CAREER: Coupled Phenomena Resilience and Dynamics in Bentonite Barriers

这一学院早期职业发展(CALEAR)奖将解决国家和全球在水安全、环境保护和培养未来STEM专业人员方面的挑战。这项研究的重点是改变我们测量、预测和教育他人关于用于环境保护的粘土屏障的长期性能的方式。工程粘土屏障，特别是那些使用膨润土粘土的屏障，通常被用来保护社区及其水资源免受工业、城市和放射性废物的污染。随着时间的推移，在不断变化的地理环境中保持保护性屏障的性能，对于保护国家水质和公众健康至关重要。然而，现场膨润土中发生的各种化学、温度、水力和应力条件对污染物通过屏障的传输速度具有复杂的、耦合的影响。直到最近，对这些耦合现象的研究主要集中在过于简化的条件上，这些条件不能代表暴露在废物中的粘土屏障的真实动态。这项研究包括对膨润土屏障在更现实条件下的污染物耦合运移特性的综合实验和分析评估。这些结果将改进污染物如何随着时间的推移通过粘土屏障逃逸的预测和建模，支持弹性屏障系统的设计，并改善对公众健康和环境的保护。综合教育和研究目标包括为本科生提供研究经验，为妇女和代表性不足的群体提供初中和高中STEM外展，以及开发活动图书馆以促进地球环境工程教育。这项研究的目的是促进对环境动态和耦合现象如何影响膨润土基围堵屏障的长期弹性的科学理解。该项目包括对膨润土在化学、温度、水力和应力条件变化下的耦合传输特性进行高级实验测量，包括原始样品和现场挖掘样品。综合研究和教育计划的目标包括：(I)测量传统膨润土和聚合物增强膨润土的耦合现象和化学传输特性；(Ii)改进通过粘土的耦合质量通量的模拟；(Iii)通过指导研究经验让本科生参与；以及(Iv)开发一个数字活动图书馆，以加强地质环境工程教育。这些结果将回答有关不断变化的化学-水力-热应力条件、现场暴露和材料增强如何影响屏障性能的基本问题。该项目将允许PI推进岩土、环境和水资源工程以及粘土科学方面的知识基础，并支持她在创新的地球环境研究方面的长期职业生涯。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。

This Faculty Early Career Development (CAREER) award will address national and global challenges of water security, environmental protection, and preparation of future STEM professionals. The research focuses on transforming how we measure, predict, and educate others about the long-term performance of clay barriers used for environmental protection. Engineered clay barriers, particularly those utilizing bentonite clay, are commonly used to protect communities and their water resources from pollutants from industrial, municipal, and radioactive wastes. Sustaining performance of protective barriers over time within evolving geoenvironments is critical to preserving national water quality and public health. However, variable chemical, temperature, hydraulic, and stress conditions that occur in bentonite in the field have complex, coupled effects on the rate of contaminant transport through the barrier. Until recently, research on these coupled phenomena has primarily focused on overly-simplified conditions that do not represent the real-world dynamics of clay barriers exposed to wastes. This research includes comprehensive experimental and analytical evaluation of coupled contaminant transport properties of bentonite barriers under more realistic conditions. The results will improve prediction and modeling of how contaminants escape through clay barriers over time, supporting design of resilient barrier systems and improved protection of public health and the environment. The integrated education and research objectives include research experiences for undergraduate students, middle and high school STEM outreach for women and underrepresented groups, and development of an activity library to advance geoenvironmental engineering education. The goal of this research is to advance scientific understanding of how environmental dynamics and coupled phenomena impact long-term resiliency of bentonite-based containment barriers. The project includes advanced experimental measurements of coupled transport properties of bentonites under changing chemical, temperature, hydraulic, and stress conditions for both virgin and field-exhumed samples. The objectives of the integrated research and education plan include: (i) measurement of coupled phenomena and chemical transport properties of traditional and polymer-enhanced bentonites; (ii) improved modelling of coupled mass flux through clays; (iii) undergraduate involvement through mentored research experiences; and (iv) development of a digital activity library to enhance geoenvironmental engineering education. The results will answer fundamental questions about how barrier performance is impacted by evolving chemical-hydraulic-thermal-stress conditions, field exposure, and material enhancement. This project will allow the PI to advance the knowledge base in geotechnical, environmental and water resources engineering, as well as clay science, and support her long-term career in innovative geoenvironmental research.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.