Microbial hydrogen sinks in the sand-bentonite backfill material for the deep geological disposal of radioactive waste.

Autor: Rolland C; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Burzan N; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Leupin OX; National Cooperative for the Disposal of Radioactive Waste, Wettingen, Switzerland., Boylan AA; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Frutschi M; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Wang S; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Jacquemin N; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Bernier-Latmani R; Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Jazyk: angličtina
Zdroj: Frontiers in microbiology [Front Microbiol] 2024 Apr 16; Vol. 15, pp. 1359677. Date of Electronic Publication: 2024 Apr 16 (Print Publication: 2024).
DOI: 10.3389/fmicb.2024.1359677
Abstrakt: The activity of subsurface microorganisms can be harnessed for engineering projects. For instance, the Swiss radioactive waste repository design can take advantage of indigenous microorganisms to tackle the issue of a hydrogen gas (H 2 ) phase pressure build-up. After repository closure, it is expected that anoxic steel corrosion of waste canisters will lead to an H 2 accumulation. This occurrence should be avoided to preclude damage to the structural integrity of the host rock. In the Swiss design, the repository access galleries will be back-filled, and the choice of this material provides an opportunity to select conditions for the microbially-mediated removal of excess gas. Here, we investigate the microbial sinks for H 2 . Four reactors containing an 80/20 (w/w) mixture of quartz sand and Wyoming bentonite were supplied with natural sulfate-rich Opalinus Clay rock porewater and with pure H 2 gas for up to 108 days. Within 14 days, a decrease in the sulfate concentration was observed, indicating the activity of the sulfate-reducing bacteria detected in the reactor, e.g., from Desulfocurvibacter genus. Additionally, starting at day 28, methane was detected in the gas phase, suggesting the activity of methanogens present in the solid phase, such as the Methanosarcina genus. This work evidences the development, under in-situ relevant conditions, of a backfill microbiome capable of consuming H 2 and demonstrates its potential to contribute positively to the long-term safety of a radioactive waste repository.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
(Copyright © 2024 Rolland, Burzan, Leupin, Boylan, Frutschi, Wang, Jacquemin and Bernier-Latmani.)
Databáze: MEDLINE
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