SMALL GRANTS FOR EXPLORATORY RESEARCH (SGER): DEVELOPMENT AND USE OF A VISUALIZATION TECHNIQUE TO BETTER DEFINE MECHANISMS FOR PARTICLE TRANSPORT IN POROUS MEDIA

探索性研究小额资助 (SGER)：开发和使用可视化技术以更好地定义多孔介质中的颗粒传输机制

• 批准号: 0551834
• 负责人: John Germaine
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-10-15 至 2006-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0551834&HistoricalAwards=false
• 关键词: SMALL; GRANTS; EXPLORATORY; RESEARCH; SGER

0551834 GermaineUnderstanding particle transport in porous media is important to a number ofproblems involving subsurface flow and transport, water and waste-water treatment, andsoil pedology. The migration behavior of particles in porous media is complex. Factorsinfluencing this behavior include the particle density, size and surface chemistry, thewater chemistry, the interstitial velocity, and the characteristics of the porous medium. Inthe case of biological particles, motility, chemotaxis, growth and decay are alsoinfluential.Considerable insight into particle transport in porous media has been gained fromexperimental programs based on batch and column testing. Nonetheless, work of thisnature cannot resolve, in real-time, the processes governing particle transport in theinterior of a porous medium. This limits the scale of understanding that can be gainedfrom such experimental approaches. In order to further understanding of the fundamentalprocesses governing particle fate and transport in porous media, alternative methods thatinvolve visualization studies of particle behavior within a porous medium are needed.In prior work, the Investigators of this proposal developed a visualizationtechnique to study particle behavior in the interior of a porous medium. Use of thistechnique enabled the proposition of new hypotheses regarding particle transportbehavior. The goals of this exploratory research project are to further the newvisualization technique, and to provide further support for the emerging hypotheses onparticle transport behavior. Specifically, the project will:1. Extend the new visualization technique to enable better resolution of particlebehavior, including resolution of individual particle tracks at the micro-scale anddistinction between aqueous and solid phase particles at the macro-scale.2. Prove, irrefutably, that, during non-Brownian particle transport underunfavorable electrostatic conditions, observations of decreasing particle attachment ratewith transport distance are attributable to the early filtration of heavier particles as aresult of gravitational sedimentation, and3. Establish the impact of flow direction on particle transport for micron-sizedparticles whose behavior is, theoretically, dominated by Brownian motion.Broader Impacts The proposed research will provide a visualization tool that canspatially and temporally resolve microscopic and macroscopic particle concentrations inthe interior of a porous medium. The research will also improve understanding ofattachment and detachments mechanisms that impact particle interaction with a medium'ssolid phase. In particular, it will provide an explanation for why irreversible particleattachment rates decrease with transport distance under unfavorable electrostaticconditions. Research training will be provided for one graduate student. Undergraduatestudents will also be engaged in the research through MIT's Undergraduate ResearchOpportunities Program.

了解多孔介质中的颗粒输运对于解决地下水流和输运、水和废水处理以及土壤土壤学等问题非常重要。颗粒在多孔介质中的运移行为是复杂的。影响这种行为的因素包括颗粒密度、尺寸和表面化学、水化学、间隙速度和多孔介质的特性。在生物颗粒的情况下，运动性，趋化性，生长和衰变也是有影响的。相当深入的了解颗粒在多孔介质中的传输已经获得了从实验程序的基础上批和柱测试。尽管如此，这种性质的工作不能解决，在实时，在多孔介质的内部的颗粒运输的过程。这限制了从这些实验方法中获得的理解的范围。为了进一步了解多孔介质中颗粒的命运和输运的基本过程，需要对多孔介质中颗粒行为进行可视化研究的替代方法。在先前的工作中，本研究计划的研究人员开发了一种可视化技术来研究多孔介质内部的颗粒行为。使用这种技术使新的假设的命题有关粒子的运输行为。这项探索性研究项目的目标是进一步发展新的可视化技术，并为粒子输运行为的新兴假设提供进一步的支持。具体而言，该项目将：1。扩展新的可视化技术，使粒子行为的分辨率更高，包括在微观尺度上单个粒子轨迹的分辨率和在宏观尺度上区分水相和固相粒子。无可辩驳地证明，在不利的静电条件下的非布朗粒子输运过程中，粒子附着率随输运距离而降低的观测结果可归因于重力沉降导致的较重粒子的早期过滤，以及3.建立流动方向对微粒传输的影响，其行为在理论上是由Brownian motion.Broader Impacts主导的。该研究将提供一种可视化工具，可以在空间和时间上分辨多孔介质内部的微观和宏观颗粒浓度。这项研究还将提高对影响颗粒与介质固相相互作用的附着和分离机制的理解。特别是，它将提供一个解释，为什么不可逆的particleattachment率下降，在不利的electrostatic条件下的运输距离。将为一名研究生提供研究培训。本科生也将通过麻省理工学院的本科生研究机会计划参与研究。