EGU21-4106, updated on 31 May 2021
https://doi.org/10.5194/egusphere-egu21-4106
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Radiocaesium retention in bog meadows: an analysis based on soil properties

Irina Konopleva1 and Natalya Sanzharova2
Irina Konopleva and Natalya Sanzharova
  • 1Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russia (irina.konopleva@mail.ru)
  • 2Russian Institute of Radiology and Agroecology, Obninsk, Russia

The deposition of large amounts of radiocaesium from the Chernobyl Nuclear Power Plant accident (ChNPP,1986) has required a study of the fate of this long-lived radioisotope in ecosystems. Fallout radionuclide becomes incorporated into the soil biogeochemical processes and the human food chain. Usually, meadows located on polluted peat soils are intensively used for sheep and cow grazing, which results in contaminated animal products. Therefore, to suggest remediation methods for contaminated bog meadows it is necessary to find out the key factors affecting the 137Cs mobility in bog soils.

The vertical distribution of 137Cs in peat bog soils in the remote period after the Chernobyl accident was investigated. The study was conducted on bog meadows in the Bryansk region of Russia. Soil samples were taken at locations on lowland and transitional bogs.

Fifteen years after the accident, an analysis of soils showed that the peak of 137Cs activity was still in the upper 10 cm layer. This layer is usually saturated with plant roots. The highest 137Cs retention (92% of the total inventory) has been observed in the top 10 cm layer in the drained bog. The findings revealed that elevated soil moisture promotes 137Cs downward migration.

The rate of 137Cs migration is controlled by the solid-liquid distribution coefficient Kd which is related to the presence of clay minerals and cations competing for exchange sites on solid soil, such as K+ and NH4+. In wetlands with the high content of decomposed organic matter are created the conditions for intensive ammonification. This study provides evidence that ammonium is the major contributing factor for Kd values in peat soils on bog meadows.

Remediation methods aimed at enhanced removal of 137Cs from the root zone in bog soils are discussed.

 

 

 

 

How to cite: Konopleva, I. and Sanzharova, N.: Radiocaesium retention in bog meadows: an analysis based on soil properties, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4106, https://doi.org/10.5194/egusphere-egu21-4106, 2021.

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