Specific sorption behavior of actinoids on biogenic Mn oxide

生物起源Mn酸化物へのアクチノイドの特異吸着

田中 万也*  ; 谷 幸則*; 大貫 敏彦

Tanaka, Kazuya*; Tani, Yukinori*; Onuki, Toshihiko

生物起源Mn酸化物へのTh, U, Npの吸着を調べた結果、吸着の序列は、合成Mn酸化物についての結果と異なり、Thの吸着が合成Mn酸化物に比べて小さかった。この原因は微生物が排出する有機物にThが配位したことであると考えられる。

We made sorption experiments of actinides on Mn oxide in dilute NaCl solution. Sorption affinity of actinides on synthetic Mn oxide was Th(IV) U(VI) Np(V). The specific sorption behavior of actinides on biogenic Mn oxide was observed. Thorium sorbed on biogenic Mn oxide was desorbed into solution with increasing time. Neptunium was not sorbed on biogenic Mn oxide. The specific sorption behavior is possibly due to organic ligands released from microorganisms and surface property of biogenic Mn oxide.