Baumann Nils, Arnold Thuro, Foerstendorf Harald, Read David
Institute of Radiochemistry, FZ Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden, Germany.
Environ Sci Technol. 2008 Nov 15;42(22):8266-9. doi: 10.1021/es800801h.
The alteration of a depleted uranium (DU) disk in contact with a synthetic pore water, as a simulantforfertilized agricultural soil, was studied by exposing the DU to a calcium phosphate solution (2.5 x 10(-3) M Ca, 1 x 10(-3) M P). Within 12 months this contact resulted in the formation of a thin film of a secondary uranium mineral on the metallic DU. The reaction product was analyzed with both time-resolved laser-induced fluorescence spectroscopy (TRLFS) and infrared spectroscopy. Both techniques identified the reaction product on DU as a uranium(VI) phosphate phase, but only TRLFS provided its unequivocal identification as meta-autunite based on the positions of the fluorescence emission maxima at 487.8, 502.0, 523.6, 547.0, 572.1, and 600.6 nm and fluorescence lifetimes of 410 +/- 15 and 3300 +/- 310 ns. These results highlight the enhanced performance and sensitivity of the TRLFS technique for mineralogical characterization of thin surface films. Furthermore, they demonstrate that the dissolution of uranium from DU projectiles under the conditions described here is limited by the development and solubility of a meta-autunite secondary phase. The findings have helped clarify the interactions of DU ammunition with phosphate-rich soil-water.
通过将贫铀（DU）暴露于磷酸钙溶液（2.5×10⁻³ M Ca，1×10⁻³ M P）中，研究了与模拟施肥农业土壤的合成孔隙水接触的贫铀盘的变化情况。在12个月内，这种接触导致在金属贫铀上形成了一层次生铀矿物薄膜。用时间分辨激光诱导荧光光谱法（TRLFS）和红外光谱法对反应产物进行了分析。两种技术都将贫铀上的反应产物鉴定为铀（VI）磷酸盐相，但只有TRLFS根据487.8、502.0、523.6、547.0、572.1和600.6 nm处荧光发射最大值的位置以及410±15和3300±310 ns的荧光寿命，明确将其鉴定为变钙铀云母。这些结果突出了TRLFS技术在薄表面膜矿物学表征方面的卓越性能和灵敏度。此外，它们表明在此处所述条件下，贫铀弹丸中铀的溶解受到变钙铀云母次生相的形成和溶解度的限制。这些发现有助于阐明贫铀弹药与富含磷酸盐的土壤 - 水之间的相互作用。
