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| Titel |
Using 13C-labeled benzene and Raman gas spectroscopy to investigate respiration and biodegradation kinetics following soil contamination |
| VerfasserIn |
Tobias Jochum, Juergen Popp, Torsten Frosch |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126421
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| Publikation (Nr.) |
 EGU/EGU2016-6140.pdf |
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| Zusammenfassung |
| Soil and groundwater contamination with benzene can cause serious
environmental damages. However, many soil microorganisms are capable to
adapt and known to strongly control the fate of organic contamination.
Cavity enhanced Raman gas spectroscopy (CERS) was applied to investigate the
short-term response of indigenous soil bacteria to a sudden surface
contamination with benzene regarding the temporal variations of gas products
and their exchange rates with the adjacent atmosphere. $^{13}$C-labeled
benzene was spiked on a silty-loamy soil column (sampled from Hainich
National Park, Germany) in order to track and separate the changes in
heterotrophic soil respiration - involving $^{12}$CO$_{2}$ and O$_{2}$ -
from the microbial process of benzene degradation, which ultimately forms
$^{13}$CO$_{2}.$^{1}$ The respiratory quotient (RQ)
of 0.98 decreased significantly after the spiking and increased again within
33 hours to a value of 0.72. This coincided with maximum $^{13}$CO$_{2
}$concentration rates (0.63 $\mu $mol m$^{-2 }$s$^{-1})$, indicating highest
benzene degradation at 33 hours after the spiking event. The diffusion of
benzene in the headspace and the biodegradation into $^{13}$CO$_{2 }$were
simultaneously monitored and 12 days after the benzene spiking no measurable
degradation was detected anymore.$^{1}$ The RQ finally returned to a value of 0.96
demonstrating the reestablished aerobic respiration. In summary, this study
shows the potential of combining Raman gas spectroscopy and stable isotopes
to follow soil microbial biodegradation dynamics while simultaneously
monitoring the underlying respiration behavior.
Support by the Collaborative Research Center 1076 Aqua Diva is kindly
acknowledged. We thank Beate Michalzik for soil analysis and discussion.
1. T. Jochum, B. Michalzik, A. Bachmann, J. Popp and T. Frosch,
\textit{Analyst}, 2015, 140, 3143-3149. |
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