Denitrification in coastal marine sediments

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5608506

Slater, J M

Acetylene inhibition of nitrous oxide reduction in saltmarsh sediment slurry was only temporary. The reduction was unaffected by initial nitrate concentration (16-200 {mu}M), gas-phase acetylene concentration (10-100%), or sulfide. In more dilute slurries and in estuarine sediment nitrous oxide persisted in the presence of acetylene, unless carbon was added. The rate of nitrous oxide disappearance was apparently linked to development of very low nitrate concentrations. In saltmarsh sediment slurries, Cr(Vl), Pb, Zn, Cu, and Mo(Vl) at 100 ug/g all caused initial inhibition and subsequent increase in denitrification; Ni decreased both initial rate and final production of nitrous oxide. Lower levels of Ni had effects intermediate between 1000 ug/g and controls. Nitrous oxide production was inhibited by 1000 ug/g lindane, phenanthrene, toxaphene, naphthalene, and pentachlorophenol and stimulated slightly by Aroclor 1254. In enrichment cultures of denitrifying bacteria from saltmarsh sediment, all the nitrate-N supplied appeared and persisted as nitrous oxide in the presence of acetylene. Ni at 1, 10, and 100 uM and Cr(Vl) at 100 {mu}M inhibited denitrification rates by 17, 29 ({plus minus}13), 78, and 38% respectively. The effect of nitrate added by submarine discharge of groundwater to estuarine sediment was noticeable. Denitrification was consistently measured at 40 cm depth along 30 km of shoreline at rates of 0.14-2.8 ng-at N/g/d; it decreased with distance offshore and where groundwater input was least. The denitrification was apparently limited by carbon, not nitrate. High rates of denitrification were measured in the aquifer (17 ng-at N/g/d). The denitrification was enough to remove 46% of the observed nitrate decrease between 40 and 14 cm depth in the sediment.

• Research Organization: State Univ. of New York, Stony Brook, NY (USA)
• OSTI ID: 5608506
• Country of Publication: United States
• Language: English

Related Subjects

520100* -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACETYLENE
ALKYNES
BACTERIA
BIOCHEMICAL REACTION KINETICS
CARBON
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM
COPPER
DENITRIFICATION
DEPTH
DIMENSIONS
ELEMENTS
ESTUARIES
GROUND WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
INHIBITION
KINETICS
LEAD
METALS
MICROORGANISMS
MOLYBDENUM
NICKEL
NITRATES
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
OFFSHORE SITES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
QUANTITY RATIO
REACTION KINETICS
RECHARGE
REDUCTION
SEDIMENTS
SULFIDES
SULFUR COMPOUNDS
SURFACE WATERS
TRANSITION ELEMENTS
WATER
ZINC