Microbial influence in Spanish bentonite slurry microcosms: Unveiling a-year long geochemical evolution and early-stage copper corrosion related to nuclear waste repositories.

Autor: Martinez-Moreno MF; Faculty of Sciences, Department of Microbiology, University of Granada, Granada, Spain. Electronic address: mmartinezm@ugr.es., Povedano-Priego C; Faculty of Sciences, Department of Microbiology, University of Granada, Granada, Spain., Morales-Hidalgo M; Faculty of Sciences, Department of Microbiology, University of Granada, Granada, Spain., Mumford AD; Department of Chemical Engineering, Faculty of Science and Engineering, Swansea University, Swansea, United Kingdom., Aranda E; Institute of Water Research, Department of Microbiology, University of Granada, Granada, Spain., Vilchez-Vargas R; Medical Department II, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany., Jroundi F; Faculty of Sciences, Department of Microbiology, University of Granada, Granada, Spain., Ojeda JJ; Department of Chemical Engineering, Faculty of Science and Engineering, Swansea University, Swansea, United Kingdom., Merroun ML; Faculty of Sciences, Department of Microbiology, University of Granada, Granada, Spain.
Jazyk: angličtina
Zdroj: Environmental pollution (Barking, Essex : 1987) [Environ Pollut] 2024 Oct 01; Vol. 358, pp. 124491. Date of Electronic Publication: 2024 Jul 02.
DOI: 10.1016/j.envpol.2024.124491
Abstrakt: 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 H 2 O) to copper sulfide (Cu 2 S), 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.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: