sup 15 N isotope biogeochemistry and natural denitrification process in groundwater: Application to the chalk aquifer of norther France

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90010-5· OSTI ID:5283508

Mariotti, A; Simon, B ^[1]; Landreau, A ^[2]

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1. Universite Pierre et Marie Curie-INRA, Paris (France)
2. BRGM Service Geologique National, Orleans (France)

The use of {sup 15}N natural isotope tracing in an aquifer contained within chalk rocks in northern France indicates that, under certain hydrogeological conditions, major denitrification occurs. At the boundary where the aquifer becomes confined, the nitrate concentrations decrease in the direction of groundwater flow accompanied by an exponential increase in {sup 15}N (expressed in {delta}{sup 15}N) of the residual nitrate. This is characteristic of kinetic isotope effects, which accompany the reduction of the nitrate ion during denitrification. Hydrogeochemical and bacteriological observations confirm this process. Natural isotope tracing also permits this process to be distinguished from local dilution with nitrate-free water, which would entail a major drop in nitrate values without {sup 15}N isotopic enrichment. A model is proposed to explain the relatively small observed magnitude of the isotopic fractionation effect.

• OSTI ID: 5283508
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 52:7; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540311* -- Environment
Aquatic-- Basic Studies-- Radiometric Techniques-- (1990-)
58 GEOSCIENCES
580000 -- Geosciences
AQUIFERS
BIOGEOCHEMISTRY
CARBONATE ROCKS
CHEMICAL REACTIONS
CHEMISTRY
DENITRIFICATION
EUROPE
FRANCE
GEOCHEMISTRY
GROUND WATER
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPE RATIO
ISOTOPES
KINETICS
LIGHT NUCLEI
LIMESTONE
MANAGEMENT
NITRATES
NITROGEN 15
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PROCESSING
REACTION KINETICS
ROCKS
SEDIMENTARY ROCKS
STABLE ISOTOPES
TRACER TECHNIQUES
WASTE MANAGEMENT
WASTE PROCESSING
WATER
WESTERN EUROPE