Biogeochemistry and Environmental Analytical Chemistry Research Group, School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
Chemosphere. 2009 Nov;77(10):1434-9. doi: 10.1016/j.chemosphere.2009.08.053. Epub 2009 Sep 23.
The firing of depleted uranium (DU) weapons during conflicts and military testing has resulted in the deposition of DU in a variety of sand-rich environments. In this study, DU-amended dune sand microcosm and column experiments were carried out to investigate the corrosion of DU and the transport of corrosion products. Under field-moist conditions, DU corroded to metaschoepite ((UO(2))(8)O(2)(OH)(12).(H(2)O)(10)) at a rate of 0.10+/-0.012 g cm(-2)y(-1). This loosely bound corrosion product detached easily from the coupon and became distributed heterogeneously within the sand. The corrosion of DU caused significant changes in the geochemical environment, with NO(3)(-) and Fe(III) reduction observed. Column experiments showed that transport of metaschoepite was mainly dependent on its dissolution and the subsequent interaction of the resulting dissolved uranyl (UO(2)(2+)) species with sand particles. The modelling results predict that the transport of U released from metaschoepite dissolution is retarded, due to a slowly desorbing surface species (first order desorption rate constant=5.0 (+/-1.0)x10(-8)s(-1)). The concentrations of U eluting from the metaschoepite column were orders of magnitude higher than the World Health Organisation's recommended maximum admissible concentration for U in drinking water of 15 microg L(-1). Therefore, a relatively high level of mobile U contamination would be expected in the immediate proximity of a corroding penetrator in a sand-rich environment.
贫铀（DU）武器在冲突和军事试验中的发射导致 DU 在各种富含沙子的环境中沉积。在这项研究中，进行了 DU 修正沙丘砂微观和柱实验，以研究 DU 的腐蚀和腐蚀产物的传输。在现场潮湿条件下，DU 以 0.10+/-0.012 g cm(-2)y(-1)的速率腐蚀为偏铀矿((UO(2))(8)O(2)(OH)(12).(H(2)O)(10))。这种松散结合的腐蚀产物很容易从样品上脱落，并在沙子中不均匀地分布。DU 的腐蚀导致地球化学环境发生重大变化，观察到 NO(3)(-)和 Fe(III)还原。柱实验表明，偏铀矿的迁移主要取决于其溶解以及随后溶解的铀酰 (UO(2)(2+)) 物种与沙子颗粒的相互作用。建模结果预测，由于缓慢解吸的表面物种（一级解吸速率常数=5.0 (+/-1.0)x10(-8)s(-1)），从偏铀矿溶解中释放的 U 的迁移会受到延迟。从偏铀矿柱中洗脱的 U 的浓度比世界卫生组织推荐的饮用水中 U 的最大允许浓度 15 微克 L(-1)高出几个数量级。因此，在富含沙子的环境中，腐蚀穿透体附近预计会出现相对较高水平的可移动 U 污染。
