Sorption and reduction of Neptunium(V) on the surface of iron oxides

Nakata, Kotaro*; Nagasaki, Shinya*; Tanaka, Satoru*; Sakamoto, Yoshiaki ; Tanaka, Tadao ; Ogawa, Hiromichi

Sorption and desorption experiments of Np on magnetite and hematite under aerobic and anaerobic conditions were carried out to investigate the possibility of reduction of Np(V) to Np(IV) on the surfave of iron oxides including Fe(II). The results indicated that Np sorption mechanism on magnetite under anaerobic condition was completely different from that under aerobic condition. The evidence of the presence of Np(IV) on magnetite surface after sorption was obtained from the extraction experiment with TTA/xylene solution.