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| Titel |
Effect of petroleum products on the decomposition of soil organic matter as assessed by 13C natural abundance |
| VerfasserIn |
Wioleta Stelmach, Paweł Szarlip, Andrzej Trembaczowski, Andrzej Bieganowski |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250121855
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| Publikation (Nr.) |
 EGU/EGU2016-720.pdf |
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| Zusammenfassung |
| Petroleum products are common contaminants in soils due to human activities. They are toxic
for microorganisms and threat their functions, including decomposition of soil organic matter
(SOM). The direct estimation of altered SOM decomposition – based on the CO2
emission – is impossible after oil contamination, because oil decomposition also
contributes to the CO2 release. We used the natural differences in the isotopic signature
(δ13C) of SOM and of oil products to partition the total CO2 for both sources and to
analyze the suppression of SOM decomposition. The dynamics of 13C fractionation
during the mineralization of gasoline and diesel was measured during 42 days. The
13C fractionation varied between -8.8‰ and +3.6‰ within the first 10 days, and
stabilized thereafter at about -5.3‰ for gasoline and +3.2‰ for diesel. These 13C
fractionations and δ13C values of CO2 emitted from the soil were used for correct
partitioning of the total CO2. Contamination with gasoline reduced the CO2 efflux
from SOM decomposition by a factor of 25 (from 151 to 6 mg C-CO2 kg−1 soil
during 42 days). The negative effect of diesel was much lower: the CO2 efflux
from SOM was decreased by less than a factor of 2. The strong effect of gasoline
versus diesel reflects the lower absorption of gasoline to mineral particles and the
development of a thin film on water surfaces, leading to toxicity for microorganisms. We
conclude that the small differences of 13C of SOM and of organic pollutants can be
used to partition CO2 fluxes and analyze pollutant effects on SOM decomposition. |
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