Radiation-induced reduction of metal ions in aqueous solution systems and its application

固体酸化物-水溶液系での金属イオンの放射線誘起還元とその利用に関する研究

永石 隆二 ; 青柳 登   ; 山田 禮司; 籏野 嘉彦; 吉田 善行

Nagaishi, Ryuji; Aoyagi, Noboru; Yamada, Reiji; Hatano, Yoshihiko; Yoshida, Zenko

線又は電子線を照射した水溶液中でクロムや白金族元素の高酸化状態の金属イオンの反応挙動を研究した。放射線照射下の水溶液中で見かけ上反応しない金属イオンも、アルミナなどの固体酸化物を水溶液に添加することで還元が促進された。さらに、生成した沈殿/固体への吸着物が促進還元に寄与することを明らかにした。これらを定量的に議論するとともに、この反応系の有害金属の無害化や有用金属の回収・利用への応用並びに高レベル放射性廃棄物の放射線源利用の手法を提案した。

Promotion of chemical reactions by adding oxide particles to aqueous solution under the irradiation of ionizing radiations has been paid attention especially from the practical viewpoint, so that hydrogen production and decomposition of toxic organic compounds studied. On the other hand, redox of metal ions has not been studied very much since successive reactions after the redox become complicated. In the present study, reduction behavior of metal ions in aqueous solution systems irradiated by -ray and electron beam was measured, the reduced amount was compared with that by water radiolysis, and then the promotion of reduction by adding oxide particles was found out quantitatively. The application of reduction system to treatment of toxic substances in industry and environment, and to recovery of useful materials from high-level radioactive wastes (HLW), and the utilization of HLW as a radiation resource were also proposed.