Petroleum Microbiology Research Group, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Canada AB T2N 1N4.
Chemosphere. 2010 Oct;81(5):663-8. doi: 10.1016/j.chemosphere.2010.07.058. Epub 2010 Aug 21.
Oil sands tailings ponds contain a variety of anaerobic microbes, including methanogens, sulfate- and nitrate-reducing bacteria. Methanogenic activity in samples from a tailings pond and its input streams was higher with trimethylamine (TMA) than with acetate. Methanogens closely affiliated to Methanomethylovorans hollandica were found in the TMA enrichments. Tailings sedimentation increased with methanogenic activity, irrespective whether TMA or acetate was used to stimulate methanogenesis. Increased sedimentation of autoclaved tailings was observed with added pure cultures under methanogenic, as well as under nitrate-reducing conditions, but not under sulfate-reducing conditions. Scanning electron microscopy and energy-dispersive X-ray spectroscopy indicated the presence of microbes and of extracellular polymeric substances in tailings particle aggregates, especially under methanogenic and nitrate-reducing conditions. Hence different classes of microorganisms growing in tailings ponds contribute to increased tailings aggregation and sedimentation. Because addition of nitrate is known to lower methane production by methanogenic consortia, these observations offer the potential to combine lower methane emissions with improved microbially-induced tailings sedimentation.
油砂尾矿池中含有各种厌氧微生物，包括产甲烷菌、硫酸盐还原菌和硝酸盐还原菌。与乙酸盐相比，来自尾矿池及其输入流的样品中的三甲基胺 (TMA) 具有更高的产甲烷活性。在 TMA 富集物中发现了与 Methanomethylovorans hollandica 密切相关的产甲烷菌。无论使用 TMA 还是乙酸盐来刺激产甲烷作用，产甲烷活性都会增加尾矿的沉降。在添加纯培养物的情况下，在产甲烷和硝酸盐还原条件下观察到灭菌尾矿的沉降增加，但在硫酸盐还原条件下没有观察到。扫描电子显微镜和能量色散 X 射线光谱分析表明，微生物和胞外聚合物物质存在于尾矿颗粒聚集体中，尤其是在产甲烷和硝酸盐还原条件下。因此，在尾矿池中生长的不同类别的微生物有助于增加尾矿的聚集和沉降。由于已知添加硝酸盐会降低产甲烷菌的甲烷产量，因此这些观察结果为将甲烷排放量降低与微生物诱导的尾矿沉降改善结合提供了潜力。
