| abstract |
An adsorbent for radioelement-containing waste composed of the following spherical layered double hydroxide (A) or spherical metal hydroxide (B) is provided. (A) is a nonstoichiometric compound represented by general formula (a) or (b): [M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .mH 2 O] x− . . . (a), [Al 2 Li(OH) 6 ] x+ [A n− x/n .mH 2 O] x− . . . (b) wherein 0.1≦x≦0.4, 0<m, n represents a natural number of 1 to 4, M 2+ represents at least one divalent metal, M 3+ represents at least one trivalent metal, and A n− represents at least one n-valent ion-exchangeable anion, and (B) is a spherical metal hydroxide containing a metal selected from the group consisting of the metal atoms belonging to Group II, Group IV, Group V, Group VI, Group XI, Group XII, and Group XIII of the periodic table, and the group consisting of Mn, Fe, Co, Ni, Pb, and Bi. This adsorbent can efficiently adsorb and collect volatile iodine, a radioactive anion in wastewater, and the like, provides a solidified article having excellent crack resistance after a solidification treatment, and realizes effective confinement of the radioelement-containing waste and long-term stability thereof. |