Nitrate Reduction
Synonyms
Denitrification
Definition
Nitrate reduction is the transformation of nitrate to ammonia through bacterial respiration under anaerobic conditions.
Description
Nitrate (NO3−) is transformed by bacteria in estuaries into reduced compounds (Day et al., 2012). Bacterial respiration is an oxidation-reduction reaction or redox reaction. Nitrate reduction takes place in terrestrial, estuarine, and marine environments and can be limited by nitrate availability. Much nitrate reduction occurs in estuarine bottom sediments (Kennish, 1997).
Nitrate-reducing bacteria use nitrate as an electron acceptor to anaerobically oxidize organic matter, which releases ammonia. This process begins with oxygen depletion (<0.5 mg/L), and nitrate becomes the primary oxygen source for the bacteria. Nitrate acts as a substitute source in the water column and anoxic sediments when oxygen consumption exceeds production or transportation, and sufficient levels of nitrate are available. Nitrate-reducing...
Bibliography
- Bianchi, T. S., 2007. Biogeochemistry of Estuaries. Oxford: Oxford University Press.Google Scholar
- Day, J. W., Kemp, M. W., Yánez-Arancibia, A., and Crump, B. C., 2012. Estuarine Ecology, 2nd edn. Hoboken: Wiley-Blackwell.CrossRefGoogle Scholar
- Kennish, M. J., 1997. Practical Handbook of Estuarine and Marine Pollution. Boca Raton: CRC Press.Google Scholar