Irina S. Ivanova

Peatlands are a major source of dissolved organic carbon (DOC) for inland waters in Western Siberia. Continuous hydrological and hydrochemical monitoring of these peatlands is essential for understanding the global carbon cycle. We investigated a pristine ombrotrophic bog in Western Siberia to determine the links between seasonal hydrological changes and DOC quantity and quality. Specifically, we analysed water table fluctuations, DOC concentrations and spectral characteristics (SUVA ₂₅₄ , E2:E3 and E4:E6 ratios). Our findings indicate that each peatland ecosystem exhibits distinct seasonal hydrochemical changes. The driest ecosystems (ryams) feature water with the highest DOC concentrations, characterised by high aromaticity and large molecular size, whereas the wettest ecosystems (pools) display the opposite trend. Surprisingly, the stream, which collects water from the entire peatland catchment, exhibits unique properties in that its DOC concentration is similar to that of wet ecosystems, while its spectral features more closely resemble those of dry ecosystems. Therefore, peatland ecosystems act as complex biogeochemical systems, modulating both the concentration and quality of dissolved organic carbon (DOC) based on prevailing environmental conditions.

Relevance. The study of isotopic composition of water and dissolved substances makes it possible to determine not only their genesis, but also the fractionation processes occurring in the “water–rock–gas–organic matter” system over time, i. e. as different stages of the evolution of water composition pass through. Interest in the groundwater of the Arctic regions of Western Siberia is additionally associated with the widespread occurrence of oil deposits at the depths of formation waters and the possible influence of cryogenic metamorphization processes on composition of near-surface waters. Aim. To study and compare the isotopic composition of oxygen, hydrogen and carbon in natural waters of the Yamalo-Nenets autonomous region to identify conditional isotopic markers, as well as to be able to trace the evolution of the isotopic composition of waters along a vertical section in the area of the Taz oil and gas condensate field. Objects. Surface (river, soil and lake), underground waters of the active water exchange zone of the Yamalo-Nenets autonomous region and formation waters of oil and gas deposits of the Taz field. Methods. The study of the isotopic composition of oxygen, hydrogen, and carbon of water-dissolved carbon dioxide was carried out in the Research Equipment Sharing Center at the Institute of Geology and Mineralogy SB RAS using Isotope Ratio Mass Spectrometer FinniganTM MAT 253 equipped with H/Device and GasBench II for sample preparation. Results and conclusions. The paper introduces the data on isotopic composition of O, H and C for natural waters of the Yamalo-Nenets autonomous region. The authors have determined the characteristic trends in changes in the isotopic composition of water and dissolved carbon dioxide for various water bodies. Surface and underground waters with active water exchange in terms of isotopic composition (δD and δ18О) are infiltration. As water moves down the section, with an increase in the time of interaction of the “water–rock” system and increase in temperatures, the isotopic composition becomes significantly heavier with a slope from the GMWL to the right. The authors compiled the diagram of the evolution of water-dissolved carbon isotopic composition in the region according to the obtained and some literature data. Despite the wide range of δ13C values from –30.4 to 23.6 ‰, there are, obviously, only two sources of carbon dioxide in the region: biogenic and atmospheric, with biogenic being predominant for groundwater. Актуальность. Исследование изотопного состава воды и растворенных веществ позволяет определить не только их генезис, но и процессы фракционирования, происходящие в системе «вода–порода–газ–органическое вещество» с течением времени, т. е. по мере прохождения различных этапов эволюции состава вод. Интерес к подземным водам арктических регионов Западной Сибири дополнительно связан с широким распространением здесь на глубинах пластовых вод нефтяных отложений и возможным влиянием на состав приповерхностных вод процессов криогенной метаморфизации. Цель: изучить и сопоставить изотопный состав кислорода, водорода и углерода в природных водах Ямало-Ненецкого автономного округа для выделения условных изотопных маркеров, а также для возможности проследить эволюцию изотопного состава вод вдоль вертикального разреза в районе Тазовского нефтегазоконденсатного месторождения. Объекты: поверхностные (речные, почвенные и озерные), подземные воды зоны активного водообмена Ямало-Ненецкого автономного округа и пластовые воды нефтегазоносных отложений Тазовского месторождения. Методы. Исследование изотопного состава кислорода, водорода вод, а также углерода водорастворенной углекислоты проводилось в ЦКП Многоэлементных и изотопных исследований СО РАН (г. Новосибирск) с помощью прибора Isotope Ratio Mass Spectrometer FinniganTM MAT 253, снабженного приставками пробоподготовки H/Device и GasBench II. Результаты и выводы. Приведены данные по изотопному составу кислорода, водорода и водорастворенного углерода для природных вод Ямало-Ненецкого автономного округа. Определены характерные тренды изменения изотопного состава вод и растворенной углекислоты для различных водных объектов. Показано, что поверхностные и подземные воды активного водообмена по изотопному составу (δD и δ18О) являются инфильтрационными. По мере движения вод вниз по разрезу, с увеличением времени взаимодействия в...

Data on the content of fluorine and components of the main salt composition in surface and ground waters of the Yamalo-Nenets Autonomous Okrug, sampled in September 2021, are presented. River waters contain 0,022–0,094 mg/L of fluorine with the lowest concentrations characteristic of small rivers and the highest – for large ones, such as the Nadym River (0,046 mg/L) and the Ob River (0,094 mg/L). Fluorine concentrations in artesian groundwater used for water supply are generally higher and range from 0,056 to 0,269 mg/L. In both river and ground waters of the area, the fluorine content is much lower than the sanitary-hygienic optimum, amounting to 0,7–1,5 mg/L.

Ссылка для цитирования: Лепокурова О.Е., Иванова И.С., Пыряев А.Н. Использование стабильных изотопов водорода, кислорода и углерода при интерпретации условий формирования поверхностных водных объектов Ямало-Ненецкого автономного округа // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2023. – Т. 334. – № 6. – С.7-19. Актуальность. Стабильные изотопы широко используются в геохимии при решении различных генетических задач, что связано с допущением о постоянстве первозданного изотопного состава любого элемента, впоследствии измененного под воздействием различных процессов. В практике исследований поверхностных вод изотопные методы применяются при решении не только прямых генетических, но и различных сопутствующих приложений. В арктических регионах, подверженных влиянию многолетней мерзлоты, изотопы воды все чаще используются для оценки вклада талых вод в баланс общего речного стока, особенно в условиях ускорения темпов таяния, что ведет к изменению гидрологического режима и общей структуры ландшафта. Анализ изотопного состава водорастворенного углерода представляет отдельный исследовательский интерес, поскольку дает представление об участии высвобождаемого при таянии мерзлотных торфов органического вещества в изотопном обмене с водами. Совместное использование химических и изотопных характеристик водных объектов позволит детально изучить генезис, особенности формирования и взаимодействия данных вод с окружающей средой. Цель: уточнение генезиса и условий формирования поверхностных водных объектов арктических районов Западной Сибири, подверженных влиянию многолетней мерзлоты, с использованием состава стабильных изотопов Н, О, С. Объекты: поверхностные водные объекты тундровой и лесотундровой природных зон Ямало-Ненецкого автономного округа. Полевые исследования проходили в августе 2020 г. Пробы воды на изотопный состав были отобраны в трех крупных реках – Обь, Таз, Пур, и в правом притоке реки Пур – Нгарка-Хадытаяха, в 7 крупных озерах (площадью от 2,5 тыс. до 300 тыс. м2) и в 1 мелком термокарстовом озере (12 м2), в 3 просадках (начальная стадия образования термокарстовых озер) и 2 почвенных разрезах. Всего 17 проб воды. Кроме того, были отобраны 5 образцов торфа на одном почвенном разрезе в пяти интервалах по глубине до 55 см. Методы. Химический состав вод был проанализирован в аккредитованной Проблемной научно-исследовательской лаборатории гидрогеохимии Томского политехнического университета методами титрования, масс-спектрометрии с индуктивно-связанной плазмой, фотометрии, ионной хроматографии и высокотемпературного каталитического окисления. Исследование изотопного состава кислорода, водорода вод, а также углерода водорастворенной углекислоты проводилось в Центре коллективного пользования многоэлементных и изотопных исследований СО РАН с помощью прибора Isotope Ratio Mass Spectrometer FinniganTM MAT 253, снабженного приставками пробоподготовки H/Device и GasBench II. Результаты. Приведены данные по изотопному составу кислорода и водорода вод, а также водорастворенного углерода для поверхностных вод тундровой и лесотундровой природных зон ЯНАО. Показано, что для каждого объекта (почв, просадок, озер и рек) характерны индивидуальные интервалы значений δD, δ18О, δ13С (водорастворенный углерод), что указывает...

