Description: Das Projekt "Kontinuierliche Bestimmung von N2O Isotopomeren in Umgebungsluft mittels Quantenkaskadenlaser-Absorptionspektrometrie" wird vom Umweltbundesamt gefördert und von Eidgenössische Materialprüfungs- und Forschungsanstalt, Abteilung Luftfremdstoffe,Umwelttechnik durchgeführt. Nitrous oxide (N2O) is a stratospheric ozone depleting substance and one of the four most important greenhouse gases. Its major sink, stratospheric destruction, is well quantified, but the global budget is rather uncertain due to a limited understanding of the dominant N2O sources. The study of the three main stable isotopes (14N15N16O / 15N14N16O / 14N14N16O) is a powerful way to trace the biogeochemical cycle of N2O. Absorption spectroscopy in the mid-infrared is potentially the most powerful, direct method to distinguish between all relevant N2O isotopes because of their characteristic rotational-vibrational transitions. It allows the determination of both the N2O concentration and the isotope ratios (d15Na and d15Nb). However, up to now isotope measurements with the required precision of less than 1 per mille for d15N were only possible at N2O concentration levels that are too high for environmental or atmospheric applications. Based on our latest improvements in laser spectroscopy, we expect a precision for d15N of 0.1 percent at 90 ppm of N2O in a compact and field-deployable quantum cascade laser isotope spectrometer (QCL-IS). While this is adequate to study many biological and technical processes, we also intend to develop a liquid nitrogen-free, fully-automated preconcentration unit. This unit will then be coupled to the QCL-IS to allow continuous ambient air measurements (ca. 320 ppb N2O) with a time resolution of 15 minutes. Studies based on the concentration of individual N2O isotopes and their ratio could significantly enhance our understanding of the global N2O budget. The key to this is source characterization, allocation and quantification of important processes, e.g. soil nitrification/denitrification, waste water treatment and combustion, which will become more accessible because of the novel analytical tool. Furthermore, the preconcentration unit and its coupling to QCLAS is a technique with a wide potential, since it might be used for other trace gases or isotopes with concentrations that are too low for currently available spectroscopy.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Denitrifikation ? Stratosphärisches Ozon ? Ozon ? Tierhaltungsanlage ? Biopharmazeutikum ? Resorption ? Biogeochemie ? Laser ? Laserspektroskopie ? Nitrifikation ? Skigebiet ? Spurengas ? Brunnen ? Main ? Außenluft ? Konzentrationswert ? Ozonabbauende Substanzen ? Absorption ? Abwasserbehandlung ? Lachgas ? Isotopentechnik ? Spektralanalyse ? Verbrennung ? Luft ? Gasförmiger Stoff ? Flüssiger Stoff ? Ackerland ? Isotop ? Studie ? Technik ? Umwelttechnik ? Verdichtung ? Luftschadstoff ? Boden ? Messung ? Bauelement ? Forschungseinrichtung ? Umwelt ? Globale Aspekte ? Treibhausgas ? Chemischer Stoff ? FREI ? Stall ? GEKOPPELT ? VERARBEITEN ? VERFUEGBAR ? VERTEILUNG ? Verwertung ? BESCHREIBUNG ? WICHTIG ? Kaskade [Verfahrenstechnik] ? Kontinuierliches Verfahren ? Werkzeug ? ZERSTOERUNG ? quantum cascade laser ? BUDGET ? ANALYTISCH ? EIN ? EINGESCHRAENKT ? ERFASSUNG ? Konzentrat ? METHODE ? AUSGEWAEHLT ? GEBRAUCHT ? NEU ? POTENZIAL ? SONSTIG ? stable isotopes ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2009-11-01 - 2011-10-31
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