Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils

Sam Aleer, Eric M. Adetutu, John Weber, Andrew S. Ball, Albert L. Juhasz

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)

Abstract

In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (samples designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2m) was substantially different (53% dissimilar) and 2-3 fold more diverse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of 14C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF samples and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed.

Original languageEnglish
Pages (from-to)27-36
Number of pages10
JournalJournal of Environmental Management
Volume136
DOIs
Publication statusPublished or Issued - 1 Apr 2014

Keywords

  • In situ bioremediation
  • Spatial heterogeneity

ASJC Scopus subject areas

  • Waste Management and Disposal
  • Management, Monitoring, Policy and Law
  • Environmental Engineering

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