Dynamic Repellency, Wettability and Capillarity as Primary Drivers for Water Flow and Chemical Transport in Soils and Groundwater in the Critical Zone

动态排斥性、润湿性和毛细管作用是关键区域土壤和地下水中水流和化学物质输送的主要驱动力

• 批准号: RGPIN-2020-06614
• 负责人: Smith, James
• 金额: $ 1.82万
• 依托单位: McMaster 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=718068
• 关键词: Dynamic; Repellency; Wettability; Capillarity; Primary

The critical zone which extends form the soil surface down to groundwater below the regional water table supports almost all terrestrial life and contains most of the terrestrial biomass. Our ability to better quantitatively predict water flow, chemical movement and gas exchange in the subsurface is essential and foundational to accurately assessing many environmental problems and associated management and/or remediation schemes. A better fundamental understanding of mechanisms and processes controlling the movement of water and the fate and transport of chemical contaminants in the soil and groundwater is ever more urgent given our best estimates of pending climate change impacts on temperatures and precipitation. Our current knowledge and ability to quantitatively predict water flow, contaminant transport remain critically limited when both air (gas-phase) and water coexist (multi-phase fluids) in the subsurface. This is the case in unsaturated soils and entrapped air in shallow groundwaters of the critical zone, and particularly limited when the wettability/repellency of the soils and rocks is dynamic (time-dependent). It is critically limited when spilled contaminants have surface active (surfactant) properties. Examples of soils which are exceptionally sensitive are water repellent dry soils with high organic matter contents, post wildfire soils, and soils contaminated by petroleum products and industrial solvents. The problem of wettability and capillarity changing over time are complicated by the fact that numerous environmental contaminants and naturally occurring compounds act as surface active compounds (surfactants) which substantially change the surface tension at the air water interface, the wettability and contact angle at solid surfaces. I have extensive research experience and a long international reputation for my innovative research and publications on solute concentration dependent capillarity, contact angle dynamics and fractional wettability effects on soil water behavior. Those contributions, knowledge and expertise are foundational to the proposed research. The scientific approach will combine well instrumented laboratory-based flow cell experiments, mathematical model development, and field studies. The primary targeted outcomes over the next 5 years will be to develop proof of concept data sets, conceptual models, first-order dynamic hydraulic functions and quantitative first-order mathematical models of water infiltration and retention in soils expressing dynamic wettability and capillarity. The research will generate simple first-order practical models for specialists and non-specialists (e.g. environmental remediation specialists, foresters, eco-hydrologists) to be able to calculate more accurate and reliable water infiltration, contaminant transport behaviours and resultant soil

延伸的临界区域形成土壤表面至 区域地下水位下方的地下水几乎支撑着所有陆地生命 并包含大多数陆生生物量。我们更好的能力 定量预测水流，化学运动和气体交换 地下是必不可少的，并且是准确评估许多 环境问题以及相关的管理和/或补救计划。一个 对控制机制和过程的基本理解 水以及化学污染物在土壤中的命运和运输 鉴于我们对待解决气候的最佳估计，地下水变得更加紧迫 改变对温度和降水的影响。我们当前的知识和 定量预测水流的能力，污染物的运输保持批判性 限制空气（气相）和水中的水（多相流体） 地面。 在不饱和土壤中就是这种情况 关键区域的浅地下水，尤其有限 土壤和岩石的润湿性/驱除性是动态的（依赖时间）。它 当溢出的污染物具有表面活性时，受到严重限制 （表面活性剂）性质。 土壤异常的示例 敏感的是驱蚊剂的干燥土壤，有机物含量高， 野火土壤和石油产品和工业污染的土壤 溶剂。 润湿性和毛细血管的问题 随着时间的流逝而改变，这一事实使许多环境污染物变得复杂 天然发生的化合物充当表面活性化合物（表面活性剂） 这大大改变了空气水接口处的表面张力， 固体表面的润湿性和接触角。我有广泛的研究 我的创新研究和 有关溶质浓度依赖毛细血管的出版物，接触角 动力学和分数润湿性对土壤水行为的影响。那些 贡献，知识和专业知识是拟议中的基础 研究。 科学方法将很好地结合 仪器基于实验室的流动池实验，数学模型 开发和现场研究。接下来的5个主要目标结果 多年是为了制定概念数据集的证明，概念模型， 一阶动力液压函数和定量的一阶 表达土壤中的水浸润和保留的数学模型 动态的润湿性和毛细血管。 该研究将产生简单的一阶 专家和非专家的实用模型（例如环境 补救专家，林业者，生态流行病学家）能够计算 更准确，可靠的水渗透，污染物的运输行为 和由此产生的土壤