Real-time methods to monitor stable isotope ratios of CO_2 are needed to identify biogeochemical origins of CO_2 emissions from the soil–air interface. An isotope ratio infra-red spectrometer（IRIS） has been develop...Real-time methods to monitor stable isotope ratios of CO_2 are needed to identify biogeochemical origins of CO_2 emissions from the soil–air interface. An isotope ratio infra-red spectrometer（IRIS） has been developed to measure CO_2 mixing ratio with δ~13C isotopic signature, in addition to mixing ratios of other greenhouse gases（CH_4, N2_O）. The original aspects of the instrument as well as its precision and accuracy for the determination of the isotopic signature δ~13C of CO_2 are discussed. A first application to biodegradation of hydrocarbons is presented, tested on a hydrocarbon contaminated site under aerobic bio-treatment. CO_2 flux measurements using closed chamber method is combined with the determination of the isotopic signature δ~13C of the CO_2 emission to propose a non-intrusive method to monitor in situ biodegradation of hydrocarbons. In the contaminated area, high CO_2 emissions have been measured with an isotopic signature δ~13C suggesting that CO_2 comes from petroleum hydrocarbon biodegradation.This first field implementation shows that rapid and accurate measurement of isotopic signature of CO_2 emissions is particularly useful in assessing the contribution of contaminant degradation to the measured CO_2 efflux and is promising as a monitoring tool for aerobic bio-treatment.展开更多
基金ECOTECH BIOPHY (Optimisation de procédés de BIOdépollution des eaux souterraines contaminées par des hydrocarbures par un monitoring géo PHYsique et analyse de gaz en ligne) (ANR-10-ECOT-014)LABEX VOLTAIRE (LABoratoire d'EXcellence VOLatils-Terre,Atmosphère et Interactions - Ressources et Environnement) (ANR-10-LABX-100-01)supported by the AMIS (FAte and IMpact of Atmospher Ic Pollutant S) project funded by the European Union,under the Marie Curie Actions IRSES (International Research Staff Exchange Scheme),within the Seventh Framework Programme FP7-PEOPLE-2011-IRSES
文摘Real-time methods to monitor stable isotope ratios of CO_2 are needed to identify biogeochemical origins of CO_2 emissions from the soil–air interface. An isotope ratio infra-red spectrometer（IRIS） has been developed to measure CO_2 mixing ratio with δ~13C isotopic signature, in addition to mixing ratios of other greenhouse gases（CH_4, N2_O）. The original aspects of the instrument as well as its precision and accuracy for the determination of the isotopic signature δ~13C of CO_2 are discussed. A first application to biodegradation of hydrocarbons is presented, tested on a hydrocarbon contaminated site under aerobic bio-treatment. CO_2 flux measurements using closed chamber method is combined with the determination of the isotopic signature δ~13C of the CO_2 emission to propose a non-intrusive method to monitor in situ biodegradation of hydrocarbons. In the contaminated area, high CO_2 emissions have been measured with an isotopic signature δ~13C suggesting that CO_2 comes from petroleum hydrocarbon biodegradation.This first field implementation shows that rapid and accurate measurement of isotopic signature of CO_2 emissions is particularly useful in assessing the contribution of contaminant degradation to the measured CO_2 efflux and is promising as a monitoring tool for aerobic bio-treatment.
