Environmental interfaces, heavy metals, microbes, and plants: applications of XAFS spectroscopy and related synchrotron radiation methods to environmental science

During the past decade, applications of synchrotron radiation (SR) methods to environmental science have grown significantly, resulting in a new interdisciplinary field known as molecular environmental science, which focuses on the molecular-level speciation of environmental pollutants and the fundamental chemical and biological processes determining their behavior in complex systems. Here we review some recent applications of XAFS spectroscopy and related SR methods, including micro-XANES and X-ray Standing Wave (XSW) spectroscopy, micro-XRD, X-ray fluorescence micro-tomography, and photoemission spectroscopy to heavy metals and actinides in model systems and more complex environmental samples. Examples include XAFS studies of heavy metals and actinides at environmental interfaces, combined XAFS and XSW studies of heavy metal interactions with microbial biofilm-coated metal oxide surfaces, and combined XANES and photoemission studies of microbial interactions with metal sulfide surfaces.