Research Focus
We study the behavior of inorganic and organic contaminants in aqueous geochemical (soil, sediment) and engineered (waste and storm water) settings. The mechanisms and kinetics of contaminant interactions with mineral phases determine the mobility and bioaccessibility of these species in affected systems. Understanding these processes has important implications for predicting the fate of contaminant species in the environment.

We use laboratory-based model systems, field work, and advanced molecular-scale techniques; as applied to the areas of contaminant geochemistry, urban geochemistry and sustainable geochemistry. Current research topics include the assessment of heavy metal contamination of human-impacted soils, and the evaluation of alternative mineral fertilizers as related to the sustainable use of natural resources.

 Sustainable Geochemistry
Recovery of usable products from waste sources can ensure sustainable use of the Earth's resources. We are currently exploring wastes as a source of recyclable nutrients. The current focus is the geochemistry of phosphate minerals recovered from animal and plant wastes as compared to geogenic analogs.
Contaminant Geochemistry
The solid state speciation of contaminants such as arsenic, chromium and lead can dictate their mobility in the presence of mineral phases in geochemical systems. We use XAFS to determine the molecular-scale configuration of these and other contaminants associated with minerals to evaluate susceptibility to mobilization.

Urban Geochemistry
Metals accumulate in urban areas due to the convergence of several anthropogenic activities. These metals impact soils, water and vegetation in such highly populated areas. As an example, we use XRF to assess the accumulation and distribution of metals in the roots of plants growing in urban storm water discharge areas.