Chang, Fang-Ru C. EAR-9504813 The Fellow will study mechanisms of trace metal adsorption and desorption by clay minerals in the presence of competing cations and chelating agents. Synchrotron radiation based X-ray absorption spectroscopic studies will be used to investigate the interactions between surface functional groups of clay minerals and aqueous species in the interfacial region. Results of this study will improve our understanding of biogeochemical weathering and dissolution of clay minerals. The study will provide molecular level information that will be useful for refining solute transport models, and it may also shed new light on phytoremediation techniques. The application of XAS to characterize metal adsorption sites on clays is an important application of this new technique; the more common empirical models of adsorption/desorption are no substitute of solid structural information. This opportunity allows the Fellow to master a new technique, combine it with her established strength in clay chemistry, and make solid contributions to a societally relevant problem.
