Advanced

Reactivity of Fe from a natural stream water towards As(V)

Sundman, Anneli; Karlsson, Torbjorn and Persson, Per LU (2015) In Applied Geochemistry 61. p.185-191
Abstract
Interactions between iron (Fe) and arsenic (As) play a vital role in aquatic and terrestrial ecosystems influencing the reactivity and transport of arsenic. A key aspect is the effect of natural organic matter (NOM) on these interactions, and previous investigations have reported the existence of ternary As-Fe-NOM species. In this study, the reactivity of Fe, from a boreal stream water, towards As(V) was investigated using Fe and As K-edge X-ray absorption spectroscopy (XAS). The native stream water was shown to contain mononuclear Fe-NOM complexes together with Fe(III) (hydr) oxides associated with the NOM. Addition of As(V) to this water at Fe to As ratios of 2.0-15.6 resulted in substantial changes in the Fe speciation; the Fe(III)... (More)
Interactions between iron (Fe) and arsenic (As) play a vital role in aquatic and terrestrial ecosystems influencing the reactivity and transport of arsenic. A key aspect is the effect of natural organic matter (NOM) on these interactions, and previous investigations have reported the existence of ternary As-Fe-NOM species. In this study, the reactivity of Fe, from a boreal stream water, towards As(V) was investigated using Fe and As K-edge X-ray absorption spectroscopy (XAS). The native stream water was shown to contain mononuclear Fe-NOM complexes together with Fe(III) (hydr) oxides associated with the NOM. Addition of As(V) to this water at Fe to As ratios of 2.0-15.6 resulted in substantial changes in the Fe speciation; the Fe(III) (hydr) oxides were partly converted into FeAsO4(s) or a solid solution where As(V) was incorporated into Fe(III) (hydr) oxide structures. Under the same conditions no or only small effects of As(V) on the Fe-NOM complexes initially present were observed, and the concurrent existence of these complexes and free As(V) showed that a large fraction of the Fe-NOM complexes were non-reactive towards As(V). This study suggests that complexation of Fe by NOM in organic rich environments may lead to elevated free, aqueous arsenic levels as these complexes do not interact with As(V). Moreover, the formation of Fe-NOM complexes also reduce the tendency of Fe to form reactive Fe(III) (hydr) oxides particles and Fe(III)-arsenate precipitates. (C) 2015 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Applied Geochemistry
volume
61
pages
185 - 191
publisher
Elsevier
external identifiers
  • wos:000360654200016
  • scopus:84935835792
ISSN
0883-2927
DOI
10.1016/j.apgeochem.2015.05.023
project
MICCS - Molecular Interactions Controlling soil Carbon Sequestration
language
English
LU publication?
yes
id
11d07927-6fcf-4aa1-b077-935ef393b945 (old id 8077474)
date added to LUP
2015-10-26 13:49:15
date last changed
2017-01-01 03:30:31
@article{11d07927-6fcf-4aa1-b077-935ef393b945,
  abstract     = {Interactions between iron (Fe) and arsenic (As) play a vital role in aquatic and terrestrial ecosystems influencing the reactivity and transport of arsenic. A key aspect is the effect of natural organic matter (NOM) on these interactions, and previous investigations have reported the existence of ternary As-Fe-NOM species. In this study, the reactivity of Fe, from a boreal stream water, towards As(V) was investigated using Fe and As K-edge X-ray absorption spectroscopy (XAS). The native stream water was shown to contain mononuclear Fe-NOM complexes together with Fe(III) (hydr) oxides associated with the NOM. Addition of As(V) to this water at Fe to As ratios of 2.0-15.6 resulted in substantial changes in the Fe speciation; the Fe(III) (hydr) oxides were partly converted into FeAsO4(s) or a solid solution where As(V) was incorporated into Fe(III) (hydr) oxide structures. Under the same conditions no or only small effects of As(V) on the Fe-NOM complexes initially present were observed, and the concurrent existence of these complexes and free As(V) showed that a large fraction of the Fe-NOM complexes were non-reactive towards As(V). This study suggests that complexation of Fe by NOM in organic rich environments may lead to elevated free, aqueous arsenic levels as these complexes do not interact with As(V). Moreover, the formation of Fe-NOM complexes also reduce the tendency of Fe to form reactive Fe(III) (hydr) oxides particles and Fe(III)-arsenate precipitates. (C) 2015 Elsevier Ltd. All rights reserved.},
  author       = {Sundman, Anneli and Karlsson, Torbjorn and Persson, Per},
  issn         = {0883-2927},
  language     = {eng},
  pages        = {185--191},
  publisher    = {Elsevier},
  series       = {Applied Geochemistry},
  title        = {Reactivity of Fe from a natural stream water towards As(V)},
  url          = {http://dx.doi.org/10.1016/j.apgeochem.2015.05.023},
  volume       = {61},
  year         = {2015},
}