A method has been developed for quantitative analysis of all major sulfur forms in coal, both organic and inorganic, from sulfur K-edge X-ray absorption fine structure (XAFS) spectroscopy. The method is based on least-squares analysis of the X-ray absorption near-edge structure, or XANES, into a series of peaks that represent Isnp photoelectron transitions. Because the major sulfur forms occurring in coal (pyrite, organic sulfide, thiophene, sulfoxide, sulfone, and sulfate) have characteristic s -*• p transition energies, the relative peak area contributed to the XANES by each sulfur form can be determined. These peak areas are converted to weight percentages of sulfur by using calibration constants derived from XANES data from standard compound mixtures. This method has been

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Many current treatments for the reclamation of contaminated water sources are chemical-intensive, energy-intensive, and/or require posttreatment due to unwanted by-product formation. We demonstrate that through the integration of nanostructured materials, enzymatic catalysis, and iron-catalyzed free radical reactions within pore-functionalized synthetic membrane platforms, we are able to conduct environmentally important oxidative reactions for toxic organic degradation and detoxification from water without the addition of expensive or harmful chemicals. In contrast to conventional, passive membrane technologies, our approach utilizes two independently controlled, nanostructured membranes in a stacked configuration for the generation of the necessary oxidants. These include biocatalytic and organic/inorganic (polymer/ iron) nanocomposite membranes. The bioactive (top) membrane contains an electrostatically immobilized enzyme for the catalytic production of one of the main reactants, hydrogen peroxide (H 2 O 2 ), from glucose. The bottom membrane contains either immobilized iron ions or ferrihydrite/iron oxide nanoparticles for the decomposition of hydrogen peroxide to form powerful free radical oxidants. By permeating (at low pressure) a solution containing a model organic contaminant, such as trichlorophenol, with glucose in oxygen-saturated water through the membrane stack, significant contaminant degradation was realized. To illustrate the effectiveness of this membrane platform in real-world applications, membrane-immobilized ferrihydrite/iron oxide nanoparticles were reacted with hydrogen peroxide to form free radicals for the degradation of a chlorinated organic contaminant in actual groundwater. Although we establish the development of these nanostructured materials for environmental applications, the practical and methodological advances demonstrated here permit the extension of their use to applications including disinfection and/or virus inactivation.enzyme catalysis | functionalized membranes | pollutant | microfiltration | responsive materials

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X-ray absorption fine structure spectroscopy has been used to determine directly the oxidation states and speciation of selenium and arsenic in 10 fly ash samples collected from full-scale utility plants. Such information is needed to assess the health risk posed by these elements in fly ash and to understand their behavior during combustion and in fly ash disposal options, such as sequestration in tailings ponds. Selenium is found predominantly as Se(IV) in selenite (SeO3(2-)) species, whereas arsenic is found predominantly as As(V) in arsenate (AsO4(3-)) species. Two distinct types of selenite and arsenate spectra were observed depending upon whether the fly ash was derived from eastern U.S. bituminous (Fe-rich) coals or from western subbituminous or lignite (Ca-rich) coals. Similar spectral details were observed for both arsenic and selenium in the two different types of fly ash, suggesting that the postcombustion behavior and capture of both of these elements are likely controlled by the same dominant element or phase in each type of fly ash.

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