Titre :
|
Factors affecting denitrification during infiltration of river water into a sand and gravel aquifer in Saxony, Germany
|
Auteurs :
|
T. Grischek ;
K. Hiscock ;
T. Metschies ;
AL Et
|
Type de document :
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article/chapitre/communication
|
Année de publication :
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1998
|
Format :
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p. 450-460
|
Langues:
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= Anglais
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Catégories :
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EAU
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Mots-clés:
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ELBE COURS D'EAU
;
COURS D'EAU
;
INFILTRATION
;
DENITRIFICATION
;
ISOTOPE
;
AZOTE
;
NITRATE
|
Résumé :
|
River infiltration into a sand and gravel aquifer was investigated to assess the importance of dentrification in maintaining low-NO3- groundwater supplies. Samples from the River Elbe and groundwater sampling points along a section of the aquifer were analysed for dissolved organic carbon, major ions and the N-15/N-14 isotopic ratio of dissolved NO3-. Input of NO3- to the aquifer is influenced by seasonal, temperature-dependent denitrification in the river bed sediments. Along an upper flowpath in the aquifer from the River Elbe to a sampling point at a distance of 55 m, the median NO3- concentration decreased by 4.8 mg litre(-1) and the delta(15)N composition increased by + 9.0%, consistent with denitrification. Similar isotopic enrichment was demonstrated in a laboratory column experiment with a reduction in NO3- of 10.5 mg litre(-1) for an increase in delta(15)N of + 9.8%, yielding an isotopic enrichment factor of -14.6%.
|
Source :
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Water Research, vol.32, n°2
|