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TitreStable isotopes of nitrate reflect natural attenuation of propellant residues on military training ranges
AuteurBordeleau, G; Savard, M M; Martel, R; Smirnoff, A; Ampleman, G; Thiboutot, S
SourceEnvironmental Science & Technology (ES & T) vol. 47, no. 15, 2013 p. 8265-8272,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120361
ÉditeurACS Paragon Plus Environment
Documentpublication en série
Mediapapier; en ligne; numérique
Sujetsnitrate; azote; rapports carbone-azote; échantillons d'eau interstitielle; géologie de l'environnement; géochimie
ProgrammeAquifer Assessment & support to mapping, Géoscience des eaux souterraines
Résumé(disponible en anglais seulement)
Nitroglycerin (NG) and nitrocellulose (NC) are constituents of double-base propellants used notably for firing anti-tank ammunitions. Nitroglycerin was detected in soil and water samples from the unsaturated zone (pore water) at an active anti-tank firing position, where the presence of high nitrate (NO3-) concentrations suggests that natural attenuation of NG is occurring. However, concentrations alone cannot assess if NG is the source of NO3-, nor can they determine which degradation processes are involved. To address this issue, isotopic ratios (d15N, d18O) were measured for NO3- produced from NG and NC through various controlled degradation processes, and compared with ratios measured in field pore water samples. Results indicate that propellant combustion, and degradation mediated by soil organic carbon, produced the observed NO3- in pore water at this site. Moreover, isotopic results are presented for NO3- produced through photolysis of propellant constituents, which could be a dominant process at other sites. The isotopic data presented here constitute novel information regarding a source of NO3- that was practically not documented before, and a basis to study the contamination by energetic materials in different contexts.