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Wyszukujesz frazę "nitrogen isotope" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Comparison of two methods for the determination of nitrogen and oxygen isotope composition of dissolved nitrates
Autorzy:
Chmura, W. M.
Różański, K.
Kuc, T.
Gorczyca, Z.
Powiązania:
https://bibliotekanauki.pl/articles/146460.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
nitrates
isotope composition
denitrification
nitrogen-15
oxygen-18
Opis:
Two methods of sample preparation for isotopic analyses of nitrates dissolved in water are presented: (i) chemical conversion of NO3– to N2 and CO2, and (ii) bacterial reduction of NO3– to N2O, followed by the measurement of nitrogen and oxygen isotope composition of these gases. Both methods have been successfully used for routine isotope analyses of dissolved nitrates in different types of water. The chemical conversion method, requiring ca. 300 mi mol of NO3– yields relatively good precision, in the order of 0.3‰ for delta15N, and 0.6‰ for delta18 O. The bacterial reduction method was modified in this study to accommodate samples of intermediate size (ca. 30 mmol of NO3–) to provide sufficient amount of N2O gas for isotope analysis using conventional IRMS. The method demonstrated satisfactory results, although sample preparation was more complicated and required access to microbiological laboratory.
Źródło:
Nukleonika; 2009, 54, 1; 17-23
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of denitrification rates in fissured-karstic aquifer near Opole (south-west Poland): combined use of gaseous and isotope tracers
Autorzy:
Żurek, A.
Różański, K.
Mochalski, P.
Kuc, T.
Powiązania:
https://bibliotekanauki.pl/articles/2062983.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
excess nitrogen
isotope composition of nitrate
denitrification
fissured-karstic aquifer
Opis:
Denitrification is the only process leading to reduction of nitrate concentration in groundwater. In this paper the authors report the results of combined measurements of excess gaseous nitrogen and 18O and 15N isotope composition of dissolved nitrate in fissured-karstic Triassic aquifer located in southwestern Poland, in the vicinity of Opole. Generally, the wells located in the confined part of the aquifer reveal greatly reduced nitrate content (ca. 0.3 and 2.7 mg NO3/dm3). Such decrease of nitrate content together with δ18O and δ15N data for those wells suggest well-advanced denitrification process. Enrichment in 15N and 18O of the remaining nitrate corresponds to initial nitrate content in the order of 1.5 to 12 mg NO3/dm3. Lack of tritium in those wells suggest the pre-bomb age of water and natural range of initial nitrate content. In majority of the measured wells nitrogen excess has been below the detection limit of ca. 3.5 mg NO3/dm3. This method is not sensitive enough to detect denitrification of natural nitrate which concentrations in groundwater in the study area were generally below 10 mg NO3/dm3. The presented study demonstrated that combining isotope analyses of nitrates with tritium or other transient tracers may provide additional insights into the dynamics of water and nitrate transformation in groundwater systems.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2010, 441 Hydrogeologia z. 10; 209--216
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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