HIGHLIGHTED RESEARCH PROJECTS
In our research we explore the biogeochemical processes occurring at the soil-water-plant interface (ak.a. the Rhizosphere) and how these processes influence the mobility and bioavailability of trace nutrient elements and heavy metals in natural systems. Metals enter the environment from a variety of sources, whether geogenically from metal rich parent materials, or anthropogenically from sources such as metal smelting/refining, military training activities, land application of drinking water or wastewater treatment residues or animal waste applications. Understanding how these metals interact with the numerous inorganic, organic and biological components present within soil is essential to predicting their overall fate and impact on or within the surrounding ecosystem. The intimate association between all of these components makes it difficult to evaluate the chemical and physical processes taking place with just one technique. Therefore, I apply both macroscopic (e.g. stirred-flow dissolution, sequential extraction) and microscopic (SEM, TEM, confocal microscopy) and molecular (XAS) techniques to explore the multiple scales over which these processes are occurring. One of the most innovative techniques is synchrotron based X-ray absorption spectroscopy (XAS). With cutting-edge focusing optics, the X-rays produced at synchrotron facilities can be used to probe metal distributions, correlations and speciation within heterogeneous systems such as soils and plants, in-situ (i.e. with water).