title: Speciation analysis of ¹²⁹I, ¹³⁷Cs, ²³²Th, ²³⁸U, ²³⁹Pu and ²⁴⁰Pu in environmental soil and sediment.
abstract: The environmental mobility and bioavailability of radionuclides are related to their physicochemical forms, namely species. We here present a speciation analysis of important radionuclides including (129)I (also (127)I), (137)Cs, (232)Th, (238)U and plutonium isotopes ((239)Pu and (240)Pu) in soil (IAEA-375) and sediment (NIST-4354) standard reference materials and two fresh sediment samples from Øvre Heimdalsvatnet Lake, Norway. A modified sequential extraction protocol was used for the speciation analysis of these samples to obtain fractionation information of target radionuclides. Analytical results reveal that the partitioning behaviour, and thus the potential mobility and bioavailability, are exclusively featured for the individual radionuclide. Iodine is relatively mobile and readily binds to organic matter, while plutonium is mainly bound to both organic matter and nitric acid leachable fractions. Thorium is predominated in nitric acid leachable fraction and caesium is primarily observed in nitric acid and aqua regia leachable fractions and residue. Our analytical results reveal that around 50% of uranium might still remain in the residue which could not be extracted with aggressive acid, namely, aqua regia.
authors: Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Jixin
authors: J
authors: Qiao
authors: Violeta
authors: V
authors: Hansen
authors: Xiaolin
authors: X
authors: Hou
authors: Ala
authors: A
authors: Aldahan
authors: Göran
authors: G
authors: Possnert