Surface and bacterial reduction of nitrate at alkaline pH: Conditions comparable to a nuclear waste repository

Yan Rafrafi (1) , Harifidy Ranaivomanana (2) , Alexandra Bertron (2) , Achim Albrecht (3) , Benjamin Erable (1)

1 LGC - Laboratoire de Génie Chimique
2 LMDC - Laboratoire Matériaux et Durabilité des constructions
3 ANDRA - Agence Nationale pour la Gestion des Déchets Radioactifs

This study investigates the reactivity of nitrates in abiotic and biotic conditions at alkaline pH in the context of a repository for long-lived inter-mediate-level radioactive waste. The work, carried out under environmental conditions comparable to those prevailing in the repository: alkaline pH, no oxygen, solid materials (cementitious material, steel), aims to identify the by-products of the nitrate reduction and to evaluate reaction kinetics of these reactions with and without the presence of denitrifying microorganisms. This paper demonstrates that, even at the high pH characteristic of nuclear waste repositories, nitrate reduction may be a likely scenario, with biotic catalysis in the presence of microorganisms and surface catalysis in the presence of steel and/or corrosion products.

Mots clés: Alkaline conditions; Nitrate reduction; Concrete cells; Nuclear waste repositories; Halomonas desiderata; Biofilms

Domaines: Génie chimique; Génie des procédés

Yan Rafrafi, Harifidy Ranaivomanana, Alexandra Bertron, Achim Albrecht, Benjamin Erable. Surface and bacterial reduction of nitrate at alkaline pH: Conditions comparable to a nuclear waste repository. International Biodeterioration and Biodegradation, 2015, vol. 101, pp. 12-22. ⟨10.1016/j.ibiod.2015.03.013⟩. ⟨hal-01150718⟩