Climate change is likely to modify the freezing–thawing cycles in soils and surface waters of permafrost-affected and subarctic regions. However, the change of solution chemical composition during ice formation and the evolution of the remaining fluids remain very poorly known. Towards a better understanding of dissolved (<0.45 µm) organic carbon, as well as major and trace element behavior in permafrost peatland environments, here we performed laboratory freezing of peat leachates, from complete freezing to complete thawing, in order to quantify the partitioning of solutes between the aqueous solution and the remaining ice. Freezing experiments were conducted, with and without polyurethane insulation. Two main types of experiments involved (i) progressive freezing, when we started from liquid leachates (filtered <0.45 µm) and allowed them to freeze at −18 °C, and (ii) progressive thawing, where first, we froze solid a series of <0.45 µm filtered leachates and then monitored their thawing at room temperature, 20 °C. We hypothesized the existence of two main groups of solutes, behaving conservatively or non-conservatively during freezing, depending on their incorporation into the ice or their ability to coagulate in the form of insoluble minerals or amorphous materials in the fluid phase. An unexpected result of this work was that, despite a sizable degree of element concentration in the remaining fluid and possible coagulation of organic, organo-mineral, and inorganic compounds, the freezing and subsequent thawing produced final concentrations of most solutes which were not drastically different from the initial concentrations in the original leachates prior to freezing. This demonstrates the high stability of dissolved (<0.45 µm) organic carbon, iron, aluminum, and some trace metals to the repetitive freezing and thawing of surface waters in permafrost peatlands.

Link for citation: Volkova N.A., Ivanova I.S., Sokolov D.S., Kolubaeva Yu. V., Chuikina D.I. Concentrations and sources of polycyclic aromatic hydrocarbons in water and sediments of rivers of northern oil and gas producing territories of Western Siberia. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 4, рр.135-148. In Rus. The relevance. Huge reserves of both fresh water and hydrocarbons are concentrated on the territory of Western Siberia, the extraction and development of which is increasing every year. Oil is one of the main environmental risk factors for the natural ecosystems of the North. Among the components of oil, polycyclic aromatic hydrocarbons stand out, which have carcinogenic and mutagenic properties and have a negative impact on natural ecosystems. However, there are quite a lot of sources of these organic pollutants entering the environment, including they can be of both natural and anthropogenic origin. The relevance of the study of the content and composition of these components is caused not only by their toxicity, but also by their resistance to chemical and biological transformation, high migration activity and ability to accumulate in natural environments. The aim of this work was to study the individual composition and distribution of polycyclic aromatic hydrocarbons in water and bottom sediments of rivers, and to identify possible sources of polycyclic aromatic hydrocarbons entering water bodies of the Arctic zone of Western Siberia. Objects: river waters and bottom sediments taken from 8 watercourses in the territory of the Yamalo-Nenets Autonomous Okrug. The objects were chosen in such a way as to cover rivers of various orders within the catchment basins of the main rivers of the Yamalo-Nenets Autonomous Okrug. Methods. The content and individual composition of polycyclic aromatic hydrocarbons in water and bottom sediments of rivers was determined in the laboratory of physical and chemical studies of core and reservoir fluids of the Trofimuk Institute of Petroleum Geology and Geophysics SB RAS (Tomsk) using high-performance liquid chromatography. Statistical processing of the obtained data was carried out using the Microsoft Office Excel and PAST V2.17 software packages. Results. The features of the distribution of polycyclic aromatic hydrocarbons in water and bottom sediments of the rivers of the northern territories of Western Siberia have been studied. The total content of polycyclic aromatic hydrocarbons in the river waters of the YaNAO varies from 292,8 to 1098,0 ng/l. The minimum content of polycyclic aromatic hydrocarbons, represented mainly by low molecular weight compounds (mainly phenanthrene), associated with terrestrial higher vegetation, was established in the Mahanyad-Pusyakha River, which is a tributary of the Nadym River. The highest concentration of the studied compounds, represented mainly by high molecular weight polycyclic aromatic hydrocarbons, was identified in the water of the Apoku-yakha River, tested near the developed deposits and related to the catchment area of ​​the Pur River. The sources of identified compounds in this sample can be associated with both petrogenic and pyrogenic processes. The total content of polycyclic aromatic hydrocarbons in bottom sediments varies from 1900 to 20000 µg/kg, which is due to the presence of not only natural, but also anthropogenic pollution. The maximum concentration of these compounds was found in the bottom sediments of the Apoku-yakha River. Using statistical analysis, indices diagnosing polycyclic aromatic hydrocarbon sources were established: for water – ratios Flt/Pyr and (Pyr+BaP)/(Chr+Phen), for bottom sediments – ratios BaA/(BaA+Chr), Phen/(Phen+Chr ) and (Pyr+BaP)/(Chr+Phen).On the basis of the data obtained, it was found that polycyclic aromatic hydrocarbons enter the rivers, as a rule, from natural sources. The probable sources of polycyclic aromatic hydrocarbons entering bottom sediments can be divided into several groups: oil burning, combustion processes, as well as mixed sources. Polycyclic aromatic hydrocarbons identified in water and bottom sediments of the Apoku-yaha River have an anthropogenic genesis. The environmental assessment of the state of the rivers, based on the calculation of the polycyclic aromatic hydrocarbon hazard coefficient and the bottom accumulation coefficient, indicates a high level of chronic pollution of the studied objects. It was established that the most intense pollution is characteristic of the rivers belonging to the catchment area of the Pur River, where the most active hydrocarbon production takes place. Ссылка для цитирования: Концентрации и источники полициклических ароматических углеводородов в воде и донных отложениях рек северных нефтегазодобывающих территорий Западной Сибири / Н.А. Волкова, И.С. Иванова, Д.А. Соколов, Ю.В. Колубаева, Д.И. Чуйкина // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2023. – Т. 334. – № 4. – С.135-148. Актуальность. На территории Западной Сибири сосредоточены огромные запасы как пресных вод, так и углеводородов, добыча и разработка которых увеличивается с каждым годом. Нефть является одним из главных факторов экологического риска для природных экосистем Севера. Среди компонентов нефти выделяются полициклические ароматические углеводороды, обладающие...

