原文:
Se K-edge XAFS spectra were collected for various model compounds of Se as well as for 3 biofilm samples
from bioreactors used for Se-contaminated wastewater treatment. In the biofilm samples, Se is dominantly as Se(0)
despite Se K-edge XANES spectroscopy cannot easily distinguish between elemental Se and Se(-I)-bearing selenides.
EXAFS spectra indicate that Se is located within aperiodic domains, markedly different to these known in monoclinc red
selenium. However, Se can well occur within nanodivided domains related to monoclinic red Se, as this form was
optically observed at the rim of some sludges. Aqueous selenate is then efficiently bioreduced, under sulfate reducing
and methanogenic conditions.