科研之友
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摘要
Microbial communities drive many biogeochemical processes in oil sands tailings and cause greenhouse gas emissions from tailings ponds. Paraffinic solvent (primarily C-5-C6; n-and iso-alkanes) is used by some oil sands companies to aid bitumen extraction from oil sands ores. Residues of unrecovered solvent escape to tailings ponds during tailings deposition and sustain microbial metabolism. To investigate biodegradation of hydrocarbons in paraffinic solvent, mature fine tailings (MFT) collected from Albian and CNRL ponds were amended with paraffinic solvent at similar to 0.1 wt% (final concentration: similar to 1000 mg L-1) and incubated under methanogenic conditions for similar to 1600 d. Albian and CNRL MFTs exhibited similar to 400 and similar to 800 d lag phases, respectively after which n-alkanes (n-pentane and n-hexane) in the solvent were preferentially metabolised to methane over iso-alkanes in both MFTs. Among iso-alkanes, only 2-methylpentane was completely biodegraded whereas 2-Methylbutane and 3-methylpentane were partially biodegraded probably through cometabdlism. 16S rRNA gene pyrosequencing showed dominance of Anaerolineaceae and Methanosaetaceae in Albian MFT and Peptococcaceae and co-domination of "Candidatus Methanoregula" and Methanosaetaceae in CNRL MFT bacterial and archaeal communities, respectively, during active biodegradation of paraffinic solvent. The results ate important for developing future strategies for tailings reclamation and management of greenhouse gas emissions.
- 出版日期2017-4-1
