Factors controlling .sup.137./sup.Cs distribution in bottom sediments of Koronowo Reservoir (Poland)

0561274 - GLÚ 2023 RIV DE eng J - Journal Article
Sekudewicz, I. - Matoušková, Šárka - Ciesielska, Z. - Mulczyk, A. - Gąsiorowski, M.
Factors controlling ¹³⁷Cs distribution in bottom sediments of Koronowo Reservoir (Poland).
Journal of Soils and Sediments. Roč. 22, č. 12 (2022), s. 3189-3208. ISSN 1439-0108. E-ISSN 1614-7480
Institutional support: RVO:67985831
Keywords : Cesium-137 * Potassium-40 * Lake sediments * Chernobyl fallout * Mineralogical composition * Grain-size distribution
OECD category: Geology
Impact factor: 3.6, year: 2022
Method of publishing: Open access
https://link.springer.com/article/10.1007/s11368-022-03326-5

Purpose The main aim of this study was to investigate factors influencing the long-term distribution of ¹³⁷Cs activity concentrations in the bottom sediments of the dam lake, Koronowo Reservoir, 32 years after the Chernobyl nuclear power plant accident. For this purpose, selected properties of the collected sediment samples, such as grain size, mineralogical composition, and organic matter (OM) content, were investigated. Materials and methods The samples of lake sediments were collected with a Kayak-type gravity corer. The spatial and vertical distributions of ¹³⁷Cs and ⁴⁰K activity concentrations in the bottom sediments were investigated based on gamma spectrometry measurements. The particle size distribution of surface lake sediments was determined using a laser particle size analyzer. SEM and XRD were used for the mineralogical analysis of the collected sediment samples. Additionally, the content of organic matter was examined in all samples using an elemental analyzer. Results The ¹³⁷Cs content was significantly elevated in the case of fine-grained (< 63 μm) surface lake sediments (classified as silts, which are deposited in the profundal zone of Koronowo Lake) and ranged from 12.5 ± 4.1 to 29.2 ± 4.0 Bq kg⁻¹. It was found that the increased concentration of ¹³⁷Cs activity is more closely related to the content of the silt fraction (2–63 μm) than to the clay fraction (< 2 μm) in the collected surface lake sediments. The content of clay minerals also showed a significant positive correlation with ¹³⁷Cs activity concentration in the surface lake sediments of Koronowo Lake. A similar relationship was noticed for the OM content, but it may be suspected that it is the result of radiocesium-bearing particle accumulation in OM-rich sediments. Conclusion The most important factor influencing the spatial distribution of ¹³⁷Cs activity concentrations in the surface lake sediments of Koronowo Lake, apart from the bottom morphology and grain size of sediments, is the content of clay minerals. Moreover, the increased detrital inflow to the lake after the construction of the dam could have probably affected the vertical distribution of ¹³⁷Cs activity concentrations in the bottom sediments, as evidenced by, e.g., the measurements of ⁴⁰K activity concentration.
Permanent Link: https://hdl.handle.net/11104/0336095