Redefining Surface Area: Understanding Reactive Interfaces in Heterogeneous Porous Media

重新定义表面积：了解异质多孔介质中的反应界面

• 批准号: 1452007
• 负责人: Li Li
• 金额: $ 19.31万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1452007&HistoricalAwards=false
• 关键词: Redefining; Surface; Area; Understanding; Reactive

Redefining Surface Area: Understanding Reactive Interfaces in Heterogeneous Porous MediaBiogeochemical reaction rates in the natural subsurface are typically controlled by those at the "hot" reactive interfaces where fluids and solids of different properties and conditions meet. These interfaces are often restricted to relatively small, sharp zones with rates orders of magnitude higher than those at the rest of the domain. The research outcomes from this project will be important for a broad spectrum of applications at the nexus of energy, water, and environment. In particular, they will advance understanding and predicting of physical, chemical, and biological processes important for shale gas development, acid mine drainage, nuclear waste disposal, geological CO2 sequestration, geothermal energy, and contaminant transport. Fundamental understanding of the earth systems, including the Critical Zone where humans live, is also essential for soil fertility and productivity, water sustainability, and energy security, all of which are subject to climate change and intense human activities in the Anthropocene.In this study the investigator hypothesizes that the emergence and nature of reactive interfaces are dictated by spatial heterogeneities, the spatial variations in porous medium properties and conditions. These reactive interfaces ultimately govern large scale processes and system functioning. Whereas hydrologists have documented significant impacts of physical heterogeneities on fluid flow and solute transport in the past decades, present understanding on the role of physical and geochemical heterogeneities in determining (bio)geochemical processes has not kept pace. The investigator proposes to understand fundamental principles that govern the occurrence and functioning of reactive interfaces. The ultimate goal is to develop conceptual and predictive framework for geochemical processes in natural, heterogeneous subsurface. The proposed work will integrate two-dimensional flow-through experiments and multi-scale reactive transport modeling. The 2D flow cells will be packed using calcite, chlorite, and quartz-minerals that differ drastically in reactivity and are ubiquitous in natural systems. Understanding reactive interfaces will enable a significant step toward unifying observations across scales. The goal of the education and outreach plan is to empower the science community and general public with tools and education in ways that transcend limits of time, space, and individual disciplines. The investigator proposes to (1) develop an online module with a "heterogeneity" focus as part of a much-needed online reactive transport modeling (RTM) course for delivery through Penn State's World Campus; (2) develop a repository website that organizes the online teaching materials for free access to the public; (3) promote diversity and environmental awareness by offering underrepresented high school students a summer research opportunity on "Water flow through rocks". The plan will equip the community with knowledge and predictive tools for environmental stewardship, water management, as well as protection and sustainable use of natural resources.

重新定义表面积：了解多相多孔介质中的反应界面天然地下的生物化学反应速率通常由不同性质和条件的流体和固体相遇的“热”反应界面上的反应速率控制。这些界面通常被限制在相对较小、尖锐的区域，其速率比域中其他区域的速率高几个数量级。该项目的研究成果将对能源、水和环境的广泛应用具有重要意义。特别是，它们将促进对页岩气开发、酸性矿山排水、核废物处理、地质二氧化碳封存、地热能和污染物运输等重要物理、化学和生物过程的理解和预测。对地球系统的基本了解，包括人类生活的临界区，对于土壤肥力和生产力、水的可持续性和能源安全也是至关重要的，所有这些都受到气候变化和人类强烈活动的影响。在这项研究中，研究者假设反应界面的出现和性质是由空间异质性、多孔介质性质和条件的空间差异决定的。这些反应性接口最终控制着大规模的流程和系统功能。在过去的几十年里，水文学家已经证明了物理非均质性对流体流动和溶质运移的重大影响，但目前对物理和地球化学非均质性在确定(生物)地球化学过程中的作用的理解并没有跟上步伐。研究人员建议理解支配反应性界面的发生和功能的基本原理。最终目标是为自然、非均质地下的地球化学过程开发概念性和预测性框架。拟议的工作将结合二维流动实验和多尺度反应输运模型。2D流动池将使用方解石、绿泥石和石英填充，这些矿物的反应性差异很大，在自然系统中随处可见。了解反应性界面将使我们朝着统一不同尺度的观测迈出重要的一步。教育和推广计划的目标是以超越时间、空间和个别学科限制的方式，为科学界和普通公众提供工具和教育。研究人员建议(1)开发一个以“异质性”为重点的在线模块，作为宾夕法尼亚州立大学世界校园亟需的在线反应运输建模(RTM)课程的一部分；(2)开发一个知识库网站，组织在线教材，供公众免费使用；(3)通过向未被充分代表的高中生提供夏季研究“岩石中的水”的机会，促进多样性和环境意识。该计划将使社区具备环境管理、水管理以及保护和可持续利用自然资源的知识和预测工具。