Mercury In Bottom Sediments Research Articles

Distribution of mercury in lakes of different landscape zones in the south of Western Siberia using the example of model objects along a meridional transect

The work presents data on the concentration of mercury in bottom sediments of lakes, which are characterized by the nival type of sedimentogenesis. The mercury content for bottom sediments of lakes sampled in the middle and high mountains of the Altai Mountains is on average 0.06 μg/g. Differences in mercury concentration values for high- and mid-mountain lakes have not been established. It has been established that, regardless of the type of sedimentogenesis in lakes of different landscape zones of the south of Western Siberia along the meridional transect, the distribution of mercury along the section is characterized by an increase in values up the section towards the bottom sediments-water boundary, where they reach maximum values.

Ecological risk of mercury in bottom sediments and spatial correlation with land use in Neotropical savanna floodplain lakes, Araguaia River, Central Brazil

The Araguaia River floodplain is an important biogeographic boundary between the two largest South American biomes: the Cerrado (Brazilian Savanna) and the Amazon rainforest. The large-scale degradation due to land use conversion experienced in the Araguaia River watershed represents a potential source of mercury (Hg) transport to aquatic ecosystems. However, more information is needed about the dynamics of Hg distribution in savanna floodplains, including the Araguaia River floodplain. We analyzed total mercury (THg) concentrations in the bottom sediments of 30 lakes connected to the Araguaia River and four tributaries, aiming to evaluate the environment's integrity based on the geoaccumulation index (Igeo) and the ecological risk index (ERI). The principal component analysis was applied to examine associations between Hg concentrations, environmental conditions, and land use intensity among lakes associated with different river systems. We used indicator cokriging to identify areas with a greater probability of Hg pollution and ecological risk associated with land use intensity. The land use data showed the predominance of areas used for pasture in the Araguaia River basin. THg concentrations in the sediments varied between 22.6 and 81.9 ng g−1 (mean: 46.5 ± 17.7 ng g−1). Sediments showed no significant pollution (Igeo: 1.35 - 0.50; Classes 1 and 2) and low to considerable ecological risks (ERI: 23.5–85.1; Classes 1 to 3). THg in bottom sediments was associated with land use, water turbidity and electrical conductivity, and sediment organic matter. The indicator cokriging indicates a moderate to strong spatial dependence between land use intensity and Hg, confirming the contribution of anthropic sources to the increment of ecological risk but also the influence of extrinsic factors (such as environmental conditions, geology, and hydrology). Integrating sediment assessment and land use indices with geostatistical methods proved a valuable tool for identifying priority areas for Hg accumulation at a regional scale.

Mercury in bottom sediments of Russian Arctic lakes

Abstract. This article presents the results of studying the distribution of mercury in the cores of bottom sediments of both background and technogenic Arctic lakes in three regions: the Kola North, Malozemelskaya tundra and northwest Siberia. For all cores, the elemental composition, granulometry, and loss on ignition (LOI) were determined layer by layer. Mercury showed a significant excess of the local background in the near-surface sedimentary layers of most lakes. Fluxes of mercury from the pre-industrial period to the present were calculated. We discuss the possibility of technogenic pollution due to transboundary transfer.

Mercury and other heavy metals in the bottom sediments of Lake Loshamye (national park “Smolensk Lakeland”)

In 2008–2010, monitoring work in the national park «Smolensk Lakeland» showed an excess of mercury in the water of Lake Loshamye located in the protected area of the natural reserve. In 2014–2019, together with the staff of the national park, we studied the ecological and geochemical features of the catchment area and the water area of Lake Loshamye. We studied the patterns of distribution of several heavy metals: Hg, Cr, Mn, Fe, Co, Cu, Zn, As, Cd, Pb, Sr. We did not find an anthropogenic influence on the catchment area; this article presents the results of the study of the bottom sediments of the lake. As a result of the work, we determined that all heavy metals have a natural distribution in this lake, except mercury. High values of mercury in bottom sediments (up to 1000 ppb) are not typical for such natural object. The median of the sample is 152 ppb, and it is four times higher than expected mercury content considering its content in the soils of the catchment area and 2–5 times higher than the values obtained for similar objects by other researchers. The analysis of the patterns of mercury distribution in bottom sediments indicates a one-time, local anthropogenic pollution of the lake.

