Development of high-resolution analytical techniques for heavy metal ions sorbed to terrestrial surface materials and elucidation of their sorption mechanism

2015 Fiscal Year Final Research Report

• Project/Area Number: 24340133
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: The University of Tokyo
• Principal Investigator: Kogure Toshihiro 東京大学, 理学(系)研究科(研究院), 准教授 (50282728)
• Co-Investigator(Kenkyū-buntansha): WADA Shin-Ichiro 九州大学, 農学研究科, 教授 (60108678) ; NAKAI Izumi 東京理科大学, 理学部, 教授 (90155648)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 地球表層物質 / 粘土鉱物 / 重金属 / 吸着 / セシウム

Outline of Final Research Achievements

Considering the social importance, mineralogical aspects of radioactive soil contamination formed by Fukushima nuclear accident in March 2011 have been investigated mainly. Using specific autoradiography and electron microscopic analyses, it was found that “weathering biotite”, or partially vermiculitized biotite in weathered granite, was a major substance to fix radioactive cesium (Cs) in the soil collected from Fukushima. The sorption experiments in laboratory using very dilute radioactive Cs solutions conformed that weathered biotite was far superior to other clay minerals in sorbing Cs, if the concentration is in the actual contamination level. Moreover, the fixed Cs in weathered biotite was hardly desorbed by ion-exchange process with various electrolyte solutions. The fixation of Cs in weathered biotite was gradually strengthened with time. These results are very informative to consider the present state and future fate of the radioactive contamination around Fukushima.

Free Research Field

鉱物学、物質科学