Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    ISSN: 1573-515X
    Schlagwort(e): adsorption ; bacterial dissimilatory sulfate reduction ; dry deposition ; forested catchment ; Lake Gårdsjön ; isotopes ; oxidation of sulfur ; sulfate ; sulfur ; Sweden
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Geologie und Paläontologie
    Notizen: Abstract A small catchment on the Swedish West Coast has been studied over four years to determine S dynamics by using S isotope ratios. A Norway spruce dominated forest covers the catchment, and small peat areas occur in the lower parts of the catchment. The runoff $$\delta ^{34} S_{SO_4 } $$ values varied both during the year, and from year to year. Over the period from February 1990 to December 1993, the $$\delta ^{34} S_{SO_4 } $$ values ranged from — 1%. to +11%. Over the same period, the throughfall $$\delta ^{34} S_{SO_4 } $$ values ranged from +1%. to +15%. There was no correlation (r 2= 0.01; Pr(F)=0.57) between $$\delta ^{34} S_{SO_4 } $$ values in throughfall and runoff. Since the only input of S to the catchment is atmospheric deposition, the long-term runoff S mass flux is controlled by the deposition. Therefore, processes in the catchment are responsible for the variation in the runoff $$\delta ^{34} S_{SO_4 } $$ values. During periods with $$\delta ^{34} S_{SO_4 } $$ enriched runoff, bacterial dissimilatory SO 4 2− reduction occurs in the catchment. After very dry periods, oxidation of this reduced S, which is32S-enriched, can be traced in runoff. Previous studies of the catchment have not been able to distinguish between: 1) oxidation of reduced S and dry deposition, and 2) reduction and adsorption. From the current study, it can be concluded that adsorption and dry deposition cannot cause the observed variation in runoff $$\delta ^{34} S_{SO_4 } $$ .
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1573-515X
    Schlagwort(e): adsorption ; bacterial dissimilatory sulfate reduction ; dry deposition ; forested catchment ; Lake Gårdsjön ; isotopes ; oxidation of sulfur ; sulfate ; sulfur ; Sweden
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Geologie und Paläontologie
    Notizen: Abstract A small catchment on the Swedish West Coast has been studied over four years to determine S dynamics by using S isotope ratios. A Norway spruce dominated forest covers the catchment, and small peat areas occur in the lower parts of the catchment. The runoff δ34SSO4 values varied both during the year, and from year to year. Over the period from February 1990 to December 1993, the δ34SSO4 values ranged from −1‰ to +11‰. Over the same period, the throughfall δ34SSO4 values ranged from +1‰ to +15‰. There was no correlation (r2 = 0.01; Pr(F) = 0.57) between δ34SSO4 values in throughfall and runoff. Since the only input of S to the catchment is atmospheric deposition, the long-term runoff S mass flux is controlled by the deposition. Therefore, processes in the catchment are responsible for the variation in the runoff δ34SSO4 values. During periods with 34SSO4 enriched runoff, bacterial dissimilatory SO42- reduction occurs in the catchment. After very dry periods, oxidation of this reduced S, which is 32S-enriched, can be traced in runoff. Previous studies of the catchment have not been able to distinguish between: 1) oxidation of reduced S and dry deposition, and 2) reduction and adsorption. From the current study, it can be concluded that adsorption and dry deposition cannot cause the observed variation in runoff δ34SSO4.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Fresenius' Zeitschrift für analytische Chemie 287 (1977), S. 310-311 
    ISSN: 1618-2650
    Schlagwort(e): Isotopenanalyse von Kohlenstoff, Sauerstoff in Magnesit ; Massenspektrometrie ; Freisetzung von CO2
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary Since the application of the isotope geochemical method to obtain information on the formation mechanism of magnesite deposits was considered promising, we have developed a method to prepare carbon dioxide from magnesite samples for oxygen and carbon isotope analyses, using phosphoric acid reaction at an elevated temperature of 95° C. Data showing the reproducibility of the method (better than ±0.2‰ for both carbon and oxygen) are presented. The oxygen isotope fractionation factor between the evolved CO2 and magnesite at 95° C is 1.0080.
    Notizen: Zusammenfassung Mit dem Ziel, durch isotopen-geochemische Untersuchungen den Bildungsmechanismus von Magnesitablagerungen aufzuklären, wurde ein Verfahren zur Freisetzung von Kohlendioxid aus den Magnesitproben zur O- und C-Isotopenanalyse ausgearbeitet. Dazu dient die Reaktion mit Phosphorsäure bei 95° C. Die Reproduzierbarkeit ist besser als ±0,2‰ für beide Elemente. Der Fraktionierungsfaktor für das Sauerstoffisotop zwischen CO2 und Magnesit bei 95° C beträgt 1,0080.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...