title: Cesium adsorption/desorption behavior of clay minerals considering actual contamination conditions in Fukushima.
abstract: Cesium adsorption/desorption experiments for various clay minerals, considering actual contamination conditions in Fukushima, were conducted using the (137)Cs radioisotope and an autoradiography using imaging plates (IPs). A 50 μl solution containing 0.185 ~ 1.85 Bq of (137)Cs (10(-11) ~ 10(-9 )molL(-1) of (137)Cs) was dropped onto a substrate where various mineral particles were arranged. It was found that partially-vermiculitized biotite, which is termed "weathered biotite" (WB) in this study, from Fukushima sorbed (137)Cs far more than the other clay minerals (fresh biotite, illite, smectite, kaolinite, halloysite, allophane, imogolite) on the same substrate. When WB was absent on the substrate, the amount of (137)Cs sorbed to the other clay minerals was considerably increased, implying that selective sorption to WB caused depletion of radiocesium in the solution and less sorption to the coexisting minerals. Cs-sorption to WB continued for about one day, whereas that to ferruginous smectite was completed within one hour. The sorbed (137)Cs in WB was hardly leached with hydrochloric acid at pH 1, particularly in samples with a longer sorption time. The presence/absence of WB sorbing radiocesium is a key factor affecting the dynamics and fate of radiocesium in Fukushima.
authors: Graduate School of Sciences, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
authors: Hiroki
authors: H
authors: Mukai
authors: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors: Atsushi
authors: A
authors: Hirose
authors: Graduate School of Sciences, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
authors: Satoko
authors: S
authors: Motai
authors: Graduate School of Sciences, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
authors: Ryosuke
authors: R
authors: Kikuchi
authors: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors: Keitaro
authors: K
authors: Tanoi
authors: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors: Tomoko M
authors: TM
authors: Nakanishi
authors: Quantum Beam Science Center and Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors: Tsuyoshi
authors: T
authors: Yaita
authors: Graduate School of Sciences, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
authors: Toshihiro
authors: T
authors: Kogure