Biogeochemical Factors of Cs, Sr, U, Pu Immobilization in Bottom Sediments of the Upa River, Located in the Zone of Chernobyl Accident

• Published in: Biology (Basel, Switzerland) Vol. 12; no. 1; p. 10
• Main Authors: Zelenina, Darya, Kuzmenkova, Natalia, Sobolev, Denis, Boldyrev, Kirill, Namsaraev, Zorigto, Artemiev, Grigoriy, Samylina, Olga, Popova, Nadezhda, Safonov, Alexey
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21-12-2022; MDPI
• Subjects: Ammonium; Ammonium sulfate; Bacteria; Biogeochemistry; Biomass; bioremediation; Experiments; freshwater bodies; Immobilization; Iron-reducing bacteria; Nuclear power plants; Phosphorus; Phytoplankton; Potassium; Precipitation; Pyrite; Radioisotopes; Rivers; Sediments; Sodium; Russia; Cs; freshwater bodies; bioremediation; biomineralization; Pu; U; phytoplankton; sediments; Sr
• ISSN: 2079-7737; 2079-7737
• DOI: 10.3390/biology12010010

Laboratory modeling of Cs, Sr, U, Pu immobilization by phytoplankton of the river Upa, affected after the Chernobyl accident, has been carried out. Certain conditions are selected for strong fixation of radionuclides in bottom sediments due to biogeochemical processes. The process of radionuclide removal from the water phase via precipitation was based on their accumulation by phytoplankton, stimulated by nitrogen and phosphorus sources. After eight days of stimulation, planktonic phototrophic biomass, dominated by cyanobacteria of the genus
, appears in the water sample. The effectiveness of U, Pu and Sr purification via their transfer to bottom sediment was observed within one month. The addition of ammonium sulfate and phosphate (Ammophos) led to the activation of sulfate- and iron-reducing bacteria of the genera
,
,
,
,
,
,
,
,
, which form sulphide ferrous precipitates such as pyrite, wurtzite, hydrotroillite, etc., in anaerobic bottom sediments. The biogenic mineral composition of the sediments obtained under laboratory conditions was verified via thermodynamic modeling.