Laboratory studies investigating chemical flux across tailings-cap water zones, simulating an End Pit Lake in the Athabasca oil sands region

实验室研究调查尾矿盖水区的化学通量，模拟阿萨巴斯卡油砂地区的 End Pit Lake

• 批准号: 476652-2014
• 负责人: Ulrich, Ania
• 金额: $ 13.78万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=619249
• 关键词: Laboratory; studies; investigating; chemical; flux

The economic opportunities associated with expanded oil sands operations in the Athabasca region are substantial, but so too are the by-products of the bitumen extraction process. Of particular environmental importance in the context of landscape remediation is tailings management, more specifically the possibility of using closed mine pits as tailings repository basins. In order for these so-called end-pit lakes (EPLs) to represent an acceptable disposal alternative, tailings must be capped with a fresh water layer that, over time, develops into a self-sustaining ecosystem. Indeed ecosystem maturation is expected to occur simultaneously with tailings dewatering so that EPLs become a natural component of the boreal forest.It is useful to understand biogeochemical processes governing partitioning of contaminants in tailings and identify contaminant transport pathways to cap water. Modulating contaminant release and transport is the overall objective of the present multidisciplinary proposal. Research objectives will be met by considering two different types of laboratory experiments: (i) large volume kinetic tests conducted at elevated temperatures to accelerate processes that evolve slowly in-situ, and, (ii) small volume tests that will more specifically probe the fundamental aspects of chemical partitioning. In the former case, our analysis will include a sequencing of key microbes and a chemical characterization of clay minerals, expressed porewater and cap water. In the latter case, attention will be focused on nutrient limitation, detritus and cap water dilution effects. We also propose to separately investigate those factors (wind stress, etc.) that lead to mixing between the fluid fine tailings and cap water layers. Throughout, results will be communicated with our industrial partner and with affiliated research groups for purposes of maximizing the impact of our findings and recommendations.

与阿萨巴斯卡地区扩大油砂业务相关的经济机会是巨大的，但沥青提取过程的副产品也是如此。在景观补救方面，尾矿管理对环境特别重要，更具体地说，可能利用封闭的矿井作为尾矿存放盆地。为了使这些所谓的坑底湖（EPLs）成为一种可接受的处置替代方案，尾矿必须覆盖一层淡水层，随着时间的推移，发展成为一个自我维持的生态系统。实际上，生态系统的成熟预计将与尾矿脱水同时发生，因此EPLs成为北方森林的自然组成部分。了解尾矿中污染物分配的地球化学过程并确定污染物传输途径以覆盖水是有用的。控制污染物的释放和迁移是本多学科提案的总体目标。研究目标将通过考虑两种不同类型的实验室实验来实现：（一）在高温下进行的大体积动力学测试，以加速原位缓慢演变的过程，以及（二）小体积测试，将更具体地探测化学分区的基本方面。在前一种情况下，我们的分析将包括关键微生物的测序和粘土矿物的化学表征，表达孔隙水和盖层水。在后一种情况下，注意力将集中在营养限制，碎屑和盖水稀释效应。我们还建议单独调查这些因素（风应力等）。这导致流体细粒尾矿和盖水层之间的混合。在整个过程中，结果将与我们的工业合作伙伴和附属研究小组进行沟通，以最大限度地发挥我们的调查结果和建议的影响。