N2:Ar, Nitrification and Denitrification in Southern California Borderland Basin Sediments.

摘要

The first quantitative observations of dissolved molecular nitrogen (N2) in deep-sea sedimentary pore waters show increases of up to 17% above adjacent bottom water values. The N2:Ar concentration ratio similarly increases. This increase is greater than expected from reduction of seawater nitrate in the sediment. A mechanism is suggested in which ammonia, derived from nitrogen-containing organic matter, is converted to N2 through a nitrite intermediate under conditions of low oxygen tension. Amminia is not converted to N2 in anoxic sediments that are undergoing sulfate reduction even though N2 is the thermodynamically stable species. (Author)