†CEA, DEN, DTN/SMTA/LMTE, 13108 Saint Paul lez Durance, France.
‡CEA, DEN, DANS/DPC/SEARS/LISL, F91191 Gif-sur-Yvette, France.
Environ Sci Technol. 2015 Jun 16;49(12):7483-90. doi: 10.1021/acs.est.5b00693. Epub 2015 Jun 2.
The current projects for the disposal of high-level radioactive waste rely on underground burial and confinement by metallic envelopes that are susceptible to corrosion processes. The impact of microbial activity must be fully clarified in order to provide biological parameters for predictive reactive transport models. This study investigates the impact of hydrogenotrophic iron-reducing bacteria (Shewanella oneidensis strain MR-1) on the corrosion rate of carbon steel under simulated geological disposal conditions by using a geochemical approach. It was found that corrosion damage changes mostly according to the experimental solution (i.e., chemical composition). Magnetite and vivianite were identified as the main corrosion products. In the presence of bacteria, the corrosion rate increased by a factor of 1.3 (according to weight loss analysis) to 1.8 (according to H2 measurements), and the detected amount of magnetite diminished. The mechanism likely to enhance corrosion is the destabilization and dissolution of the passivating magnetite layer by reduction of structural Fe(III) coupled to H2 oxidation.
当前，高放废物的处置主要依赖于地下埋藏和金属外壳的隔离，但金属外壳易受到腐蚀过程的影响。为了给预测反应传输模型提供生物参数，必须充分阐明微生物活动的影响。本研究通过地球化学方法，研究了氢营养型铁还原菌（希瓦氏菌属 MR-1 菌株）对模拟地质处置条件下碳钢腐蚀速率的影响。结果发现，腐蚀损伤主要根据实验溶液（即化学成分）而变化。鉴定出磁铁矿和磷铁矾是主要的腐蚀产物。在细菌存在的情况下，腐蚀速率增加了 1.3 倍（根据重量损失分析）至 1.8 倍（根据 H2 测量），并且检测到的磁铁矿量减少。可能增强腐蚀的机制是通过与 H2 氧化耦合的结构 Fe(III)的还原使钝化磁铁矿层失稳和溶解。
