Deep-water profiling of 137Cs and 90Sr in the Black Sea: a further insight into dynamics of the post-Chernobyl radioactive contamination

Abstract

The first post-Chernobyl measurements of vertical distribution of 137 Cs in the abyssal Black Sea waters have been conducted in the vicinity of submarine canyon Viteaz together with profiling of 90 Sr. This allowed showing an increase in 137 Cs concentration and the low 90 Sr/ 137 Cs activity ratio (&0.2) at 1,000 m water depth, suggesting the long-distance influence of the Danube River runoff through the Viteaz Canyon. Calculation of inventories of 90 Sr and 137 Cs in oxic and anoxic Black Sea waters and their comparison with the total input of these radionuclides to the Black Sea after the Chernobyl accident have revealed considerable accumulation of them in the deep water column.

Estimation of 137Cs Distribution and Recovery Using Various Types of Sorbents in the Black Sea Surface Layer

“…Further research is needed in the coastal ecosystems of the Black Sea, which are accumulators of anthropogenic radionuclides. According to the literature data, 137 Cs activity in the Black Sea was 20.0 ± 1.1 Bq/m 3 in 2007 [7], 17.1 ± 0.9 Bq/m 3 in 2013 [6], and 14.4 ± 1.3 Bq/m 3 in 2015 [39]. The data obtained are consistent with the published data [6,7,39], taking into account the half-life for the decrease in 137 Cs inventory, which, according to [38], is 8.6 years for the period 1987-2011.…”

“…According to the literature data, 137 Cs activity in the Black Sea was 20.0 ± 1.1 Bq/m 3 in 2007 [7], 17.1 ± 0.9 Bq/m 3 in 2013 [6], and 14.4 ± 1.3 Bq/m 3 in 2015 [39]. The data obtained are consistent with the published data [6,7,39], taking into account the half-life for the decrease in 137 Cs inventory, which, according to [38], is 8.6 years for the period 1987-2011. The decrease in 137 Cs activity in the surface layer of the Black Sea is associated with its radioactive decay and penetration into the underlying layers [38].…”

“…Egorov et al [3]. Staneva et al [4] performed a mathematical modeling of 137 Cs distribution, and the current state of the issue was described in several articles by S. Gulin et al [5,6] and R. Delfanti et al [7]. Many methods for the radioanalytical determination of 137 Cs have been developed [8].…”

137CS concentrations in surface waters of the seas of Eurasia: results of expeditionary research in 2017

“…Для определения содержания цезия-137 в пробах поверхностной морской воды был использован метод, основанный на его концентрировании с помощью проточной сорбции в двух последовательно соединенных адсорберах с последующим измерением содержания 137 Cs по гамма-излучению дочернего радионуклида 137m Ba (Gulin et al, 2015). Воду прокачивали с помощью перистальтического насоса Elpan 372.C (Польша) через полипропиленовый фильтр с номинальным размером пор 0.5 мкм для удаления взвешенного вещества.…”

New Sorbents Based on Polyacrylonitrile Fiber and Transition Metal Ferrocyanides for 137Cs Recovery from Various Composition Solutions

“…However, it should be noted that sorbents based on AMP are prone to adsorption of 40 K, which leads to an overestimation of the result of measuring 137 Cs activity; therefore, sorbents based on transition metal ferrocyanides are preferable [4]. Transition metal ferrocyanides can be used to extract 137 Cs in pure form [12] or deposited on a support: PAN fiber (KNiFC-PAN) [4,13,14], silica gel (SiO 2 -KMCHCF [15], FSS [16], FC-Cu-EDA-SAMMS [17]), aluminosilicates (Niket-k) [18,19], chitin-containing materials (FFCG-SO 4 -FC [20], Mikoton-Cs [21], CFC Zn-K, CFC Cu-K, CPC Ni-K [22]), hydrated zirconium dioxide (Thermoxide 35) [16,23,24], activated carbon (C/NiHCFe, C/InHCFe, C/CuHCFe) [25], cellulose support (Anfezh [16,19,26], Uniket [18], NKF-C [27,28], FN and FN-50 [19,29]), natural minerals (diatomite (FND) [19,24], tripolite [30], clinoptilolite (NPF-CL) and quartz-glauconite concentrate (NPF-GL) [23,31,32]) and others. Zeoliteimidazole frameworks [33], mesoporous silica gels [34], aerogels [35], and hydrogels [36], which showed high sorption characteristics in cesium recovery, should be mentioned as new promising supports.…”