Enhancing the Treatment of Oil Sands Process Water through Bioremediation

加拿大艾伯塔省的油砂行业目前每天生产100多万桶石油，而该地区的沥青储量估计为1740亿桶。这些沥青矿藏不容易获得，必须用大量热水开采。这反过来又导致了大量的废物，表现为油砂、受工艺影响的水和尾矿。艾伯塔省政府制定了零排放政策，要求这些材料在现场回收或储存，并要求运营商随着时间的推移将受影响的地点恢复到以前的自我维持的生态系统。一种就地储存和处理的选择是尾矿湖，它由覆盖着一层水的流体细尾矿组成。据预测，随着时间的推移，池塘中存在的污染物将经历自然衰减。然而，利用尾坑湖泊作为一种成功的填海选择尚未在全野外范围内得到证明，人们仍然担心化学品从沉积物向上覆盖水的流动以及微生物介导的生物地球化学反应的影响。 存在臭氧等化学修复选择，但成本太高，无法大规模使用。我们实验室最近的工作表明，在受油砂工艺影响的水中添加萃取工艺废品(石油焦)，有望成为一种廉价的有效吸附污染物的方法。然而，众所周知，石油焦在与受油砂工艺影响的水接触时会渗出无机化合物(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。 该发现计划的主要目标是：1)调查尾井湖泊中发生的生物地球化学反应；2)确定能够在尾井湖泊封闭之前或期间降解污染物并加强修复受油砂工艺影响的水的微生物群体或个体(S)。这项研究的短期成果将包括：1)提高对末端坑湖泊内污染物的通量和生物地球化学的了解；2)评估本地微生物群落和孤立的生物体降解令人担忧的污染物的能力；3)评价在封闭末端坑湖泊之前使用石油焦结合钒的生物修复有效处理受油砂工艺影响的水的可行性。从长远来看，这项研究将增进我们对自然生物修复过程的了解，并为我们提供监测和提高填海活动的有效性和时间表的工具。

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.