TY - JOUR
T1 - Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils
AU - Aleer, Sam
AU - Adetutu, Eric M.
AU - Weber, John
AU - Ball, Andrew S.
AU - Juhasz, Albert L.
N1 - Funding Information:
This research was funded by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (Grant number 6-5-01). The authors would like to acknowledge the support of the Centre for Environmental Risk Assessment and Remediation, University of South Australia and the School of Biological Sciences, Flinders University .
PY - 2014/4/1
Y1 - 2014/4/1
N2 - 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.
AB - 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.
KW - C-benzene mineralisation
KW - In situ bioremediation
KW - Spatial heterogeneity
UR - http://www.scopus.com/inward/record.url?scp=84894182295&partnerID=8YFLogxK
U2 - 10.1016/j.jenvman.2014.01.031
DO - 10.1016/j.jenvman.2014.01.031
M3 - Article
C2 - 24553295
AN - SCOPUS:84894182295
SN - 0301-4797
VL - 136
SP - 27
EP - 36
JO - Journal of Environmental Management
JF - Journal of Environmental Management
ER -