Mixed contaminants in soil and groundwater - some fundamental problems and their relevance to remediation and treatment

土壤和地下水中的混合污染物 - 一些基本问题及其与修复和处理的相关性

• 批准号: RGPIN-2018-03832
• 负责人: Li, Loretta
• 金额: $ 3.13万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=688665
• 关键词: Mixed; contaminants; soil; groundwater; some

Mixed contaminants pose major challenges in soil remediation and groundwater treatment. This proposal addresses the urgent need to study the effects of mixed contaminants in soil and groundwater. The proposed work will go beyond single classes of contaminants (e.g. lead, copper, zinc; petroleum hydrocarbon, brominated or fluorinated compounds). Significant gaps in current understanding of these contaminants include contaminant fate and transport in soil when present in mixtures, and transformation mechanisms, particularly in low-mobility zones, potential synergies among treatment technologies, and transport of mixed contaminants in plumes.******My research is primarily focused on understanding fate and transport processes of contaminants, to help improve environmental protection and management practice, with the goals of preventing the spread of contaminants, and reducing adverse health and ecological risks. Many of the perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water are linked to specific sources, such as industrial sites, military fire-training areas and wastewater treatment plants. It is important to recognize that almost all PFAS-contaminated sites contain more than one contaminant in groundwater, often in commingled plumes, including fuel components such as petroleum products, chlorinated solvents and non-chlorinated compounds, e.g. simultaneously released to the sub-surface during fire-fighting training exercises. Despite this common co-existence of two or more contaminants, detailed study of the fate and transport of PFASs in relation to co-contaminants and co-contaminant remediation is largely missing to date. ******The proposed work will seek to provide insight into the fundamental fate and transport processes that control the impact of PFAS, as well as comingled polycyclic aromatic hydrocarbons (PAHs) and 1,4-dioxane, in groundwater. We will particularly focus on the release and transformation of polyfluoroalkyl to the more problematic perfluoroalkyl substances in source zones, as well as the degree of success of commonly employed remediation technologies, which tend to be based on single contaminants. The specific short-term objectives are to: (1) investigate the fundamental mechanisms controlling sorption and release of PFASs from complex soil media; (2) examine the diffusion and potential abiotic reactions of PFASs and comingled contaminants in low-permeability soils; and determine the effects of PAHs, 1,4-dioxane and degradation byproducts on breakthrough of PFASs and their degradation products in one-dimensional flow-through soil columns. The ultimate goal of improved insight into the fundamental fate and transport processes in these mixed contaminant systems is to facilitate the development and optimization of treatment strategies for management of PFAS-sites in which there are comingled co-contaminants.

混合污染物给土壤修复和地下水处理带来了重大挑战。该提案解决了研究土壤和地下水中混合污染物影响的迫切需要。拟议的工作将超越单一类别的污染物（例如铅、铜、锌、石油烃、溴化或氟化化合物）。目前对这些污染物的认识存在重大差距，包括混合物中污染物的归宿和在土壤中的迁移，以及转化机制（特别是在低迁移率区域）、处理技术之间的潜在协同作用以及羽流中混合污染物的迁移。***** *我的研究主要集中在了解污染物的归宿和传输过程，以帮助改善环境保护和管理实践，目标是防止污染物扩散，减少不利的健康和生态风险。 饮用水中的许多全氟烷基和多氟烷基物质 (PFAS) 都与特定来源有关，例如工业场所、军事消防训练区和废水处理厂。 重要的是要认识到，几乎所有 PFAS 污染场地的地下水中都含有不止一种污染物，通常以混合羽流的形式存在，包括石油产品、氯化溶剂和非氯化化合物等燃料成分。在消防训练演习期间同时释放到地下。 尽管两种或多种污染物普遍共存，但迄今为止，仍缺乏对 PFAS 与共污染物和共污染物修复相关的归宿和迁移的详细研究。 ******拟议的工作将寻求深入了解地下水中控制 PFAS 以及混合多环芳烃 (PAH) 和 1,4-二恶烷影响的基本归宿和迁移过程。我们将特别关注源区多氟烷基物质向问题较多的全氟烷基物质的释放和转化，以及常用修复技术的成功程度，这些技术往往基于单一污染物。具体的短期目标是：（1）研究复杂土壤介质中控制PFASs吸附和释放的基本机制； (2) 检查低渗透土壤中 PFAS 和混合污染物的扩散和潜在非生物反应；并确定多环芳烃、1,4-二恶烷和降解副产物对一维流过土壤柱中 PFAS 及其降解产物突破的影响。 深入了解这些混合污染物系统的基本归宿和传输过程的最终目标是促进开发和优化处理策略，以管理存在混合共污染物的 PFAS 场所。