Brandy Toner

My research addresses chemical and biological processes that result in the cycling of metals in the environment. I approach these processes from the perspective of metal speciation: What is the form of the metal, and how will its form affect transport, fate, and bioavailability. My favorite metals are iron (Fe) and manganese (Mn). These two transition metals are prevalent in terrestrial and aquatic environments. They both form chemically reactive minerals – Fe oxyhydroxides and Mn oxides –  that influence, and sometimes control, the partitioning of other elements, like arsenic (As) between the solid and aqueous phases. Iron and Mn are also interesting study subjects because microbial activity can make their speciation delightfully complex.