ВЛИЯНИЕ ПРИРОДНЫХ ФАКТОРОВ НА СОДЕРЖАНИЕ РТУТИ В ОЗЕРАХ СЕВЕРА ЗАПАДНОЙ СИБИРИ

Актуальность исследования обусловлена тем, что ртуть участвует в глобальном планетарном биогеохимическом цикле и входит в пищевые цепи с накоплением в организмах хищных видов животных и у коренного населения. В отношении к территории Западной Сибири информация о содержании ртути в озерах не достаточно полная, а обобщения сделаны на малых выборках, что делает актуальным фоновые изучения содержания ртути в среднетаежных озерах на репрезентативной выборке. Целью исследования является анализ и обобщение фоновых мониторинговых наблюдений, как за общим содержанием ртути донных отложений, так и её содержанием в поверхностных водах озер, в зависимости от природных факторов в условиях средней тайги в пределах Ханты-Мансийского автономного округа. Объект: фоновая концентрация растворенной Hg и ртути в донных отложениях озер. Изучено 95 озер, 322 пробы донных отложений, отобранных в разное время. Методы: атомно-адсорбционная спектрометрия (метод «холодного пара») определения ртути в аккредитованных лабораториях в соответствии с методическими рекомендациями. Использованы данные фонового экологического мониторинга с 2007 по 2011 гг. Результаты. Средняя фоновая концентрация ртути в донных отложениях составляет 0,046±0,012 мг/кг, растворенной ртути – 0,025±0,014 мг/кг. Наибольшая концентрация Hg выявлена в элювиальной и трансэлювиальной позициях, наименьшая – в супераквальных ландшафтах. Концентрация Hg имеет максимальное значение в озерково-грядово-мочажинном комплексе торфяных болот, а самое низкое – в донных отложениях озер на минеральных почвах. Наблюдается тенденция увеличения концентрации ртути в донных отложениях озер от зоны тундры, северной тайги до подзоны средней тайги. Но нарастает заболоченность территорий с юга на север, что способствует увеличению содержания ртути в донных отложениях озер (R=0,4). Отмечается увеличение растворенной ртути в озерах с запада на восток (по долготе) (R=0,6). Оценка динамики изменения содержания ртути в донных отложениях позволяет заключить, что в зимний период содержание ртути выше по сравнению с летним периодом. Концентрация растворенной ртути возрастает с запада на восток, но ртуть донных отложений этой закономерности не соответствует.

Total mercury in surficial bottom sediments of Volga River’s reservoirs in Central Russia

The total mercury content of the surface layer (0–5 cm) of different types of bottom sediment in Gorky and Cheboksary reservoirs was determined. The content of mercury in bottom sediments varied within a wide range, 0.001–0.234 mg/kg. In spite of large industrial enterprises near the watersheds, which are potential sources of mercury in the environment, the content is comparable to background values. Depending on the sediment type, the metal concentration rises within a sequence: sand and loamy sand > sandy loams > clay and silt. The content of mercury positively correlates with the amount of organic matter in bottom sediments (r = 0.49–0.86, p ≤ 0.001) and the proportion of clay silt particles (r = 0.55–0.76, p ≤ 0.001). This relationship indicates the presence of two forms of mercury: sorbed on fine particle surfaces and as part of complex compounds. A negative correlation between Hg concentration and the flow velocity in the reservoir was revealed (r = − 0.40 to − 0.58, p ≤ 0.05). This relationship is due to the effect of pulsating discharge and wind currents on sedimentation conditions, and thus on the accumulation of mercury. The rate of accumulation was calculated as 15 kg/year in Gorky reservoir and 9 kg/year in Cheboksary, with average concentrations of 0.057 and 0.046 mg/kg, respectively, in the surface layer of bottom sediments.

Long-term dynamics of total mercury in surficial bottom sediments of the Volga River's reservoir in central Russia.

