Coupling of physical and bio-geochemical processes in saturated and unsaturated subsurface systems.

饱和和不饱和地下系统中物理和生物地球化学过程的耦合。

• 批准号: RGPIN-2014-06610
• 负责人: Amos, Richard
• 金额: $ 2.7万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 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=634171
• 关键词: Coupling; physical; bio; geochemical; processes

The contamination of groundwater from mining, industrial and other anthropogenic activities threatens potable water supplies and ecosystem health. The transport and fate of contaminants in groundwater and in unsaturated soils often involves complex biogeochemical reactions coupled to physical transport and attenuation processes. Reactive transport models provide a means of quantifying these processes, providing a means of analyzing complex data sets and providing insights into the underlying mechanisms of contaminant transport and attenuation. The long-term objectives of the research are to better understand and quantify coupled biogeochemical and physical processes, and the effect of this coupling on contaminant transport and attenuation, through the development of reactive transport models. The key areas for development will include:1) Simulation of nano-particle and colloid transport and reactivity: Colloids are particles with dimensions measuring in the nano-meter scale. Inorganic and organic colloids can interact with metal-bearing wastes and potentially facilitate their transport in the environment. A reactive transport model will be developed to simulate colloid transport and geochemical interactions, and the model will be used to simulate field and laboratory column experiments to gain a better understanding of colloid-associated metal transport.2) Simulation of stable isotope fractionation in multi-phase systems: A reactive transport model will be developed to simulate the fractionation of carbon isotopes in methane and carbon in dissolved and vapour phase gases, including gas bubbles. The model will be used to simulate the degradation of contaminants at an oil spill site near the town of Bemidji, MN, providing a better understanding of degradation rates, and transport and attenuation mechanisms. In addition, laboratory tank experiments will be conducted to better quantify the gas/water interactions at the water table.3) Coupling of physical and geochemical processes in mine waste: The prediction of drainage quality from waste-rock piles is an important aspect of mine planning and permitting. A reactive transport model will be developed to couple thermal, hydrological and geochemical interactions in waste-rock dumps. The model will be applied to data collected at the Diavik Diamond Mine in the Northwest Territories to better understand the processes controlling water quality.4) Mechanistic simulation of gases and gas bubble movement in contaminated aquifers. A reactive transport model will be developed to provide a better description of gas transport, including the movement of gas bubbles in groundwater. The model will be used to simulate 1) the transport of volatile organic contaminants in groundwater including the vertical transport of gas bubbles due to buoyancy, 2) tritium and organic contaminants in unsaturated materials below and low-level nuclear waste repository, and 3) the entrapment of gas bubbled during recharge below an artificial recharge pond.The proposed research will provide a unique reactive transport model that will provide insight into the movement of contaminants in the subsurface. This insight will aid in the development of cost-effective contaminant stabilization and remediation options that will assist Canadian industry in meeting environmental protection standards. The research will train highly qualified personnel in the development and application of numerical models and provide them with a thorough understanding of contaminant geochemistry and remediation science. These trainees will continue with cutting edge research or will work in industry, managing contamination issues and helping to maintain Canadian companies at the leading edge of the contaminant remediation industry.

采矿、工业和其他人为活动造成的地下水污染威胁着饮用水供应和生态系统健康。地下水和非饱和土壤中污染物的迁移和归宿通常涉及复杂的生物地球化学反应以及物理迁移和衰减过程。反应性传输模型提供了一种量化这些过程的方法，提供了一种分析复杂数据集并深入了解污染物传输和衰减的潜在机制的方法。该研究的长期目标是通过开发反应传输模型，更好地理解和量化耦合的生物地球化学和物理过程，以及这种耦合对污染物传输和衰减的影响。开发的关键领域包括：1）纳米颗粒和胶体传输和反应性的模拟：胶体是尺寸在纳米级测量的颗粒。无机和有机胶体可以与含金属废物相互作用，并有可能促进它们在环境中的运输。将开发反应输运模型来模拟胶体输运和地球化学相互作用，该模型将用于模拟现场和实验室柱实验，以更好地了解胶体相关的金属输运。2）多组分稳定同位素分馏的模拟相系统：将开发反应输运模型来模拟甲烷中的碳同位素和溶解的气相气体（包括气泡）中的碳的分馏。该模型将用于模拟明尼苏达州伯米吉镇附近漏油现场污染物的降解，从而更好地了解降解率以及迁移和衰减机制。此外，还将进行实验室储罐实验，以更好地量化地下水位处的气/水相互作用。3）矿山废物中物理和地球化学过程的耦合：废石堆排水质量的预测是矿山的一个重要方面规划和许可。将开发反应传输模型来耦合废石堆中的热、水文和地球化学相互作用。该模型将应用于西北地区戴维克钻石矿收集的数据，以更好地了解控制水质的过程。4) 受污染含水层中气体和气泡运动的机械模拟。将开发反应输运模型，以更好地描述气体输运，包括地下水中气泡的运动。该模型将用于模拟 1) 地下水中挥发性有机污染物的传输，包括由于浮力引起的气泡垂直传输，2) 下方不饱和材料和低水平核废料储存库中的氚和有机污染物，以及 3)人工补给池下方补给期间气泡的截留。拟议的研究将提供独特的反应传输模型，该模型将深入了解污染物在地下的运动。这一见解将有助于开发具有成本效益的污染物稳定和修复方案，从而帮助加拿大工业达到环境保护标准。该研究将培训数值模型开发和应用方面的高素质人才，并使他们对污染物地球化学和修复科学有透彻的了解。这些学员将继续进行前沿研究或在工业界工作，管理污染问题并帮助加拿大公司保持污染物修复行业的领先地位。