Moscow Coal Basin represent a long-term spontaneous experiment that reflects the transformation of soils under the influence of the acid mine drainage enriched with potentially toxic heavy metals and metalloids. In the Tula region, to analyze the fractionation of macro elements in the soils effected by acid sulfate water, at 11 points (a total of 57 samples), we studied electrical conductivity of the water extract, the granulometric composition, pH, the concentration of total organic carbon and the three mobile fractions (exchangeable, complexed, and specifically sorbed), as well as the total content of Al, Ca, Fe, Mn, and S. Technosols of a waste heap with a predominantly very acidic medium often have sulfate salinity. Acid sulfate water and solid-phase matter from the waste heap form deluvial-proluvial sheets, which bury highly productive Chernozems and Phaeozems. In terms of the fractional-group composition of Al, Ca, Fe, Mn, and S, bared Regosols (Phytotoxic) at the sheets are close to the toxic substrates of the waste heap, and plant-covered Regosols are close to the background Chernozems. In comparing with the waste heap material, in the transported material of bared Regosols (Phytotoxic) at deluvial-proluvial sheets, the content of mobile compounds and the total content of Ca and S reduces. In in the transported material of plant-covered Regosols, the content of Mn mobile compounds and the mobility of Al increases and the mobility of Fe decreases. The input of acid sulfate water into the A-horizon of Chernozems increases the content of mobile compounds and the total content of S and water-soluble Ca2+ and decreases the content of mobile compounds and the total content of Mn. The mobility of macro elements decreases in the raws Ca > Fe > S, Mn, Al; Ca > Fe, Mn > S, Al and Mn > Ca > Fe, Al > S in the most toxic material, in the transported material of plant-covered Regosols and in the buried A-horizon of Chernozem, respectively.
Keywords: potentially toxic elements; black soils; Chernozems, Technosols, partition, fractionation; acid mine drainage.
Acknowledgement. The authors are grateful to P.P. Krechetov for discussing the interim results of the study, B.A. Ibragimova for assistance in performing quantitative chemical analysis, E.S. Starchikova and N.A. Yudina for sample preparation and preparation of aqueous extract, L.V. Dobryneva (M.V. Lomonosov Moscow State University) for chromatographic analysis of aqueous extract, A.I. Yakushev (Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry of RAS) for gross analysis, V.K. Karandashev (Institute for Problems of Technology of Microelectronics and High-Purity Materials of RAS) for the elemental analysis of hoods. Materials provided by the Center for Collective Use “Geoportal” (M.V. Lomonosov Moscow State University) were used in the selection of research objects.
Financing. The research was carried out for the Russian Foundation for Basic Research project No. 20-35-70066 (field and chemical-analytical work) and supported by the Interdisciplinary Scientific and Educational School of Lomonosov Moscow State University “The Future of the Planet and Global Environmental Changes” (interpretation of the results).