Multiphysics of bubbles and nanoparticles in porous media: Novel approaches to the remediation of subsurface environments contaminated by chlorinated organic substances

多孔介质中气泡和纳米颗粒的多物理场：修复受氯化有机物质污染的地下环境的新方法

• 批准号: 194309-2013
• 负责人: Ioannidis, Marios
• 金额: $ 1.89万
• 依托单位: University of Waterloo
• 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=636558
• 关键词: Multiphysics; bubbles; nanoparticles; porous; media

Soil and groundwater at abandoned industrial facilities (brown-field sites) in Canada remain contaminated by chlorinated volatile organic compounds (VOCs), long after the use of these chemicals has ceased. Chlorinated organics are denser than water, causing subsurface contamination deep below the water table. Their intermediate by-products are believed to be potent carcinogens and are thus a major threat to groundwater resources. The success of many remediation strategies is limited by the difficulty of introducing a gas phase uniformly within VOC source zones below the water table, as would be necessary for transferring a VOC into the flowing gas phase or for supplying reactive gases (e.g., oxygen, hydrogen, methane) for use by contaminant-degrading bacteria. The overall aim of the proposed research is to develop radically new alternatives to present-day strategies for the remediation of a wide spectrum of subsurface environments (e.g., contamination deep below the water table and in fractured rock) compromised by VOCs. The proposed research program derives its novelty from the use of gas-supersaturated water injection (SWI) as the means for introducing a mobile gas-phase in situ. In this process, gas is not injected but exsolved in situ from injected water that contains an excess of dissolved gas (analogous to opening a can of soda pop). Using a synergy of experimentation and modeling at both the microscopic (pore-level) and macroscopic (continuum) scales, we address the following questions. Firstly, what mechanisms govern the interaction of flowing gas bubbles with VOC blobs trapped within soil and rock and how do we predict the extent of VOC removal by volatilization and/or mobilization at practically relevant scales? Secondly, how do we harness the interactions between flowing bubbles and hydrophobic nanoparticles to generate foam in situ and how can such a foam be used to remediate contaminated subsurface environments? In summary, this research program will develop innovative technologies that could increase the competitive advantage of Canadian companies active in the area of site redevelopment.displace a residual oil phase, (ii) improve sweep efficiency during SWI and (iii) control the emplacement of nano-scale zero-valent iron nanoparticles. We will complement these studies by experiments in 1D and 2D sand packs and rock cores with an aim to validate a continuum-scale model ofthree-phase flow with non-equilibrium inter-phase mass transfer that could serve as a tool for the design offield-scale tests.The proposed research program will integrate experiments and modeling at scales ranging from the scale of asingle gas-liquid interface (dynamic surface tension during irreversible adsorption of nanoparticles) to the porenetwork scale (oil gangion-gas bubble dynamics) to macroscopic 1D and 2D domains. It will provide HQPtraining for 2 PhD, 2MASc and 2 undergraduate co-op students, offering unique opportunities for discoveriesin technological fields not limited to soil remediation, but including enhanced oil recovery and geologicalsequestration of carbon dioxide.

加拿大废弃工业设施（棕地）的土壤和地下水在停止使用氯化挥发性有机化合物 (VOC) 很久之后仍然受到这些化学品的污染。氯化有机物的密度比水大，导致地下水位以下深处的地下污染。它们的中间副产品被认为是强效致癌物，因此对地下水资源构成重大威胁。许多修复策略的成功受到在地下水位以下 VOC 源区域内均匀引入气相的困难的限制，而这对于将 VOC 转移到流动气相或供应活性气体（例如氧气、氢气）是必要的。 、甲烷）供污染物降解细菌使用。拟议研究的总体目标是开发全新的替代方案来替代目前的策略，以修复受挥发性有机化合物影响的各种地下环境（例如，地下水位深处和裂隙岩石中的污染）。拟议的研究计划的新颖之处在于使用气体过饱和水注入（SWI）作为原位引入流动气相的手段。在此过程中，气体不是注入，而是从含有过量溶解气体的注入水中原位溶解（类似于打开一罐汽水）。利用微观（孔隙水平）和宏观（连续体）尺度上的实验和建模的协同作用，我们解决了以下问题。首先，什么机制控制着流动的气泡与土壤和岩石中捕获的 VOC 斑点的相互作用，以及我们如何预测实际相关规模下通过挥发和/或动员去除 VOC 的程度？其次，我们如何利用流动气泡和疏水纳米颗粒之间的相互作用来原位产生泡沫，以及如何使用这种泡沫来修复受污染的地下环境？总之，该研究计划将开发创新技术，提高活跃在场地再开发领域的加拿大公司的竞争优势。置换残余油相，(ii) 提高 SWI 期间的波及效率，(iii) 控制纳米粒子的安置-规模零价铁纳米颗粒。我们将通过一维和二维砂包和岩心实验来补充这些研究，目的是验证具有非平衡相间传质的三相流的连续尺度模型，该模型可以作为现场设计的工具。所提出的研究计划将在从单一气液界面尺度（纳米颗粒不可逆吸附过程中的动态表面张力）到孔隙网络尺度（石油神经节-气泡动力学）到宏观一维和二维域。它将为 2 名博士生、2 名硕士生和 2 名本科生提供 HQP 培训，为技术领域的发现提供独特的机会，不仅限于土壤修复，还包括提高石油采收率和二氧化碳地质封存。