Enhancing the Treatment of Oil Sands Process Water through Bioremediation

加拿大阿尔伯塔的油砂工业目前每天生产超过100万桶石油，从该地区估计的1740亿桶沥青储量中提取。这些沥青矿床不易获得，必须使用大量热水提取。这反过来又导致了大量的废物，其形式是受油砂工艺影响的水和尾矿。阿尔伯塔省政府已制定了零排放政策，要求这些材料在现场回收或储存，并要求运营商在一段时间内将受影响的场地恢复到以前的自我维持生态系统。一个现场储存和处理方案是坑底湖，它由一层水覆盖的流体细粒尾矿组成。预计池塘中的污染物将随着时间的推移而自然衰减。然而，使用坑底湖作为一个成功的填海方案尚未在整个油田规模上得到证明，关于从沉积物到上覆盖水的化学品通量和微生物介导的生物地球化学反应的影响的问题仍然存在。臭氧化等化学补救办法是存在的，但大规模使用成本太高。我们实验室最近的工作表明，将提取过程中的废物（石油焦）添加到油砂工艺影响的水中，有望成为一种有效吸附污染物的廉价方法。然而，已知石油焦在与油砂工艺影响的水接触时浸出无机化合物（如钒），这将需要后续处理。处理油砂废物的一种低成本补救选择是利用能够降解适当污染物的微生物。本发现计划的主要目标是：1）调查坑底湖中发生的生物地球化学反应; 2）在坑底湖封闭之前或期间，确定能够降解污染物并加强油砂工艺影响水的修复的微生物群落或个体生物。这项研究的短期成果将包括：（1）进一步了解坑尾湖内的污染物通量和生物地球化学;（2）评估本地微生物群落和孤立生物降解所涉污染物的能力;以及3）使用石油焦结合钒的生物修复来有效地处理油砂工艺的可行性评估-受影响的水之前，在端坑湖泊封闭。从长远来看，这项研究将提高我们对自然生物修复过程的认识，并为我们提供监测和提高复垦活动的有效性和时间轴的工具。

The oil sands industry in Alberta, Canada, currently produces over 1 million barrels of oil per day, drawing from the estimated 174 billion barrels of bitumen reserves in the area. These bitumen deposits are not readily available and must be extracted using large volumes of hot water. This in turn leads to large volumes of waste in the form of oil sands process-affected water and tailings. The Government of Alberta has instated a zero-discharge policy that requires these materials be recycled or stored on site and mandates that over time operators reclaim impacted sites back to their former self-sustaining ecosystems. One on-site storage and treatment option is end-pit lakes, which consist of fluid fine tailings capped with a layer of water. It is projected that the pollutants present in the pond will undergo natural attenuation over time. However, the use of end-pit lakes as a successful reclamation option has not yet been demonstrated at full field scale, and concerns regarding the flux of chemicals from sediments to overlying cap water and the effects of microbially mediated biogeochemical reactions remain. Chemical remediation options such as ozonation exist, but are too costly for large-scale use. Recent work in our lab has demonstrated that the addition of an extraction process waste product (petroleum coke) to oil sands process-affected water shows promise as an inexpensive way to effectively adsorb contaminants. However, petroleum coke is known to leach inorganic compounds (such as vanadium) upon contact with oil sands process-affected water, which would require subsequent treatment. One low-cost remediation option to treat oil sands waste is to utilize microorganisms that are able to degrade the appropriate contaminants. The primary objective of this Discovery Program is to 1) investigate the biogeochemical reactions occurring in end-pit lakes; and 2) identify a microbial consortium or individual organism(s) able to degrade contaminants and enhance the remediation of oil sands process-affected water prior to, or during, its enclosure in end-pit lakes. The short-term outcomes of this research will include 1) an increased understanding of contaminant flux and biogeochemistry within the end-pit lakes; 2) an assessment of the ability of the indigenous microbial community and isolated organisms to degrade contaminants of concern; and 3) an evaluation of the feasibility of using petroleum coke coupled with the bioremediation of vanadium to effectively treat oil sands process-affected water prior to enclosure in end-pit lakes. Long term, this research will enhance our knowledge of the natural bioremediation process and provide us with the tools to monitor and enhance both the effectiveness and the timeline of reclamation activities.