The main objective of this project is to examine two important environmental interfaces (mineral-water and biofilm-mineral interfaces) at the molecular level with the aim of understanding the mechanisms by which such interfaces react with and sequester common heavy metal contaminants such as lead and arsenic. Researchers also will examine how microbial biofilms attach to solid surfaces.
Such interfaces dominate much of the chemistry that occurs in the earths biosphere, affecting the weathering of rocks and minerals, the composition and potability of natural waters, the formation of acid rain and acid mine drainage, and the destruction of ozone in the troposphere. Such interfacial reactions are also responsible in large part for the sequestration of environmental contaminants such as heavy metals (e.g., chromium, mercury, and lead) and radionuclides (e.g., uranium and plutonium) and their transformations into more or less toxic or potentially bioavailable forms.
We have used state-of-the-art synchrotron radiation-based spectroscopic and imaging methods to examine the interactions of common soil bacteria with mineral surfaces and with aqueous solutions at nanometer scales, with the aim of developing a mechanistic understanding of the microbiological dissolution of mineral surfaces and biomineralization the process by which biological organisms cause the precipitation of minerals which may sequester toxic elements.