PFAS fate and transport in groundwater

Per- and poly-fluorylalkyl substances (PFAS) are a broad class of chemicals receiving increasing attention due to their widespread presence in the environment and potential to cause negative health consequences. We are studying the fate and transport of PFAS in efforts to quantify historical concentrations in the Santa Ana River and the Orange County groundwater basin.

Reactive flow and permeability alteration

Fluids that react with minerals in the earth can alter the hydrologic, geomechanical and geochemical properties of subsurface formations. Interactions and feedbacks between these processes challenge existing models. We use experimental and computational techniques to develop new insights to these coupled processes.

Non-Newtonian suspension flows

When fluids are laden with fine particles, the resulting suspension behaves quite differently from the fluid in the absence of the particle. We study the behavior of such non-Newtonian suspensions in fractures. These fundamental studies inform problems ranging from mud volcanoes to hydraulic fracturing.

Solute transport and interphase mass transfer

The spread of groundwater contamination is controlled by mass transfer between fluid phases and the transport of the dissolved contaminants in groundwater. We study these processes in the lab at the scale of single fractures or small sand chambers. We develop computational models of these processes that help us predict and understand migration of contaminants at the field scale.

Unsaturated flow and transport

Understanding flow and transport processes in unsaturated porous and fractured media is complicated by the interaction of the two fluid phases filling the pore space. We study two-phase flow in the lab using visualization techniques and develop scalable models to predict these processes. These studies support applied problems such as infiltration to the subsurface and geologic carbon sequestration.

Imaging techniques in porous and fractured media

Imaging flow and transport processes in porous and fractured media can lead to important insights into fundamental processes, especially when potentially competing mechanisms occur simultaneously (e.g. fluid flow / geochemical reactions / mechanical deformation). We develop and use novel imaging techniques for directly quantifying these processes during laboratory experiments.