CAREER: Quantifying evolution of accessible mineral surface areas and pore connectivity for improved simulation of mineral reaction rates

化学反应是自然地下环境的重要组成部分，包括天然岩石的风化、污染物的移动和分解，以及二氧化碳储存、水力压裂和放射性废物处理等工业过程。其中许多过程发生在含水层中，孔隙度、渗透率和岩石表面化学成分随时间变化的方式对于预测污染物如何移动或水质变化至关重要。计算机模拟经常被用来帮助理解土壤和含水层在几年和几个世纪里是如何变化的，但模拟是困难的，因为实验室中测量的反应速度与自然界中的测量结果非常不同，原因尚不清楚。拟议的项目将寻求通过使用先进的成像方法、实验室岩石风化实验和计算机模拟来协调这些差异。这将有助于我们模拟和更好地了解污染物的去向、二氧化碳的封存、矿物的溶解和沉淀以及水质的变化等过程。该项目支持不同的本科生和研究生群体，他们将通过参与外联活动和奥本大学OutCELL教育计划，帮助提高对K-12学生在STEM领域的兴趣。长期的研究目标是加强对地下系统中矿物溶解和沉淀反应的速度、程度和影响的了解和模拟，以更好地预测这些系统中的流动和运输，从而改进风险和影响评估。作为迈向这一目标的一步，这项职业计划的研究目标是检验矿物反应速率和渗透率演变是矿物可获得表面积、孔隙率和孔隙连通性的函数的假设。该方法将进行岩心规模的实验室溶解实验，使用成像方法测量可访问矿物表面积、孔隙率和孔隙连通性的反应演化，并将成像观察整合到溶解实验的反应传输模拟中。我的长期教育目标是让学生掌握知识和技能，以评估环境系统中的命运和运输，并制定和实施环境问题的解决方案。为了实现这一目标，这项建议的教育目标是提高K-12、本科生和研究生对环境系统中水-岩石相互作用的理解和认识。教育方法是通过在奥本学生主导的OutCELL设施进行演示来扩大对K-12的认识，开发新的本科生/研究生课程材料，并建立一个永久性的跨学科学生研讨会系列。这项提议的外展目标是通过OutCELL和夏令营来扩大对STEM领域的兴趣和参与，并通过参与外展、指导和研究活动来支持本科生和研究生层面的持续兴趣。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Chemical reactions are an important part of natural subsurface environments, and this includes natural rock weathering, contaminant movement and breakdown, and industrial processes such as carbon dioxide storage, hydraulic fracturing, and radioactive waste disposal. Many of these processes occur in aquifers and the way that porosity, permeability, and rock surface chemistry change over time is crucial to predicting how contaminants move or the quality of water changes. Computer simulations are often used to help understand how soils and aquifers change over years and centuries but simulation is difficult because measurements of reaction rate in the laboratory are so different from measurements in nature and the reason is not clear. The proposed project will seek to reconcile these differences by using advanced imaging methods, laboratory rock weathering experiments, and computer simulations. This will help us simulate and better understand such processes as contaminant fate, carbon dioxide sequestration, the dissolution and precipitation of minerals, and changes in water quality. The project supports a diverse group of undergraduate and graduate students who will be engaged to help increase interest in STEM fields in K- 12 students through involvement in outreach activities and the Auburn University OutCELL educational programs. The long-term research goal is to enhance understanding and simulation of the rate, extent, and impact of mineral dissolution and precipitation reactions in subsurface systems to better predict flow and transport in these systems, enabling improved risk and impact assessment. As a step towards this goal, the research objective of this CAREER proposal is to test the hypothesis that mineral reaction rates and permeability evolution are a function of mineral accessible surface areas, porosity and pore connectivity. The approach will be to carry out core scale laboratory dissolution experiments, use imaging methods to measure the reactive evolution of accessible mineral surface area, porosity, and pore connectivity, and integrate imaging observations into reactive transport simulations of dissolution experiments. My long-term educational goal is to equip students with the knowledge and skills to assess fate and transport in environmental systems and develop and implement solutions to environmental problems. In pursuit of this goal, the educational objective of this proposal is to increase understanding and awareness of K-12, undergraduate and graduate students of water-rock interactions in environmental systems. The educational approach is to expand K-12 awareness through demonstrations at the Auburn student-led OutCELL facility, develop new undergraduate/graduate course materials, and establish a permanent interdisciplinary student seminar series. The outreach objective of this proposal is to broaden interest and participation in STEM fields by initiating interest at the K-12 level through OutCELL and summer camps and support continued interest at the undergraduate and graduate levels through participation in outreach, mentoring, and research activities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.