Speciation and oxidation reaction analysis of selenium in aqueous solution using X-ray absorption spectroscopy for management of trace element in FGD liquor

► XAS analysis is performed using aqueous solutions containing Se(IV) and Se(VI). ► Valance states of Se are specified easily and clearly by XAS analysis. ► Local structure of centered Se atoms can be identified even at 10 mg-Se/L. ► In situ XAS spectra during the Se oxidation have a high quantitative capability. ► XAS analysis can be applied for behavior elucidation of trace elements.