Long-term stability of dithionite in alkaline anaerobic aqueous solution

Journal Article · 10 December 2018 · Applied Geochemistry

DOI: https://doi.org/10.1016/j.apgeochem.2018.12.015 · OSTI ID:1489976

Telfeyan, Katherine  ^[1]; Migdisov, Artas A. ^[1]; Pandey, Sachin ^[1]; Vesselinov, Velimir V. ^[1]; Reimus, Paul W. ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Closed-system experiments were conducted to investigate the decomposition of sodium dithionite in aqueous solutions under varying pH and starting concentrations to simulate the deployment of dithionite as an in-situ redox barrier. Co-determination of dithionite and its degradation products was conducted using UV-Vis spectrometry, iodometric titration, and ion chromatography. In unbuffered solutions, dithionite reacted rapidly, whereas in near-neutral solutions (pH ~7), it persisted for ~ 50 days and in alkaline solution (pH ~9.5) for >100 days. As a result, these are the longest lifetimes reported to date, which we attribute to not only excluding oxygen but also preventing outgassing of H₂S.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Environmental Management (EM)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1489976
• Alternate ID(s): OSTI ID: 1636638
• Report Number(s): LA-UR--17-30396; {"Journal ID: ISSN 0883-2927",""}
• Journal Information: Applied Geochemistry, Journal Name: Applied Geochemistry Vol. 101; ISSN 0883-2927
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English