Collaborative Research: In Situ Laboratory Imaging and Modeling of PFAS Transport and Fate in Variably Saturated Heterogeneous Porous Media

全氟烷基和多氟烷基物质（PFAS）目前保留在地下水位以上的浅层地下水的浸出是地下水污染的一个持久来源。这个保留过程非常复杂，因为PFAS在浅层地下的流动性的时间和程度受土壤性质、气候和天气事件以及特定场地的水文地质条件的控制。尽管在理解PFAS的迁移和保留行为方面取得了重大进展，但关于地质特性的空间变化如何影响PFAS污染在地下水中迁移的方式、时间和地点，仍然存在重要的知识空白。这项研究进步的能力，测量和模拟PFAS迁移和保留在更现实的地质条件下。为不同背景的学生研究人员提供培训，并与处理PFAS污染问题的水专业人员进行外联。PFAS在地下迁移的更好的理解将使未来的进展PFAS修复strategy development.This项目使用医学成像技术和数值模型的最新进展，量化动态，空间可变PFAS吸附在非均质非饱和地质多孔介质。具体的目的是测量在饱和和部分饱和的非均相柱中的两个代表性的PFAS的原位吸附。这些延时成像测量，反过来，提供直接验证先进的空间分辨数值模型，并使开发的放大模型的PFAS运输下异质地下条件。这项工作提供了前所未有的原位传输和吸附测量，升级方法，用于描述和预测PFAS通过土壤到地下水含水层的淋溶的数值模型和参数化。该项目由GEO/CENTRAL水文科学（1579）计划和ENG/CBET环境工程（1440）联合资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Leaching of per- and polyfluoroalkyl substances (PFAS) currently retained in the shallow subsurface above the water table is a persistent source of groundwater contamination. This retention process is very complex because the timing and extent of PFAS mobility in the shallow subsurface are controlled by soil properties, climate, and weather events, and site-specific hydrogeologic conditions. Despite significant advances in understanding the migration and retention behavior of PFAS, there remains a critical knowledge gap on how spatial variation in geologic properties—which have a strong impact on groundwater flow processes—impact how, when, and where PFAS contamination migrates in the subsurface. This research advances the ability to measure and model PFAS migration and retention under more realistic geologic conditions. Training is provided to student researchers of diverse backgrounds, and outreach is conducted to engage with water professionals dealing with PFAS pollution problems. Improved understanding of PFAS migration in the subsurface will enable future progress in PFAS remediation strategy development.This project uses medical imaging technology and recent advances in numerical models to quantify dynamic, spatially variable PFAS adsorption in heterogeneous unsaturated geologic porous media. The specific aims are to measure in situ adsorption of two representative PFAS in saturated and partially saturated heterogeneous columns. These time-lapse imaging measurements are used, in turn, to provide direct validation to advanced spatially-resolved numerical models and enable the development of upscaled models of PFAS transport under heterogeneous subsurface conditions. This work offers unprecedented in situ transport and adsorption measurements, upscaling approaches, and parameterization of a numerical model used to describe and predict PFAS leaching through soils to groundwater aquifers.This project is jointly funded by the GEO/EAR Hydrologic Sciences (1579) Program and the ENG/CBET Environmental Engineering (1440) program.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.