A soil profile was sampled in 2002 from a soil in which a depleted uranium (DU) ammunition penetrator was embedded for seven years, since the Bosnian conflict in 1994-1995. The affinity of the uranium for six different geochemical phases within the soil profile was assessed by sequential extraction (based on Tessier et al., 1979). The highest concentrations of uranium were present in the surface layers of the soil, 10.5 ± 0.05 g kg⁻¹ (0-4 cm depth) and 7.3 ± 0.02 g kg⁻¹ (4-10 cm depth), from which the penetrator was removed. Sequential extraction results indicated that the uranium is dominantly extracted by the 'bound to carbonate' extraction, with significant concentrations also recovered using the 'readily exchangeable', 'bound to organic matter' and 'bound to Fe/Mn oxyhydroxides' extraction reagents. The recovered uranium concentrations are considered to be operationally-defined. Isotopic analysis determined that ²³⁸U/²³⁵U ratios ranged from 58-168 compared with a natural value of 138. XPS analysis indicated that uranium at the surface of a DU fragment, sampled from the soil profile, was present in the U(VI) oxidation state, and therefore the weathered DU product at the surface of the fragment is thought to be schoepite.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:495640 |
| Date | January 2008 |
| Creators | Alison Elizabeth, alison elizabeth |
| Publisher | University of Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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