Mineral-Water Inerfacial Processes
Minieral-water interfacial processes, including adsorption, oxidation and precipitation, affect nurient and trace element cycling (e.g., toxic metals) and availability and organic carbon stabilization in soils and sediments. To improve the fundamental understanding of the processes, we use synchrotron X-ray techniques (XANES/EXAFS spectroscopy and atomic pair distribution function analysis) and ultra-high resolution mass spectrometry (e.g., ESI-FT-ICR-MS), as well as surface complexation modeling and quantum chemical calculations, to aquire molecular-scale information. Our current focus in this line of research is on interactions between light oxyanions (sulfate, phosphae and silicate) and natural organic matter with Mn and Fe oxides. The following figures show some of our recent work on phosphate, sulfate and silicate adsorption, polymeization and precipitation on Fe oxide surfaces.