ALBERT

Description: Oxygen, hydrogen, and carbon isotope data with the [DIC] concentrations were analyzed in water samples collected in the East Siberian Sea along the Kolyma and Indigirka sub-meridian profile in route 69 of R/V "Akademik Mstislav Keldysh" in 2017. Sampling was done using the Rosette SBE 32. Isotope analysis was performed in the laboratory of Isotope Geochemistry and Geochronology of IGEM RAS (Moscow) in 2017. Oxygen isotope composition of water samples determined by CF IRMS using the Delta V+ with the GasbenchII option (Thermo, Germany). Hydrogen isotope composition of water samples determined by DI IRMS using the DeltaPlus with H/Device option (Thermo, Germany). The δD and δ¹⁸O values were determined with an accuracy of 0.3 and 0.05 per mill correspondently. The δ¹³C(DIC) and DIC concentrations were analyzed using the Delta V+ with the GasbenchII option (Thermo, Germany). The δ¹³C(DIC) and [DIC] values were determined with an accuracy of 0.05 per mill and 5 rel. % correspondently.

Description: Oxygen and hydrogen isotope data were obtained in water samples collected in the Laptev Sea along the 130.5E meridian in route 63 of R/V "Akademik Mstislav Keldysh" in 2015 and in route 69 of R/V "Akademik Mstislav Keldysh" in 2017. Sampling was done using the Rosette SBE 32. Isotope analysis was performed in the laboratory of Isotope Geochemistry and Geochronology of IGEM RAS (Moscow) in 2015-2016 (for route 63) and in 2017 (for route 69). Oxygen isotope composition of water samples determined by CF IRMS using the Delta V+ with the GasbenchII option (Thermo, Germany). Hydrogen isotope composition of water samples determined by DI IRMS using the DeltaPlus with H/Device option (Thermo, Germany). The δD and δ¹⁸O values were determined with an accuracy of 0.3 and 0.05 per mill correspondently.

Description: This paper reports the results of the investigations of 2006-2007 on the distribution and migration forms of artificial radionuclides and chemical elements in the Ob-Irtysh water system. Three regions were studied. One of them is a local segment of the Ob River upstream from the confluence with the Irtysh River; its investigation allowed us to estimate the general radioecological state of the aquatic environment affected by the activity of the Tomsk 7 plant. The second region is a local segment of the Irtysh River upstream from its confluence with the Ob River, where the influence of emissions from the NPO Mayak could be estimated. The third region is the water area of the Ob River after its confluence with the Irtysh River. It characterizes the real level of radioactive and chemical contamination of the middle reaches of the Ob River. In order to explain horizontal variations in the distribution of radionuclides in the upper layer of bottom sediments collected at various sites, the results of sorption-kinetic experiments with radioactive tracers in the precipitate-solution system were used. The investigation of the migration forms of trace elements and radionuclides occurring in river water was based on the method of tangential-flow membrane filtration. Chemical element contents were determined in 400-ml water samples. A set of Millipore polysulfone membranes with pore sizes of 8, 1.2, 0.45, 0.1, and 0.025 µm was employed. Taking into account the ultralow specific concentrations of radionuclides in the water, they were analyzed in 300-500 litre samples using Millipore polysulfone membranes with pore sizes of 0.45 µm and 15 kDa. This allowed us to estimate the percentages of cesium-137 and plutonium-239, 240 in the suspended particulate fraction, colloids, and dissolved species.