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

加拿大废弃工业设施（棕地）的土壤和地下水仍然受到氯化挥发性有机化合物（VOCs）的污染，即使这些化学品已经停止使用很久。氯化有机物的密度比水大，导致地下水位以下的地下污染。 它们的中间副产品被认为是强致癌物，因此是对地下水资源的主要威胁。许多补救策略的成功受到将气相均匀引入地下水位以下的VOC源区域内的困难的限制，这对于将VOC转移到流动的气相中或对于供应反应性气体（例如，氧气、氢气、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，以取代目前用于修复各种地下环境的战略（例如，地下水位以下和断裂岩石中的污染）受到VOC的影响。拟议的研究计划源于其新奇，从使用气体过饱和水注入（SWI）的手段，用于引入一个移动的气相原位。在这个过程中，气体不是注入的，而是从含有过量溶解气体的注入水中原位析出（类似于打开一罐苏打汽水）。在微观（孔隙水平）和宏观（连续）尺度上使用实验和建模的协同作用，我们解决了以下问题。 首先，是什么机制控制着流动气泡与土壤和岩石中挥发性有机化合物的相互作用，以及我们如何预测挥发性有机化合物在实际相关尺度上的挥发和/或流动去除程度？ 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，以提高活跃在场地重建领域的加拿大公司的竞争优势。 驱替残余油相，（ii）提高SWI期间的波及效率和（iii）控制纳米级零价铁纳米颗粒的就位。我们将通过在一维和二维填砂和岩心中的实验来补充这些研究，目的是验证连续尺度模型， 具有非平衡相间传质的三相流，可以作为设计 现场规模的测试。 拟议的研究计划将整合实验和建模规模从一个 单个气液界面（纳米颗粒不可逆吸附期间的动态表面张力） 网络尺度（油神经节-气泡动力学）到宏观1D和2D域。它将提供HQP 为2名博士，2名硕士和2名本科合作学生提供培训，提供独特的发现机会 在技术领域不仅限于土壤修复，但包括提高石油采收率和地质 二氧化碳的封存。

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 of three-phase flow with non-equilibrium inter-phase mass transfer that could serve as a tool for the design of field-scale tests. The proposed research program will integrate experiments and modeling at scales ranging from the scale of a single gas-liquid interface (dynamic surface tension during irreversible adsorption of nanoparticles) to the pore network scale (oil gangion-gas bubble dynamics) to macroscopic 1D and 2D domains. It will provide HQP training for 2 PhD, 2MASc and 2 undergraduate co-op students, offering unique opportunities for discoveries in technological fields not limited to soil remediation, but including enhanced oil recovery and geological sequestration of carbon dioxide.