Handley-Sidhu Stephanie, Worsfold Paul J, Boothman Christopher, Lloyd Jonathan R, Alvarez Rebeca, Livens Francis R, Vaughan David J, Keith-Roach Miranda J
Biogeochemistry and Environmental Analytical Chemistry Research Group, School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
Environ Sci Technol. 2009 Jan 15;43(2):350-5. doi: 10.1021/es8021842.
The testing of armor-piercing depleted uranium (DU) "penetrators" has resulted in the deposition of DU in the sediments of the Solway Firth, UK. In this study, DU-amended, microcosm experiments simulating Solway Firth sediments under high (31.5) and medium (16.5) salinity conditions were used to investigate the effect of salinity and biogeochemical conditions on the corrosion and fate of DU, and the impact of the corroding DU on the microbial population. Under suboxic conditions, the average corrosion rates were the same forthe 31.5 and 16.5 salinity systems at 0.056 +/- 0.006 g cm(-2) y(-1), implying that complete corrosion of a 120 mm penetrator would take approximately 540 years. Under sulfate-reducing conditions, corrosion ceased due to passivation of the surface. Corroding DU resulted in more reducing conditions and decreased microbial diversity as indicated by DNA sequencing and phylogenetic analysis. The lack of colloidal and particulate DU corrosion products, along with measurable dissolved U and a homogeneous association of U with the sediment, suggest that U was transported from the penetrator surface into the surrounding environment through dissolution of U(VI), with subsequent interactions resulting in the formation of secondary uranium species in the sediment.
对贫铀穿甲“弹芯”的测试导致贫铀沉积在英国索尔韦湾的沉积物中。在本研究中，利用贫铀改良的微观实验，模拟高盐度（31.5）和中等盐度（16.5）条件下的索尔韦湾沉积物，以研究盐度和生物地球化学条件对贫铀腐蚀及归宿的影响，以及贫铀腐蚀对微生物群落的影响。在缺氧条件下，盐度为31.5和16.5的系统平均腐蚀速率相同，为0.056±0.006 g cm⁻² y⁻¹，这意味着一个120毫米的弹芯完全腐蚀大约需要540年。在硫酸盐还原条件下，由于表面钝化，腐蚀停止。DNA测序和系统发育分析表明，贫铀腐蚀导致更多的还原条件和微生物多样性降低。缺乏胶体和颗粒状贫铀腐蚀产物，以及可测量的溶解铀和铀与沉积物的均匀结合，表明铀通过U(VI)的溶解从弹芯表面输送到周围环境中，随后相互作用导致沉积物中形成次生铀物种。
