Practical Removal of Radioactivity from Sediment Mud in a Swimming Pool in Fukushima, Japan by Immobilized Photosynthetic Bacteria

• Published in: Bioscience, biotechnology, and biochemistry Vol. 76; no. 4; pp. 859 - 862
• Main Authors: SASAKI, Ken, MORIKAWA, Hiroyo, KISHIBE, Takashi, MIKAMI, Ayaka, HARADA, Toshihiko, OHTA, Masahiro
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 2012; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Adsorption; Alginates - chemistry; Bacteria; Batch Cell Culture Techniques; Biochemistry; Biodegradation, Environmental; Biological and medical sciences; Biological Transport - physiology; Biotechnology; Cells, Immobilized - chemistry; Cells, Immobilized - physiology; Cesium Radioisotopes - isolation & purification; Cesium Radioisotopes - metabolism; Fukushima; Fundamental and applied biological sciences. Psychology; Glucuronic Acid - chemistry; Hexuronic Acids - chemistry; Humans; Hydrogen-Ion Concentration; immobilized photosynthetic bacteria; Japan; Mud; Nitric Acid - chemistry; nitric acid treatment; radioactive cesium; Radioactive Hazard Release; Radioactivity; Rhodobacter sphaeroides - chemistry; Rhodobacter sphaeroides - physiology; Sediments; Static Electricity; Swimming Pools; Transport; water containing sediment mud; Asia; Japan; Water; radioactive cesium; Treatment; nitric acid treatment; water containing sediment mud; Fukushima; Bacteria; immobilized photosynthetic bacteria; Photosynthesis; Sediments; Mud
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.110853

About 90% of the radioactive Cs in the sediment mud of a school's swimming pool in Fukushima, Japan was removed by treatment for 3 d using the alginate immobilized photosynthetic bacterium Rhodobcater sphaeroides SSI. Even though batch treatment was carried out 3 times repeatedly, the activity of immobilized cells in removing Cs was maintained at levels of about 84% (second batch) and 78% (third batch). Cs was strongly attached to the sediment mud because, even with HNO 3 treatment at pH of 2.00-1.60 for 24 h, it was not eluted into the water. Furthermore, more than 75% of the Cs could be removed without solubilization with HNO 3 . This suggests that the Cs attached to the sediment mud was transformed into immobilized cells via the Cs + ion by the negative charge of the immobilized cell surface and/or the potassium transport system of the photosynthetic bacterium.