Advancing non-invasive geoelectrical methods for imaging soil and groundwater contaminants

推进非侵入性地电方法对土壤和地下水污染物进行成像

• 批准号: RGPIN-2020-06427
• 负责人: Power, Christopher
• 金额: $ 1.89万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749099
• 关键词: Advancing; non; invasive; geoelectrical; methods

Contamination of soil and groundwater by hazardous chemicals, including chlorinated solvents and coal tar (known as dense nonaqueous phase liquids (DNAPLs)) and other anthropogenic chemicals such as per- and polyfluoroalkyl substances (PFAS), remains a serious problem worldwide. Approximately 24,000 federal contaminated sites exist in Canada alone, including former industrial lands, decommissioned refineries, and abandoned gas stations. In 2019, the Federal Contaminated Sites Action Plan was renewed for 15 years, with the federal government pledging $1.16 billion for the first five years (2020 to 2024). Of this, $1.05 billion has been assigned to remediate contaminated sites. Successful remediation requires accurate knowledge on where the contaminants are, and how quickly they are being removed. Since conventional methods, including boreholes and monitoring wells, are intrusive, costly and provide limited information, rapid and cost-effective methods providing continuous information on the subsurface are highly desirable. Geoelectrical techniques are non-invasive imaging methods that can `look' below the surface, much like an MRI scan, to detect features of interest. These techniques, which include electrical resistivity tomography (ERT) and induced polarization (IP), are seeing increasing application in environmental investigations. Since they measure the spatial variation of electrical properties, and contaminants typically have distinct electrical properties relative to groundwater (i.e., resistive DNAPL, conductive AMD), geoelectrical techniques have outstanding potential as investigative tools at contaminated sites. However, their common application has not been realized, due in part to the lack of tools and experience in interpreting geoelectrical responses from heterogeneous contaminant distributions in the subsurface. The ultimate goal of this research program is to establish geoelectrical techniques as field-proven tools for contaminated site investigations, including characterization and remediation activities. ERT is the most mature technique but requires critical research to jump to pilot-scale field trials. IP is newer and exciting but needs fundamental work to prove its value for certain contaminants and scenarios. In the short-term, this research program will focus on: (i) building the foundation for IP as a technique for mapping contaminated sites, (ii) translating initial success of ERT to pilot test field implementation, and (iii) launching geoelectrical techniques for mapping key emerging contaminants. The program is timely and is supplemented by the recent, transformative improvements occurring in geoelectrical imaging. It is expected to be a game changer in the remediation industry, leading to significant benefits to the Canadian environment and economy. Furthermore, it will train 3 MESc students, 2 PhD students and 5 undergraduate students and prepare them for key positions in the fast-growing environmental sector.

土壤和地下水受到危险化学品的污染，包括氯化溶剂和煤焦油(称为稠密非水相液体(DNAPL))以及其他人为化学品，如全氟烷基物质和多氟烷基物质(PFAS)，仍然是世界范围内的一个严重问题。仅在加拿大就有大约24,000个联邦污染场地，包括前工业用地、退役的炼油厂和废弃的加油站。2019年，联邦污染场地行动计划续签了15年，联邦政府承诺在前五年(2020年至2024年)提供11.6亿美元。其中，10.5亿美元已分配用于修复受污染的场地。成功的补救需要准确地了解污染物在哪里，以及它们被清除的速度有多快。由于常规方法，包括钻孔和监测井，具有侵入性，成本高，提供的信息有限，因此非常需要快速和具有成本效益的方法来提供地下连续信息。地电技术是一种非侵入性的成像方法，它可以像核磁共振扫描一样，在表面下‘观察’，以检测感兴趣的特征。包括电阻率层析成像(ERT)和激发极化(IP)在内的这些技术在环境调查中的应用越来越多。由于地电技术测量的是电学性质的空间变化，而且污染物通常相对于地下水具有不同的电学性质(即阻性DNAPL、导电AMD)，因此地电技术作为污染场地的调查工具具有突出的潜力。然而，它们的普遍应用尚未实现，部分原因是缺乏解释地下非均匀污染物分布的地电响应的工具和经验。这项研究计划的最终目标是建立地电技术，作为现场验证的工具，用于污染现场调查，包括表征和补救活动。ERT是最成熟的技术，但需要关键研究才能跳到中试规模的现场试验。IP是较新的和令人兴奋的，但需要基础工作来证明其在某些污染物和情景中的价值。在短期内，这项研究计划将侧重于：(I)为IP作为一种绘制受污染地点地图的技术奠定基础；(Ii)将ERT的初步成功转化为试验田实施；以及(Iii)推出用于绘制主要新兴污染物地图的地电技术。该计划是及时的，并得到了最近在地电成像方面发生的变革性改进的补充。预计它将改变补救行业的游戏规则，为加拿大的环境和经济带来显著的好处。此外，它还将培训3名MESc学生、2名博士生和5名本科生，为他们在快速增长的环境部门担任关键职位做好准备。