Associate 2010-11

Craig M Bethke


Bioreactive Transport of Contaminant Chemicals in Flowing Groundwater

Once contaminant chemicals leech into groundwater and begin flowing through the subsurface, their pattern of migration is subject to an array of physical, chemical, and biologic phenomena. Each of these areas is studied by practitioners of a distinct specialty of geoscience. Researchers weave these threads of expertise into a fate and transport model to describe what is happening and then devise remediation measures to safeguard human and environmental health.

Given the high cost of remediation, as well as the acute human health issues at stake, there is substantial interest in improving quantitative models of this class. Researchers would especially like to account for the role of subsurface microorganisms. Microbes residing underground in pores and fractures of the crust comprise more than half of Earth’s biomass. The microbes can oxidize and reduce contaminants, transform them chemically, and drive reactions that immobilize them.

During his Center appointment Professor Bethke will pose and compute bioreactive transport models that describe the actions and evolution of the microbial community in aquifers. The goal of the project is to describe contaminant fate and transport in ways that are thermodynamically consistent and mechanistically based and that honor the principles of population ecology.

He will carry out this work at Stanford University, which has a unique set of resources and expertise for pursuing research of this type. The models he computes will form the basis of a book, Fate and Transport of Contaminants in Groundwater, to be published by Cambridge University Press. The book will explore in detail the construction, application, and interpretation of bioreactive transport models.