Goethite as an antimony host-phase: Atomic-scale retention mechanisms and the selectivity of commonly-applied extraction schemes

Mona Hosseinpour Moghaddam; Niloofar Karimian; Scott G. Johnston; Girish Choppala; Mohammad Rastegari; Edward D. Burton

doi:10.1016/j.jhazmat.2026.141097

Goethite as an antimony host-phase: Atomic-scale retention mechanisms and the selectivity of commonly-applied extraction schemes

Mona Hosseinpour Moghaddam, Niloofar Karimian, Scott G. Johnston, Girish Choppala, Mohammad Rastegari Edward D. Burton

Journal of hazardous materials, Vol.503, pp.1-13

02/2026

: https://doi.org/10.1016/j.jhazmat.2026.141097

: 41534282

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Goethite as an antimony host-phase5.33 MB

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Goethite as an antimony host-phase

Published (Version of record),

adsorption

Antimonate

coprecipitation

EXAFS

sequential extraction

Goethite (α-FeOOH) is one of the most important host-phases for Sb(V) in soils, sediments and geogenic wastes. This study examines, for the first time, how variability in the atomic-scale mechanisms of Sb(V) retention by goethite impacts the selectivity of commonly-applied Sb extraction schemes. EXAFS spectroscopy shows that Sb(V) retention via coprecipitation involves Sb(V) incorporation into goethite’s structure through Sb(V)-for-Fe(III) substitution. In contrast, Sb(V) retention via sorption involves edge and double-corner sharing between SbO₆ and FeO₆ octahedra at the goethite surface. Incorporation of Sb(V) into goethite's structure causes Sb(V) to be largely inaccessible to 1M HCl, steps 1, 2 and 3 of Wenzel et al.'s sequential extraction scheme and all 3 steps of the BCR extraction scheme. In contrast, Sb(V) sorption to goethite's surface facilitates more substantial Sb(V) extractability, which varies with the relative abundance of SbO₆-FeO₆ linkages. Importantly, Sb(V) sorption to the goethite surface is underestimated by both the Wenzel et al. and BCR schemes. In addition, the BCR scheme misidentifies a significant portion of goethite-sorbed Sb(V) as oxidisable phases (e.g. sulfides or organic matter). Hence, in soils, sediments or geogenic wastes where Sb(V) is sorbed to goethite, the BCR scheme is not appropriate for quantifying Sb(V) fractionation. Overall, our results demonstrate that variability in the atomic-scale mechanisms by which goethite retains Sb(V) translate to substantial complexity in Sb(V) extractability.

: Goethite as an antimony host-phase: Atomic-scale retention mechanisms and the selectivity of commonly-applied extraction schemes
: Mona Hosseinpour Moghaddam - Southern Cross University
Niloofar Karimian - Monash University
Scott G. Johnston - Southern Cross University
Girish Choppala - University of Newcastle Australia
Mohammad Rastegari - Southern Cross University
Edward D. Burton - Southern Cross University
: Journal of hazardous materials, Vol.503, pp.1-13
: Elsevier B.V.
: This research was supported by the Australian Research Council (Project FT200100449) and by additional financial assistance from Southern Cross University.
: 991013344086702368
: Faculty of Science and Engineering; Science
: English
: Journal article