Thermochemical nitrate reduction [electronic resource]
A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techni...
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Online Access |
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| Corporate Authors: | , |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Dept. of Defense ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1992.
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| Subjects: |
| Summary: | A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techniques must be considered before permanent disposal operations begin. For the thermochemical reduction experiments, six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with ∼3 wt% NO₃⁻ solutions in a buffered aqueous solution at high pH (13); ammonia and formate were also mixed at low pH (4). Reactions were conducted in an aqueous solution in a batch reactor at temperatures of 200°C to 350°C and pressures of 600 to 2800 psig. Both gas and liquid samples were analyzed. The specific components analyzed were nitrate, nitrite, nitrous oxide, nitrogen, and ammonia. Results of experimental runs showed the following order of nitrate reduction of the six reducing agents in basic solution: formate > glucose > urea > hydrogen > ammonia ≈ methane. Airnmonia was more effective under acidic conditions than basic conditions. Formate was also effective under acidic conditions. A more thorough, fundamental study appears warranted to provide additional data on the mechanism of nitrate reduction. Furthermore, an expanded data base and engineering feasibility study could be used to evaluate conversion conditions for promising reducing agents in more detail and identify new reducing agents with improved performance characteristics. |
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| Item Description: | Published through the Information Bridge: DOE Scientific and Technical Information. 09/01/1992. "pnl-8226" "DE92041356" Cox, J.L.; Hallen, R.T.; Lilga, M.A. |
| Physical Description: | Pages: (42 p) : digital, PDF file. |