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

临界区从土壤表面延伸至 区域地下水位以下的地下水支持着几乎所有的陆地生物 并含有大部分陆地生物量。我们有能力做得更好 定量预测水流、化学运动和气体交换 地下对于准确评估许多 环境问题以及相关的管理和/或补救计划。一个 对控制机制和过程有更好的基本了解 水的运动以及土壤中化学污染物的归宿和迁移 鉴于我们对即将发生的气候的最佳估计，地下水变得更加紧迫 变化对气温和降水的影响。我们目前的知识和 定量预测水流、污染物迁移的能力仍然至关重要 当空气（气相）和水共存（多相流体）时受到限制 地下。 这是在非饱和土壤和滞留空气中的情况 关键区域的浅层地下水，特别是当 土壤和岩石的润湿性/排斥性是动态的（取决于时间）。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）特性。 特殊土壤的例子 敏感的是具有高有机质含量的防水干燥土壤，后 野火土壤以及被石油产品和工业污染的土壤 溶剂。 润湿性和毛细管现象的问题 随着时间的推移，许多环境污染物的变化变得更加复杂 天然存在的化合物充当表面活性化合物（表面活性剂） 显着改变空气-水界面处的表面张力， 固体表面的润湿性和接触角。我有广泛的研究 我的创新研究和研究经验以及长期的国际声誉 关于溶质浓度依赖性毛细管现象、接触角的出版物 动力学和分数润湿性对土壤水行为的影响。那些 贡献、知识和专长是拟议的基础 研究。 科学方法将很好地结合起来 基于实验室的仪器化流动池实验、数学模型 开发和实地研究。未来 5 年的主要目标成果 几年将开发概念数据集、概念模型的证明， 一阶动态水力函数和定量一阶 土壤水分渗透和滞留的数学模型 动态润湿性和毛细管作用。 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 修复专家、林务员、生态水文学家）能够计算 更准确、更可靠的水渗透、污染物传输行为 以及由此产生的土壤