Biochemical transformation of petroleum hydrocarbons in the waters of western Siberia

About the authors:

Larisa P. Panicheva, Dr. Chem. Sci., Professor, Department of Organic and Ecology Chemistry, Institute of Mathematics, Natural Sciences and Information Technologies, Tyumen
State University

Tatyana I. Moiseyenko, Dr. Sci. (Biol.), Professor, Corresponding Member of the RAS, Deputy Director for Science, Vernadsky Institute of Geochemistry and Analytical Chemistry of the RAS (Moscow); moiseenko.ti@gmail.com

Tatyana A. Kremleva, Dr. Sci. (Chem.), Professor, Department of Organic and Ecological Chemistry, University of Tyumen; t.a.kremleva@utmn.ru

Svetlana S. Volkova, Chief engineer, Department of Organic and Ecology Chemistry, Institute of Mathematics, Natural Sciences and Information Technologies, Tyumen State University

Abstract:

Study of biochemical transformation of petroleum hydrocarbons and nitrates in the waters of 127 lakes, (from the tundra to the forest-steppe zone) effect in the territory of Western Siberia (WS). The main anthropogenic sources of pollution by oil products and nitrates are the exploitation of oil and gas exploration and gas flaring. For most of the lakes in WS, quite distant from the sources of anthropogenic pollution self-purification capacity water reservoirs during the summer reduces petroleum hydrocarbons and nitrate content to below the maximum permissible concentration (MPC) for the fishery reservoirs. This significantly increases the organic carbon (Corg) and organic nitrogen (Norg). For natural zones of the WS median Corg ranges from 4.38 to 26.6 mg/dm3, Norg — from 0.17 to 1.52 mg/dm3. Biochemical transformation of petroleum products includes anaerobic process of humification and aerobic process of mineralization. In the lakes of the northern and middle latitudes of the WS (above 58o latitude) humification is 80%, mineralization — 20%, in the lakes of the southern latitudes of the WS (below 58o latitude) humification — 30%, mineralization — 70%. Anaerobic oxidation of hydrocarbons and organic remains followed by recovery of nitrate to nitrite and ammonium. Amination of the intermediate products of oxidation of organic compounds leads to increased levels of organic nitrogen and humic substances. In natural areas the range of the northern and middle latitudes (tundra, forest tundra and northern taiga, middle taiga) in the waters of lakes has a significant amount of ammonium, which determines the process of humification dominance over the process of mineralization of organic matter. In natural areas range of southern latitudes (southern taiga, foreststeppe) humification process is limited almost total depletion of ammonium. The molar ratio of carbon and nitrogen in aquatic humic substances: C: N = 23,4: 1.

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