Fate of ammonium in a Gulf coast estuarine sediment

Journal Article · · J. Environ. Qual.; (United States)

OSTI ID:7025741

Smith, C J; De Laune, R D

The loss of /sup 15/N labeled (NH/sub 4/)/sub 2/SO/sub 4/ applied uniformly to estuarine sediment was investigated under laboratory conditions. The recovery of /sup 15/N labeled NH/sub 4//sup +/-N in the NH/sub 4//sup +/, NO/sub 2//sup -//sub 2/ + NO/sub 3//sup -/, and organic N pools was determined at depth within the sediment cores. Concentrations of NH/sub 4//sup +/-N generally increased with depth, with largest gradients near the surface. There was significant ammonification in underlying anaerobic sediment with a consistent increase in concentration of NH/sub 4//sup +/ being observed with increasing time of incubation. Surface sediment became depleted in /sup 15/NH/sub 4//sup +/-N with time of incubation due to nitrification. Nitrogen-15 losses occurred in the surface layer predominately from nitrification-denitrification of the NH/sub 4//sup +/. Net NH/sub 4//sup +/ incorporation into the organic N fraction (immobilization) was greater in the aerobic surface sediment than in the underlying anaerobic sediment. In contrast, after 70 d of incubation, anaerobic sediment partitioned 65 +/- 9% of the added /sup 15/N in the inorganic NH/sub 4//sup +/-N pool and 27 +/- 7% in the organic N pool. Total /sup 15/N losses increased with time of incubation and ranged from 9 to 26% following the addition of 3, 6.5, and 17 mg /sup 15/N excess kg/sup -1/ dry sediment.

• Research Organization: Louisiana State Univ., Baton Rouge
• OSTI ID: 7025741
• Journal Information: J. Environ. Qual.; (United States), Journal Name: J. Environ. Qual.; (United States) Vol. 15:3; ISSN JEVQA
• Country of Publication: United States
• Language: English

Related Subjects

520200* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROBIC CONDITIONS
AMMONIUM COMPOUNDS
AMMONIUM SULFATES
ANAEROBIC CONDITIONS
BENCH-SCALE EXPERIMENTS
CHEMICAL REACTIONS
DATA
DENITRIFICATION
ESTUARIES
EVAPORATION
EXPERIMENTAL DATA
FEDERAL REGION VI
INCUBATION
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LOUISIANA
MINERAL CYCLING
NITRIFICATION
NITROGEN 15
NITROGEN ISOTOPES
NORTH AMERICA
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SEDIMENTS
STABLE ISOTOPES
SULFATES
SULFUR COMPOUNDS
SURFACE WATERS
TRACER TECHNIQUES
USA