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| Titel |
Microbial activity and soil organic matter decay in roadside soils polluted with petroleum hydrocarbons |
| VerfasserIn |
Larysa Mykhailova, Thomas Fischer, Valentina Iurchenko |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102412
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| Publikation (Nr.) |
 EGU/EGU2015-1728.pdf |
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| Zusammenfassung |
| It has been demonstrated previously that hydrocarbon addition to soil provokes soil organic
matter priming (Zyakun et al., 2011). It has further been shown that petroleum
hydrocarbons deposit to roadside soils bound to fine mineral particles and together
with vehicle spray (Mykhailova et al., 2014), and that hydrocarbon concentrations
decrease to safe levels within the first 15 m from the road, reaching background
concentrations at 60-100 m distance (Mykhailova et al., 2013). It was the aim of this study
to (I) identify the bioavailability of different petroleum hydrocarbon fractions to
degradation and to (II) identify the native (i.e. pedogenic) C fraction affected by
hydrocarbon-mediated soil organic matter priming during decay. To address this aim, we
collected soil samples at distances from 1 to 100 m (sampling depth 15 cm) near
the Traktorostroiteley avenue and the Pushkinskaya street in Kharkov, as well as
near the country road M18 near Kharkov, Ukraine. The roads have been under
exploitation for several decades, so microbial adaptation to enhanced hydrocarbon levels
and full expression of effects could be assumed. The following C fractions were
quantified using 13C-CP/MAS-NMR: Carbohydrates, Proteins, Lignin, Aliphates,
Carbonyl/Carboxyl as well as black carbon according to Nelson and Baldock (2005).
Petroleum hydrocarbons were determind after hexane extraction using GC-MS and
divided into a light fraction (chain-length C27, Mykhailova et al., 2013). Potential soil respiration was
determined every 48 h by trapping of CO2 evolving from 20 g soil in NaOH at 20 Ë
C and at 60% of the maximum water holding capacity and titration after a total
incubation period of 4 weeks in the lab. It was found that soil respiration positively
correlated with the ratio of the light fraction to the sum of medium and heavy fractions
of petroleum hydrocarbons, which indicates higher biodegradation primarily of
the light petroleum hydrocarbon fraction. Further, soil respiration was positively
correlated with the carbohydrate fraction and negatively correlated with the aliphatic
fraction of the soil C, while carbohydrate-C and alkyl-C increased and decreased with
distance from the road, respectively. It is proposed that petroleum hydrocarbons
supress soil biological activity at concentrations above 1500 mg kg-1, and that soil
organic matter priming primarily affects the carbohydrate fraction of soil organic
matter. It can be concluded that the abundance of solid carbohydrates (O-alkyl
C) is of paramount importance for the hydrocarbon mineralization under natural
conditions, compared to more recalcitrant SOM fractions (mainly aromatic and alkyl
C).
References
Mykhailova, L., Fischer, T., Iurchenko, V. (2013) Distribution and fractional composition
of petroleum hydrocarbons in roadside soils. Applied and Environmental Soil Science, vol.
2013, Article ID 938703, 6 pages, DOI 10.1155/2013/938703
Mykhailova, L., Fischer, T., Iurchenko, V. (2014) Deposition of petroleum hydrocarbons
with sediment trapped in snow in roadside areas. Journal of Environmental Engineering and
Landscape Management 22(3):237-244, DOI 10.3846/16486897.2014.889698
Nelson P.N. and Baldock J.A. (2005) Estimating the molecular composition of a diverse
range of natural organic materials from solid-state 13C NMR and elemental analyses, 2005,
Biogeochemistry (2005) 72: 1–34, DOI 10.1007/s10533-004-0076-3
Zyakun, A., Nii-Annang, S., Franke, G., Fischer, T., Buegger, F., Dilly, O. (2011)
Microbial Actvity and 13C/12C Ratio as Evidence of N-Hexadecane and N-Hexadecanoic
Acid Biodegradation in Agricultural and Forest Soils. Geomicrobiology Journal 28:632-647,
DOI 10.1080/01490451.2010.489922 |
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