es8b02101_si_001.pdf (1.39 MB)
Adsorption and Incorporation of Arsenic to Biogenic Lepidocrocite Formed in the Presence of Ferrous Iron during Denitrification by Paracoccus denitrificans
journal contribution
posted on 2018-08-15, 00:00 authored by Sunhwa Park, Ji-Hoon Lee, Tae Joo Shin, Hor-Gil Hur, Min Gyu KimWe
demonstrate adsorption and partial incorporation of arsenic,
in its soluble form, either as arsenite or arsenate into lepidocrocite
(γ-FeOOH), which was formed through nitrite-driven Fe(II) oxidation
by Paracoccus denitrificans under nitrate-reducing
conditions. Fe and As K-edge XANES and radial distribution functions
of Fourier-transformed EXAFS spectra showed that portions of As were
found to be incorporated in the biogenic lepidocrocite, in addition
to higher portions of adsorbed As. We suggest that denitrifying bacteria
such as Paracoccus denitrificans, studied here, could
facilitate decrease of aqueous arsenic As(III) and/or As(V) through
indirect Fe(II) oxidation to solid phase iron minerals, here as lepidocrocite,
by the denitrification product nitrite in the presence of nitrate,
ferrous iron, and arsenic, under certain environmental conditions
where these materials could be found, such as in As-contaminated paddy
soils and wetlands.