The climate change is likely to modify the freezing-thawing cycles in soils and surface waters of permafrost-affected and subarctic regions. Yet, the change of solution chemical composition during ice formation and evolution of remaining fluids remain very poorly known. Towards better understanding of dissolved (< 0.45 µm) organic carbon, major and trace elements behavior in permafrost peatland environments, here we performed laboratory freezing of peat leachates, from complete freezing to complete thawing in order to quantify the partitioning of solutes between the aqueous solution and the remaining ice. We hypothesized the existence of two main groups of solutes, behaving conservatively or non-conservatively during freezing depending on their incorporation into the ice or ability to coagulate in the form of insoluble minerals or amorphous materials in the fluid phase. An unexpected result of this work was that, despite sizable degree of element concentration in the remaining fluid and possible coagulation of organic, organo-mineral and inorganic compounds, the freezing and subsequent thawing produced the final concentrations of most solutes which were not drastically different from initial concentrations in starting leachates, prior freezing. This demonstrates high stability of dissolved (< 0.45 µm) OC, Fe, Al and some trace metals to repetitive freezing and thawing of surface waters in permafrost peatlands.

An Erratum to this paper has been published: https://doi.org/10.1134/S0016702922190016

The content and composition of 19 priority polycyclic aromatic hydrocarbons (PAHs) in peat oligotrophic soils (Cryic Histosols) in the northern territories of Western Siberia were analyzed by gas chromatography in chloroform extracts. The content of PAHs in the examined soils varies from 33 to 148 ng/g. Low molecular weight (three-ring) PAHs account for 70–75% of the PAHs composition, while the total share of high molecular weight compounds does not exceed 25%. The latter are mainly represented by four-ring species, their concentrations decreasing in the sequence: fluoranthene > pyrene > chrysene. Cluster analysis (Euclidean index and pair group method) demonstrates the correlation of PAH composition with residual eutrophication and manifestation of soil degradation signs. Principal component analysis shows that phenanthrene, pyrene, and, to a lesser degree, fluoranthene and anthracene display the strongest positive correlation with the first component. The second component correlates with the contents of fluoranthene, fluorene, and naphthalene. The degradation of soil oligotrophic peat horizons accompanied by the appearance of mucky material appears as a decrease in the share of fluoranthene and an increase in the concentration of naphthalene. In oligotrophic peat horizons with the signs of residual eutrophication, the share of fluorene and naphthalene increases along with a decrease in the content of phenanthrene and fluoranthene. The diagnostic ratios identified by principal component analysis—Ant/(Ant + Phe) and Flt/Pyr—suggest a natural (petrogenic) origin of the PAHs in all examined peat soils.