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

化学反应是天然地下环境的重要组成部分，包括天然岩石风化，污染物移动和分解，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。 许多这些过程发生在含水层和孔隙度，渗透率和岩石表面化学随时间变化的方式是至关重要的预测污染物如何移动或水质的变化。 计算机模拟通常用于帮助了解土壤和含水层如何多年和几个世纪的变化，但模拟是困难的，因为在实验室中测量的反应速率与自然界中的测量是如此不同，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调和这些差异。这将有助于我们模拟和更好地了解污染物命运，二氧化碳封存，矿物质的溶解和沉淀以及水质变化等过程。该项目支持本科生和研究生的多元化群体，他们将通过参与外展活动和奥本大学OutCELL教育计划，帮助提高K- 12学生对STEM领域的兴趣。长期研究目标是加强对地下系统中矿物溶解和沉淀反应的速率、程度和影响的理解和模拟，以更好地预测这些系统中的流动和运输，从而改善风险和影响评估。作为实现这一目标的一步，本CAREER提案的研究目标是检验矿物反应速率和渗透率演变是矿物可及表面积、孔隙度和孔隙连通性的函数这一假设。该方法将是进行核心规模的实验室溶解实验，使用成像方法来测量可访问的矿物表面积，孔隙度和孔隙连通性的反应演化，并将成像观测纳入溶解实验的反应运输模拟。我的长期教育目标是使学生掌握评估环境系统中的命运和运输的知识和技能，并制定和实施环境问题的解决方案。为了实现这一目标，本提案的教育目标是提高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设施的演示来扩大K-12的认识，开发新的本科/研究生课程材料，并建立一个永久的跨学科学生研讨会系列。该提案的外联目标是通过OutCELL和夏令营在K-12级别引发兴趣，扩大对STEM领域的兴趣和参与，并通过参与外联，辅导，该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，更广泛的影响审查标准。

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.