Abstract：
The deep geological repository (DGR) concept consists of storing radioactive waste in metal canisters, surrounded by compacted bentonite, and placed deeply into a geological formation. Here, bentonite slurry microcosms with copper canisters, inoculated with bacterial consortium and amended with acetate, lactate and sulfate were set up to investigate their geochemical evolution over a year under anoxic conditions. The impact of microbial communities on the corrosion of the copper canisters in an early-stage (45 days) was also assessed. The amended bacterial consortium and electron donors/acceptor accelerated the microbial activity, while the heat-shocked process had a retarding effect. The microbial communities partially oxidize lactate to acetate, which is subsequently consumed when the lactate is depleted. Early-stage microbial communities showed that the bacterial consortium reduced microbial diversity with Pseudomonas and Stenotrophomonas dominating the community. However, sulfate-reducing bacteria such as Desulfocurvibacter, Anaerosolibacter, and Desulfosporosinus were enriched coupling oxidation of lactate/acetate with reduction of sulfates. The generated biogenic sulfides, which could mediate the conversion of copper oxides (possibly formed by trapped oxygen molecules on the bentonite or driven by the reduction of H2O) to copper sulfide (Cu2S), were identified by X-ray photoelectron spectroscopy (XPS). Overall, these findings shed light on the ideal geochemical conditions that would affect the stability of DGR barriers, emphasizing the impact of the SRB on the corrosion of the metal canisters, the gas generation, and the interaction with components of the bentonite.
摘要：
深层地质资源库（DGR）的概念包括将放射性废物存储在金属罐中，被压实的膨润土包围，并放置在地质构造中。这里,膨润土泥浆微观世界与铜罐，用细菌聚生体接种，并用乙酸盐修正，建立了乳酸和硫酸盐，以研究它们在缺氧条件下一年的地球化学演化。还评估了微生物群落对早期（45天）铜罐腐蚀的影响。修改后的细菌聚生体和电子供体/受体加速了微生物活性，而膨润土热冲击过程有缓凝作用。微生物群落将乳酸盐部分氧化为乙酸盐,其随后在乳酸盐耗尽时被消耗。早期微生物群落表明，细菌群落减少了微生物多样性，假单胞菌和寡食单胞菌占主导地位。然而,硫酸盐还原细菌，如脱硫杆菌，厌氧细菌,和Desulfosporosinus富集了乳酸/乙酸的偶联氧化和硫酸盐的还原。产生的生物硫化物可以介导铜氧化物（可能是由膨润土上捕获的氧分子形成的或由H2O还原驱动的）转化为通过X射线光电子能谱（XPS）鉴定的硫化铜（Cu2S）。总的来说,这些发现揭示了影响DGR屏障稳定性的理想地球化学条件，强调SRB对金属罐腐蚀的影响，气体的产生，以及与膨润土成分的相互作用。
