5
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Direct evaluation of in situ biodegradation in Athabasca oil sands tailings ponds using natural abundance radiocarbon.

      1 ,

      Environmental science & technology

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Compound-specific stable (δ(13)C) and radiocarbon (Δ(14)C) isotopes of phospholipid fatty acids (PLFAs) were used to evaluate carbon sources utilized by the active microbial populations in surface sediments from Athabasca oil sands tailings ponds. Algal-specific PLFAs were absent at three of the four sites investigated, and δ(13)CPLFA values were generally within ~3‰ of that reported for oil sands bitumen (~-30‰), suggesting that the microbial communities growing on petroleum constituents were dominated by aerobic heterotrophs. Δ(14)CPLFA values ranged from -906 to -586‰ and pointed to significant uptake of fossil carbon, particularly in PLFAs (e.g., cy17:0 and cy19:0) often associated with petroleum hydrocarbon degrading bacteria. The comparatively heavier Δ(14)C values found in other, less specific PLFAs (e.g., 16:0) indicated the preferential uptake of younger organic matter by the general microbial population. Since the main carbon pools in tailings sediment were essentially "radiocarbon dead" (i.e., Δ(14)C ~ -1000‰), the principal source for this relatively modern carbon is considered to be the Athabasca River, which provides the bulk of the water used in the bitumen extraction process. The preferential utilization of the minor amount of younger and presumably more labile material present in systems otherwise dominated by petroleum carbon has important implications for remediation strategies, since it implies that organic contaminants may persist long after reclamation has begun. Alternatively, this young organic matter could play a vital and necessary role in supporting the microbial utilization of fossil carbon via cometabolism or priming processes.

          Related collections

          Author and article information

          Journal
          Environ. Sci. Technol.
          Environmental science & technology
          1520-5851
          0013-936X
          Sep 17 2013
          : 47
          : 18
          Affiliations
          [1 ] Geological Survey of Canada, Natural Resources Canada , Québec City, Québec, G1K 9A9, Canada.
          Article
          10.1021/es402302z
          23957578

          Comments

          Comment on this article