Collaborative Research: Understanding the Effect of Transient Interfacial Dynamic in the Transport and Deposition of Particles in the Vadose Zone

合作研究：了解瞬态界面动力学对渗流区颗粒传输和沉积的影响

• 批准号: 1436482
• 负责人: Joelle Frechette
• 金额: $ 16.5万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1436482&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; Effect; Transient

1436482Frechette1437478DrazerCollaborative Research: Understanding the effect of transient interfacial dynamics in the transport and deposition of particles in the vadose zoneThe transport of small suspended particles, referred to as colloidal particles, in geological media has been the subject of numerous studies, due in part to its importance in contaminant spreading and water purification. The vadose zone, the upper levels of the soil column, is the entry point for the replenishment of groundwater reservoirs and, therefore, the transport and fate of particulates is key to the sustainability of water resources. Particulates containing contaminants, ranging from pathogenic microbes to the increasing number of nanoparticles used in industrial applications, can pollute groundwater reservoirs. In addition, it has been shown that colloidal particles can facilitate the transport of molecular contaminants. Unfortunately, the development of predictive models for the transport and fate of colloidal particles in the vadose zone has proven especially elusive. A better understanding of the mechanisms driving the transport of particulates in unsaturated porous media could lead to new paradigms in the design of water purification processes, the management of contamination risk, the development of remediation strategies, and would facilitate the recovery and recycling of technological nanomaterials. The impact of this work lies in both education and outreach, public health, as well as on its technologically enabling capabilities. Training will be provided to graduate students, undergraduates, and high school students in an interdisciplinary environment that includes a strong exposure to the fields of materials and interfacial science as well as transport and modeling. The investigators educational philosophy is designed to foster a true passion for science in students by giving them opportunities to actively produce scientific material, rather than acting as passive consumers. Outreach and educational efforts by the investigators will include course development, and the ongoing participation of undergraduates and high school students to the research activities. The investigators groups will also adopt an after-school classroom for a year (visiting the classroom weekly) in which students, under the guidance of a trained facilitator, will engage in hands-on STEM activities in the area of sustainability of water resources. In the lab, undergraduates and high school students are encouraged to present their findings within the group and externally, including authorship in peer-reviewed scientific publications.The technical portion of the proposed work lies in the broad scientific, technological, and economical importance of remediation of contaminants from groundwater, especially as the resources for potable water are becoming scarcer, the use of synthetic particulate and nanomaterials increases, and the cost of energy is skyrocketing. The transformative nature of the proposed work lies in providing a particle-level understanding of the role of non-equilibrium hydrodynamic and chemical transients on the attachment/detachment of particles from air-water (-solid) interfaces by the integration of state-of-the-art experimental and simulation tools. The results from the proposed work will also be important in other scientific areas such as water filtration, oil recovery, fouling in microfluidic devices, and clogging. Therefore, there is an important scientific and engineering rationale in understanding the mechanisms for particles adsorption and desorption from an air-water (-solid) interface during transient conditions. The design of simple and versatile experiments to address these issues will lead to an ideal platform to study particle deposition in unsaturated porous media. In addition, tools that will be developed for this work will allow, in the future, to study the deposition of more complex colloids such as bacteria, viruses, or minerals of various shapes and propensity to adsorb at fluid interfaces.

1436482 Frechette 1437478 Drazer合作研究：了解瞬态界面动力学在包气带中颗粒传输和沉积的影响地质介质中小悬浮颗粒（称为胶体颗粒）的传输一直是许多研究的主题，部分原因是其在污染物扩散和水净化中的重要性。包气带，即土柱的上层，是地下水库补给的入口点，因此，颗粒物的迁移和归宿是水资源可持续性的关键。含有污染物的颗粒，从致病微生物到工业应用中使用的越来越多的纳米颗粒，都可能污染地下水库。此外，已经表明胶体颗粒可以促进分子污染物的运输。不幸的是，发展预测模型的运输和命运的胶体颗粒在包气带已被证明是特别难以捉摸的。更好地了解推动颗粒在不饱和多孔介质中迁移的机制，可以为水净化工艺的设计、污染风险的管理、补救战略的制定提供新的范例，并将促进技术纳米材料的回收和再循环。这项工作的影响在于教育和外联、公共卫生以及技术能力。培训将提供给研究生，本科生和高中生在一个跨学科的环境，其中包括一个强大的接触材料和界面科学以及运输和建模领域。研究人员的教育理念旨在培养学生对科学的真正热情，让他们有机会积极制作科学材料，而不是充当被动的消费者。研究人员的外联和教育工作将包括课程开发，以及本科生和高中生对研究活动的持续参与。调查小组还将采用为期一年的课后课堂（每周参观教室），学生在训练有素的主持人的指导下，将在水资源可持续性领域参与实践STEM活动。在实验室里，鼓励本科生和高中生在小组内外展示他们的发现，包括在同行评议的科学出版物上发表论文。拟议工作的技术部分在于地下水污染物修复的广泛科学、技术和经济重要性，特别是在饮用水资源越来越稀缺的情况下，合成颗粒和纳米材料的使用增加，能源成本飞涨。所提出的工作的变革性在于提供一个粒子级的理解的作用，非平衡流体动力学和化学瞬变的附着/脱离的颗粒从空气-水（固体）界面的集成状态的最先进的实验和模拟工具。拟议工作的结果在其他科学领域也很重要，如水过滤，石油回收，微流体设备中的污垢和堵塞。因此，理解瞬态条件下颗粒从空气-水（-固体）界面吸附和解吸的机制具有重要的科学和工程原理。设计简单和通用的实验来解决这些问题，将导致一个理想的平台来研究颗粒在非饱和多孔介质中的沉积。此外，为这项工作开发的工具将允许在未来研究更复杂的胶体的沉积，如细菌，病毒或各种形状和倾向于在流体界面吸附的矿物质。