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| Titel |
Response of soil microorganisms to radioactive oil waste: results from a leaching experiment |
| VerfasserIn |
P. Galitskaya, L. Biktasheva, A. Saveliev, S. Ratering, S. Schnell, S. Selivanovskaya |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 12 ; Nr. 12, no. 12 (2015-06-16), S.3681-3693 |
| Datensatznummer |
250117987
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| Publikation (Nr.) |
 copernicus.org/bg-12-3681-2015.pdf |
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| Zusammenfassung |
Oil wastes produced in large amounts in the processes of oil extraction,
refining, and transportation are of great environmental concern because of
their mutagenicity, toxicity, high fire hazardousness, and hydrophobicity.
About 40% of these wastes contain radionuclides; however, the effects of
oil products and radionuclides on soil microorganisms are frequently studied
separately.
The effects on various microbial parameters of raw waste containing 575 g of
total petroleum hydrocarbons (TPH) kg−1 waste, 4.4 of
226Ra, 2.8 of 232Th, and 1.3 kBq kg−1 of
40K and its treated variant (1.6 g kg−1 of TPH, 7.9
of 226Ra, 3.9 of 232Th, and 183 kBq kg−1 of
40K) were examined in a leaching column experiment to separate the
effects of hydrocarbons from those of radioactive elements. The raw waste
sample (H) was collected from tanks during cleaning and maintenance, and a
treated waste sample (R) was obtained from equipment for oil waste
treatment. Thermal steam treatment is used in the production yard to reduce
the oil content.
The disposal of H waste samples on the soil surface led to an increase in
the TPH content in soil: it became 3.5, 2.8, and 2.2 times higher in the
upper (0–20 cm), middle (20–40 cm), and lower (40–60cm) layers,
respectively.
Activity concentrations of 226Ra and 232Th increased in soil
sampled from both H- and R- columns in comparison to their concentrations in
control soil. The activity concentrations of these two elements in samples
taken from the upper and middle layers were much higher for the R-column
compared to the H-column, despite the fact that the amount of waste added to
the columns was equalized with respect to the activity concentrations of
radionuclides.
The H waste containing both TPH and radionuclides affected the functioning
of the soil microbial community, and the effect was more pronounced in the
upper layer of the column. Metabolic quotient and cellulase activity were
the most sensitive microbial parameters as their levels were changed 5–1.4
times in comparison to control ones. Changes in soil functional
characteristics caused by the treated waste containing mainly radionuclides
were not observed. PCR-SSCP (polymerase chain reaction – single strand
conformation polymorphism) analysis followed by MDS (metric multidimensional
scaling) and clustering analysis revealed that the shifts in microbial
community structure were affected by both hydrocarbons and radioactivity.
Thus, molecular methods permitted to reveal the effects on soil microbial
community not only from hydrocarbons, which significantly altered functional
characteristics of soil microbiome, but also from radioactive elements. |
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