微生物起源Mn酸化物による放射性Csの新規固定機構の解明

2015 Fiscal Year Annual Research Report

• Project/Area Number: 26820410
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Yu QianQian 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 先端基礎研究センター, 研究員 (90712018)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: Cs decontamination / biomaterial / Mn oxide / XAFS

Outline of Annual Research Achievements

The accident at Fukushima Daiichi nuclear power plant resulted in an abruptly release of huge amounts of Cs into the environment. Mn oxide is known to be a scavenger for metallic ions in nature, because it has a large specific surface area, and low point of zero charge. Mn oxides are ubiquitous in soil, which may affect the migration of radioactive Cs in Fukushima forest. Unfortunately, reported results based on chemical and spectroscopic analysis using stable Cs could not clarify the migration behavior of radioactive Cs at ultralow concentration.
In this work, sorption and desorption behavior of Cs on Mn oxides over a wide range of concentrations were studied using 137Cs as an isotope tracer. Several new results were observed:
1) Multiple sorption sites were observed on both layer and tunnel types of Mn oxides.
2) For biogenic birnessite, trace amount of competitive ions located at mineral surface largely affected Cs sorption at low ionic strength.
3) Compared with clay minerals, layer type Mn oxide possesses a higher sorption capacity of Cs, with a lower affinity.
4) Tunnel structured Mn oxide has much higher affinity to Cs at ultralow molar concentrations, which may contribute to the fixation of Cs.

Research Products

• [Journal Article] Fungus-promoted transformation of lanthanides during the biooxidation of divalent manganese (2016)
  • Author(s): Q. Yu, T. Ohnuki, K. Tanaka, N. Kozai, S. Yamasaki, F. Sakamoto, Y. Tani
  • Journal Title: Geochimica et Cosmochimica Acta Volume: 174 Pages: 1-12
  • DOI: 10.1016/j.gca.2015.11.004
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Microwave-assisted hydrothermal synthesis of nanocrystalline lithium-ion sieve from biogenic manganese oxide, its characterization and lithium sorption studies. (2015)
  • Author(s): Q. Yu, K. Sasaki
  • Journal Title: Hydrometallurgy Volume: - Pages: -
  • DOI: 10.1016/j.hydromet.2015.10.002
  • Peer Reviewed
• [Journal Article] Sorption of trivalent cerium by a mixture of microbial cells and manganese oxides: Effect of microbial cells on the oxidation of trivalent cerium (2015)
  • Author(s): T. Ohnuki, M. Jiang, F. Sakamoto, N. Kozai, S. Yamasaki, Q. Yu, K. Tanaka, S. Utsunomiya, X. Xia, K. Yang, J. He,
  • Journal Title: Geochimica et Cosmochimica Acta Volume: 163 Pages: 1-13
  • DOI: 10.1016/j.gca.2015.04.043
  • Peer Reviewed
• [Presentation] The role of microorganisms in activation of manganese oxidants for enhanced oxidative removal of Co(II) (2016)
  • Author(s): Qianqian Yu
  • Organizer: 28th ASRC workshop
  • Place of Presentation: Japan Atomic Energy Agency (Tokai-mura, Ibaraki)
  • Year and Date: 2016-02-25 – 2016-02-26
  • Int'l Joint Research
• [Presentation] Microbe activity promoted transformation of lanthanide and actinide (2015)
  • Author(s): Qianqian Yu
  • Organizer: 第3回日中大学間核燃料サイクル学術討論会
  • Place of Presentation: Tokyo Institute of Technology (Meguro-ku, Tokyo)
  • Year and Date: 2015-12-01 – 2015-12-03
  • Int'l Joint Research