The long-term dynamics of mercury in bottom sediments of Uglich Reservoir were examined. Samples of the 0-5-cm surface layer of bottom sediment collected during research expeditions in 1958, 1977, 1991, and 2012 were analyzed. An increase in the average mercury concentration from 1958 to 1977 (0.440 ± 0.039 and 0.668 ± 0.065mg/kg d.w., respectively) was followed by a decrease in 2012 (0.260 ± 0.021mg/kg d.w.). During all years except 1991, a significant correlation was found between mercury content and the amount of organic matter in the sediments (r = 0.54-0.87, p < 0.01), flow velocity (r = 0.38-0.53, p < 0.01), and the rate of sedimentation in the reservoir (r = - 0.51 to - 0.69, p < 0.01). Calculations based on these results and previously published data from the study region on the density of atmospheric mercury precipitation showed that the watershed as a whole received 2.4-3.0t on an annual basis, and in the same period, the water surface received 9.7-12.8kg of mercury. The bottom sediment contained 4.31 (2012)-7.40 (1977) tons of mercury. Thus, most of the mercury in the Uglich Reservoir is assumed to originate from runoff and terrigenous sources within the watershed.

Geochemistry of mercury in surface sediments of the Kuril Basin of the Sea of Okhotsk, Kuril-Kamchatka Trench and adjacent abyssal plain and northwest part of the Bering Sea

Mercury concentrations in surface sediments collected from the Northwestern Pacific were analyzed by mercury Zeeman atomic absorption spectrometer with high frequency modulation of light polarization and a pyrolysis attachment. The range of total Hg concentrations in sediments was 19–158µgkg−1, with a mean of 77µgkg−1 (n = 50). The variation in mercury concentrations in sandy deposits of the slopes was 19–79µgkg−1 Hg; in clayey deposits from the Kuril Basin was 84–130µgkg−1 Hg; in clayey deposits from slopes of the Kuril Basin was 44–84µgkg−1 Hg; in clayey deposits from the abyssal area was 46–116µgkg−1 Hg; and in clayey deposits from the slopes and bottom of the Kuril-Kamchatka Trench was 42–143µgkg−1 Hg.Within the distribution of mercury across the study area, high mercury concentrations were observed in clayey sediments, which are enriched in organic matter and the remains of silicate phytoplankton. The Hg content of sandy deposits was minimal. The level of mercury in our deep-water sediments is somewhat overestimated by comparison to representative background values in clayey sediments from the impact areas (subject to anthropogenic pollution). Anomalies of mercury in bottom sediments near a hydrothermal source (Piip Volcano) have not been observed. The enrichment factor values at the stations range between 0.3 and 4.3. EF values of the most samples were generally more than 1, indicating that enrichment was by biogeochemical processes. Based upon four guideline values (ERL, ERM, ISQG and PEL) we can assume a minimal toxic mercury effect on the benthic marine biota.

Particular Qualities of Migration and Concentration of Mercury in Bottom Sediments Near Industrial Territories

Particular Qualities of Migration and Concentration of Mercury in Bottom Sediments Near Industrial Territories

Mercury contamination of bottom sediments in water reservoirs of southern Poland

The aim of this study was to assess the mercury concentration in bottom sediments, collected from eight reservoirs located in south-eastern Poland. A DMA-80 Mercury Analyser was used for the analysis of the concentration of mercury in bottom sediments. Concentration of mercury in sediments was between 0.01-0.18 mg∙kg −1 . The research results show that 13 samples are above the Polish Hg background level. Only 9 samples are below the background level. Generally, the sediments belonged to class I and II (unpolluted and moderately polluted sediments). The concentration of mercury in bottom sediments follows the order: Ryb- nik (highest) > Bagna Rzeszowskie > Rzeszow > Ozanna > Brzoza Stadnicka > Brzoza Krolewska > Gluchow > Narozniki (lowest). The low mercury content in sediments is related to absent or limited anthropogenic sources of this metal. Elevated concentrations of Hg in bottom sediments of the reservoirs in Rybnik and Bagna Rzeszow- skie are related to their proximity to large agglomerations and industrial plants. Organic matter was likely to be the most important factors controlling the concentration and distribution of mercury in the studied sediments.

Mercury in bottom sediments of marginal seas of northeast Asia

The analysis of the concentrations and distribution of mercury in bottom sediments of marginal seas in northeastern Asia revealed that its maximum contents are characteristic of areas with an active geodynamic regime and some areas of the Amur Bay in the Sea of Japan subjected to anthropogenic impact. The geochemical associations of mercury with other chemical elements and its background concentrations in bottom sediments of these sea basins are defined.

