Denitrification associated with stream periphyton: chamber estimates from undisrupted communities
Undisrupted periphyton communities from a N-rich (NO/sub 3//sup -/ = 63 ..mu..mol L/sup -1/) and pristine (NO/sub 3//sup -/ = 2.9 ..mu..mol L/sup -1/) stream were assayed for denitrifying activity (acetylene-blockage technique) in 40-L chambers incubated at in situ temperature and nutrient concentrations. Nitrous oxide formation associated with periphyton from the N-rich stream was immediate and linear (52.1 ..mu..mol N/sub 2/O m/sup -2/ h/sup -1/) in the dark, anaerobic chamber (50 kPa C/sub 2/H/sub 2/). In the corresponding light, aerobic chamber (50 kPa C/sub 2/H/sub 2/), N/sub 2/O production was inhibited by 82% (9.3 ..mu..mol N/sub 2/O m/sup -2/ h/sup -1/). Nitrous oxide formation was not associated with periphyton from the pristine stream incubated in situ, either with or without NO/sub 3//sup -/ amendment. Denitrification estimates made with undisrupted periphyton communities at in situ temperature and nutrient concentrations (40-L chambers) were less variable than estimates made with periphyton scraping in small flasks (room temperature). The calculated diel periphyton-associated denitrification rate based on a 14-h light-10-h dark day was 651 ..mu..mol N/sub 2/O m/sup -2/ d/sup -1/. The data suggest denitrification within periphyton mats may contribute toward removal of NO/sub 3//sup -/ from N-rich fluvial environments.
- Research Organization:
- Geological Survey, Menlo Park, CA
- OSTI ID:
- 5710426
- Journal Information:
- J. Environ. Qual.; (United States), Vol. 13:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AUFWUCHS
METABOLISM
STREAMS
DENITRIFICATION
ACETYLENE
INHIBITION
NITRATES
NITROUS OXIDE
QUALITATIVE CHEMICAL ANALYSIS
REMOVAL
ALKYNES
AQUATIC ORGANISMS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
HYDROCARBONS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SURFACE WATERS
520200* - Environment
Aquatic- Chemicals Monitoring & Transport- (-1989)
560302 - Chemicals Metabolism & Toxicology- Microorganisms- (-1987)