The Role of Gases in Groundwater Contamination and Remediation

气体在地下水污染和修复中的作用

• 批准号: RGPIN-2016-04803
• 负责人: Mumford, Kevin
• 金额: $ 1.97万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709474
• 关键词: Role; Gases; Groundwater; Contamination; Remediation

Groundwater is a vital natural resource. Approximately 10 million Canadians rely on groundwater as a source of drinking water. It is also an important link between surface water and deeper regional systems, and is a source of water for Canadian industries, including agriculture and oil and gas. The quality of our groundwater is threatened by contamination. There are tens of thousands of contaminated sites in Canada, many of which are brownfield properties located in urban centres and along waterfronts. The cost to clean up these sites is substantial, and likely totals tens of billions of dollars. Gases in the subsurface play an important, but often underappreciated, role in groundwater contamination. For example, gases can be created naturally or by remediation technologies, and they affect the flow of groundwater (by reducing permeability) as well as the transport and reaction of contaminants (by mass transfer between the gas and groundwater). Gases can also be contaminants themselves. For example, the rapid increase in shale gas extraction has led to increased concern over environmental impacts, including the contamination of drinking water aquifers by methane gas. The proposed research will consist of a coordinated program of laboratory experiments (bench-scale columns and flow cells) combined with numerical modelling to investigate fundamental mechanisms across multiple disciplines. A team of five graduate students (two Doctoral and three Master's) will develop methods to inject dissolved gas or create trapped gas bubbles using chemical reactions to enhance clean-up technologies. They will also investigate the dissolution of methane in groundwater to better understand the effects of gas leakage during shale gas extraction, and will develop novel characterization methods for the laboratory and field. This research will: (a) Establish the scientific basis for new technologies to enhance groundwater clean-up using thermal remediation and gas emplacement; (b) Provide the detailed data required to validate advanced numerical models of contaminant transport in groundwater where gases are present; (c) Develop new techniques for measuring groundwater gases in the laboratory (based on high-resolution visualization) and the field (based on cryogenic coring); and (d) Train graduate students to tackle emerging problems in groundwater contamination and remediation. The results of this research will be used by both researchers and industry in Canada to improve the clean-up of contaminated sites, contribute to the development of best-practices for monitoring shale gas extraction, and help site investigators more accurately measure dissolved gases and gas bubbles in groundwater. Overall, these results will support the long-term research vision of improving our understanding of gas migration and mass transfer in contaminated groundwater systems.

地下水是一种重要的自然资源。 大约有1000万加拿大人依赖地下水作为饮用水来源。 它也是地表水和深层区域系统之间的重要联系，是加拿大工业，包括农业、石油和天然气的水源。 我们的地下水质量受到污染的威胁。 加拿大有数万个受污染的场地，其中许多是位于市中心和沿着滨水地区的布朗菲尔德房产。 清理这些网站的成本是巨大的，可能总计数百亿美元。 地下气体在地下水污染中起着重要的作用，但往往被低估。 例如，气体可以自然产生或通过补救技术产生，它们影响地下水的流动（通过降低渗透性）以及污染物的运输和反应（通过气体和地下水之间的质量转移）。 气体本身也可能是污染物。 例如，页岩气开采量的迅速增加导致对环境影响的日益关切，包括甲烷气体对饮用水蓄水层的污染。 拟议的研究将包括一个协调的实验室实验计划（实验室规模的柱和流动池），结合数值建模，以研究跨多个学科的基本机制。 一个由五名研究生（两名博士生和三名硕士生）组成的小组将开发注入溶解气体或利用化学反应产生被困气泡的方法，以加强清洁技术。 他们还将研究甲烷在地下水中的溶解，以更好地了解页岩气开采过程中气体泄漏的影响，并将为实验室和现场开发新的表征方法。 这项研究将： (a)为采用热补救和天然气安置加强地下水净化的新技术奠定科学基础; (b)提供所需的详细数据，以验证存在气体的地下水中污染物迁移的先进数值模型; (c)开发在实验室（基于高分辨率可视化）和实地（基于低温取芯）测量地下水气体的新技术; (d)培训研究生解决地下水污染和补救方面的新问题。 这项研究的结果将被加拿大的研究人员和工业界用于改善污染场地的清理工作，有助于制定监测页岩气开采的最佳实践，并帮助现场调查人员更准确地测量地下水中的溶解气体和气泡。 总的来说，这些结果将支持长期的研究愿景，提高我们对污染地下水系统中气体迁移和传质的理解。