Grant: Discovery Grants Program - Individual

Environmental processes involve chemical reactions occurring in the air, the water, soil, and in aquatic sediments (muds at the bottoms of lakes and the oceans). These chemical reactions determine air, water, and soil quality because they can liberate needed micro-nutrients or immobilize toxic metals or decompose harmful compounds. Many of these most important reactions involve newly discovered "environmental nanoparticles" which are small aggregates of reactive substances containing only tens to thousands of atoms. An important class of such environmental nanoparticles are nanoparticles of Fe-oxyhydroxide [Fe is the atomic symbol for iron and an oxyhydroxide is a compound with hydroxyl groups (OH) and water groups (OH2)]. Fe-oxyhydroxides play major roles in water, soils, and sediments, where they control key nutrients and metals by binding with them (when formed by precipitation) and by liberating them (when dissolved under changing conditions of pH, temperature, or oxidation power). We are condensed matter physicists and do not normally study such environmental phenomena but we have theoretical and experimental tools that can be used to study nanoparticulate Fe-oxyhydroxides to great advantage, in order to deduce their structures, compositions, and how they were formed and in order to follow their reactions. We do this by using advanced measurement methods (spectroscopy, diffraction, etc.), by making Fe-oxyhydroxides in the laboratory, and by developing theoretical models of how they form and react. The more we know about Fe-oxyhydroxides, the more we can manage our impacts on soil and water and the more we can devise sustainable practices.