Oil sands surface mining in Alberta has generated over a billion cubic metres of waste, known as tailings, consisting of sands, silts, clays, and process-affected water that contains toxic organic compounds and chemical constituents. All of these tailings will eventually be reclaimed and integrated into one of two types of mine closure landforms: end pit lakes (EPLs) or terrestrial landforms with a wetland feature. In EPLs, tailings deposits are capped with several metres of water while in terrestrial landforms, tailings are capped with solid materials, such as sand or overburden. Because tailings landforms are relatively new, past research has heavily focused on the geotechnical and biogeochemical characteristics of tailings in temporary storage ponds, referred to as tailings ponds. As such, the geochemical stability of tailings landforms remains largely unknown. This review discusses five mechanisms of geochemical change expected in tailings landforms: consolidation, chemical mass loading via pore water fluxes, biogeochemical cycling, polymer degradation, and surface water and groundwater interactions. Key considerations and knowledge gaps with regard to the long-term geochemical stability of tailings landforms are identified, including salt fluxes and subsequent water quality, bioremediation and biogenic greenhouse gas emissions, and the biogeochemical implications of various tailings treatment methods meant to improve geotechnical properties of tailings, such as flocculant (polyacrylamide) and coagulant (gypsum) addition.

中文翻译：

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闭矿地貌中油砂尾矿的地球化学稳定性

艾伯塔省的油砂露天开采产生了超过 10 亿立方米的废物，称为尾矿，由沙子、淤泥、粘土和含有有毒有机化合物和化学成分的受加工影响的水组成。所有这些尾矿最终都将被回收并整合到两种类型的矿山关闭地貌中的一种：端坑湖 (EPL) 或具有湿地特征的陆地地貌。在 EPL 中，尾矿沉积物被几米深的水覆盖，而在陆地地形中，尾矿被固体物质覆盖，例如沙子或覆盖层。由于尾矿地貌相对较新，过去的研究主要集中在临时储存池中尾矿的岩土工程和生物地球化学特征，简称尾矿池。像这样，尾矿地貌的地球化学稳定性在很大程度上仍然未知。本综述讨论了尾矿地貌中预期的地球化学变化的五种机制：固结、通过孔隙水通量的化学物质负荷、生物地球化学循环、聚合物降解以及地表水和地下水相互作用。确定了与尾矿地貌长期地球化学稳定性相关的关键考虑因素和知识差距，包括盐通量和随后的水质、生物修复和生物温室气体排放，以及旨在改善尾矿岩土特性的各种尾矿处理方法的生物地球化学影响尾矿，如絮凝剂（聚丙烯酰胺）和混凝剂（石膏）添加。固结、通过孔隙水通量的化学物质负荷、生物地球化学循环、聚合物降解以及地表水和地下水相互作用。确定了与尾矿地貌的长期地球化学稳定性有关的关键考虑因素和知识差距，包括盐通量和随后的水质、生物修复和生物温室气体排放，以及旨在改善尾矿岩土特性的各种尾矿处理方法的生物地球化学影响尾矿，如絮凝剂（聚丙烯酰胺）和混凝剂（石膏）添加。固结、通过孔隙水通量的化学物质负荷、生物地球化学循环、聚合物降解以及地表水和地下水相互作用。确定了与尾矿地貌长期地球化学稳定性相关的关键考虑因素和知识差距，包括盐通量和随后的水质、生物修复和生物温室气体排放，以及旨在改善尾矿岩土特性的各种尾矿处理方法的生物地球化学影响尾矿，如絮凝剂（聚丙烯酰胺）和混凝剂（石膏）添加。