Occurrence Forms of Heavy Metals in the Bottom Sediments of the White Sea

Author(s):  
Liudmila L. Demina ◽  
Dmitry F. Budko ◽  
Alexander N. Novigatsky ◽  
Tatiana N. Alexсeeva ◽  
Anastasia I. Kochenkova
Author(s):  
Alina Zimovets ◽  
Alina Zimovets ◽  
Yury Fedorov ◽  
Yury Fedorov ◽  
Asya Ovsepyan ◽  
...  

A study was conducted to investigate the level of heavy metals in bottom sediments of the Northern Dvina mouth area and the White Sea in various seasons since 2004. Of greatest interest for the study was presented as such heavy metals as Hg, Pb, Cd, Cu, Ni, Zn, Cr, which belong to the priority group of toxic elements. The heavy metals concentrations were determined with atomic absorption spectrometer. Also the grain-size composition, concentrations of organic carbon and values of hydrogen ion exponent (pH) and redox potential (Eh) in bottom sediments were determined. It was found that the levels of heavy metals in sediments significantly changed in the lateral radial direction. There is a tendency to increased concentrations of some heavy metals downstream of the river. The high concentrations of heavy metals were found within the influence of cities and towns. So the extremely high mercury concentrations were found in the sediments of small and shallow channels crossing the Arkhangelsk city. The study of heavy metal concentrations in the bottom sediments along the profile “the Northern Dvina - Dvina Bay - White sea” showed that the marginal filter contributes to the coprecipitation with suspended metals of anthropogenic genesis. These processes greatly reduce the contamination risk of the White Sea. Thus, the impact of the river on the ecosystem of the White Sea outside the marginal filter is significantly less.


Author(s):  
Alina Zimovets ◽  
Alina Zimovets ◽  
Yury Fedorov ◽  
Yury Fedorov ◽  
Asya Ovsepyan ◽  
...  

A study was conducted to investigate the level of heavy metals in bottom sediments of the Northern Dvina mouth area and the White Sea in various seasons since 2004. Of greatest interest for the study was presented as such heavy metals as Hg, Pb, Cd, Cu, Ni, Zn, Cr, which belong to the priority group of toxic elements. The heavy metals concentrations were determined with atomic absorption spectrometer. Also the grain-size composition, concentrations of organic carbon and values of hydrogen ion exponent (pH) and redox potential (Eh) in bottom sediments were determined. It was found that the levels of heavy metals in sediments significantly changed in the lateral radial direction. There is a tendency to increased concentrations of some heavy metals downstream of the river. The high concentrations of heavy metals were found within the influence of cities and towns. So the extremely high mercury concentrations were found in the sediments of small and shallow channels crossing the Arkhangelsk city. The study of heavy metal concentrations in the bottom sediments along the profile “the Northern Dvina - Dvina Bay - White sea” showed that the marginal filter contributes to the coprecipitation with suspended metals of anthropogenic genesis. These processes greatly reduce the contamination risk of the White Sea. Thus, the impact of the river on the ecosystem of the White Sea outside the marginal filter is significantly less.


Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 332
Author(s):  
Nadezhda Khaustova ◽  
Yulia Tikhomirova ◽  
Svetlana Korost ◽  
Elena Poludetkina ◽  
Andrey Voropaev ◽  
...  

To evaluate the effect of redox conditions at the sedimentation stage on uranium content and U/TOC ratio in marine source rocks, we analyzed the accumulation of uranium in modern marine bottom sediments formed in different redox conditions. The behavior of uranium from bottom sediments formed in oxidizing and sub-oxidizing settings has been studied on the sediments of the Upper Pleistocene–Holocene age accumulated in the coastal area of the White Sea (Kandalaksha Gulf). We studied the content of uranium, Eh, pH, TOC, C, H, N, and S element and isotope compositions and other parameters in two sampled columns of bottom sediments at a depth of 0–2.5 m. The composition of sediments was typical for the shelf zone where marine genesis mixes with the continental run-off. The upper layer of sediments (0–50 cm) were characterized by oxidizing conditions (Eh ~ 400 mV); with the increase in depth, redox conditions changed from oxidizing to reducing (0 ÷ 200 mV). The uranium concentration in the upper layer was 1–1.5 ppm, U/TOC ratio varied in the range of 0.8–1.1 ppmU/%TOC. The uranium content and U/TOC ratio increased up to the values of 2.6 ppm and 1.4 ppmU/%TOC at a depth of 0.5−2.5 m, respectively, but the general content of uranium in the studied environment was close to the values characterizing continental run-off. The results obtained for the White Sea sediments were compared with the sediment of the Black Sea, formed in the anoxic conditions of hydrogen sulfide contamination. In these conditions, the uranium content varied from 10 to 20 ppm. The obtained data were interpreted using thermodynamic modeling of the uranium forms in the seawater at different pH and Eh. This study demonstrated that the change of redox conditions from oxidizing to reducing leads to increased uranium content due to a decrease in uranium’s solubility in water. These results show that oxidation–reduction potential could be one of the most important factors controlling uranium content in black shales formed in the marine environment.


2006 ◽  
Vol 406 (1) ◽  
pp. 136-140 ◽  
Author(s):  
G. A. Leonova ◽  
V. A. Bobrov ◽  
V. P. Shevchenko ◽  
A. A. Prudkovskii

Author(s):  
Boris Krasnoyarskiy ◽  
Boris Krasnoyarskiy ◽  
Asya Ovsepyan ◽  
Asya Ovsepyan ◽  
Yury Fedorov ◽  
...  

The article analyzes the data of expedition studies conducted by the team of the leading scientific school of Professor Fedorov Yu.A. in the Archangelsk region for more then 10-years period of researches. The materials of mercury content obtained for samples of bottom sediments sampled in the mouth area of the Northern Dvina River, the lakes of Arkhangelsk and the surrounding areas, at Dvina Bay and different areas of the White Sea. Based on the available data and having considered the results of the authors working on the subject of mercury pollution in the subarctic region, conclusions about the level of anthropogenic impact on water bodies and streams of the Arkhangelsk region are justified. Factors that contribute to the formation of relatively high and low concentrations of mercury in sediments identified. The effects of mechanical, hydrochemical, hydrological barriers analyzed. The natural background of mercury in the bottom sediments of the region revealed. Comparative analysis of the accumulation of mercury in the bottom sediments of the study area and other parts of the subarctic region realized. Opportunities and conditions for existence of the effect of "secondary pollution" discussed.


2019 ◽  
Vol 485 (2) ◽  
pp. 221-225
Author(s):  
V. V. Kolka ◽  
O. P. Korsakova ◽  
N. B. Lavrova ◽  
T. S. Shelekhova ◽  
N. E. Zaretskaya

This paper reports on the lithological, micropaleontological, and chronometric data (radiocarbon dating) for one of the areas of the White Sea coast. The sedimentary sequences were studied in the current lake basins, which were separated from the large basin at different times. The basin was situated in the head of the current Onega Bay. On the basis of these data, the bottom sediments were stratified and the Late Pleistocene-Holocene paleogeographic settings were reconstructed for the southeastern part of Onega Bay.


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