Mercury in bottom sediments of the Amur River, its flood-plain lakes and estuary, Eastern Siberia

Mercury (Hg) is an element of a special concern in the Amur River basin, where numerous cinnabar deposits and manifestations have been prospected. Moreover, the territory is under heavy anthropogenic pressure due to intensive economic development that includes activities accompanied by noticeable emissions of Hg to the environment through poor waste management practices and accidental emergency discharges. Yet, information on Hg distribution and behavior in this region is scarce and inadequate. In order to evaluate Hg levels and fate in this vast territory, surveys of river, lake, and estuarine bottom sediments, as integral indicators of environmental status, were carried out in 1990, 1991, 1997, and 2004. The results showed the following: (1) stagnation of the Russian economy in the 1990s has resulted in a noticeable decrease of the Hg content in the Amur River sediments to the basin pristine level of about 0.05 mg kg(-1); (2) Hg distribution in the sediment depth proves the element redox-dependent behavior; (3) in some cases, Hg enrichment may be related to the long-term anthropogenic emission; (4) Hg concentration in bottom sediments was found to increase in the following order-the Amur River mouth, the estuary, and the Sea of Okhotsk, showing the weakly non-conservative Hg behavior during estuarine water mixing.

Mercury transformations in marine coastal sediments as derived from mercury concentration and speciation changes along source/sink transport pathway (Southern Baltic)

In this study the distribution of mercury in coastal marine sediments was investigated. Samples of surface sediments were collected from three areas in the southern Baltic. The Gdansk Basin was selected due to proximity to point sources, while the Arkona and the Bornholm Deeps – because they are distant from point sources. Both total concentration and solid speciation of mercury were measured. Sources, transport routes, and transformation of mercury in bottom sediments were assessed. Total concentrations varied in the range from 20 to 430 ng/g sediment d.w. The dominant forms of mercury were mercury sulphide (50% ± 10%), and mercury bound to both humins and mineral matrix (30% ± 20%). The Odra River seems to be the main source of mercury in the Arkona Deep, whereas diffuse sources contribute to the mercury in the sediments of the Bornholm Deep. In the Gdansk Basin, diversified sources seem to control the distribution of mercury. They include point pollution sources in the western part of the bay; the Vistula River – the main source of mercury in the central Gdansk Bay, its influence extending to the Gdansk Deep area. Sediments of the Gdansk Deep western slope receive mercury from the suspended matter of both the Vistula River and the currents from other coastal regions as well as aerial long-range transport. Mercury species undergo transformation in the course of transport to depositional basins – which leads to partial remobilization of mercury from the sediments.

Mercury in bottom sediments of the tropical Rio Marabasco, its estuary, and Laguna de Navidad, Mexico.

1 CEUNIVO, University of Colima, Manzanillo, Colima, Mexico 2 Institute of Water and Ecological Problems, Far Eastern Branch of Russian Academy of Sciences, 65, Kim Yu Chen Street, Khabarovsk, 680000, Russia 3 Interdisciplinary Marine Science Center, Av. IPN s/n, col. Playa Palo de Santa Rita, Apdo Postal 592, La Paz, Baja California Sur, 23096, Mexico 4 P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia

河川底質の水銀汚染について １ 水門川底質の水銀汚染

The wastewater of a chemical plant manufacturing acetaldehyde with mercurial catalyst had been emitted into the Suimon River in Gifu Prefecture. Monitoring surveys were made by measuring total mercury in bottom sediments from 124 sites in the Suimon River and the relevant rivers. The highest level, 180μg/g of mercury was detected at the site close to the outfall of the chemical plant and the mercury level ranged from the order of 10 to 102μg/g at the sites downstream, whereas they represented the order of 10-1to 100μg/g at the sites upstream. Therefore, the plant was proved to have been the source of mercury pollution of bottom sediments. The mercury pollution apperared to extend to the Makita River but not to the Ibi River. From the results of the survey of the horizontal distribution of mercury concentrations in sediments at 14 sites, it was found that the coefficient of variation of mercury concentrations in sediments from varied positions at a site reached 81.8% on the average, and mercury concentrations were generally lower in the centre of the channel but increased towards the shore. From the results of vertical distribution of mercury concentrations, a fairly regular relationship was obtained between depths of sampling positions and mercury concentrations. However, at some sites the relationship was observed to be inverse.