Deutsch
 
Datenschutzhinweis Impressum
  DetailsucheBrowse

Datensatz

 
 
DownloadE-Mail
  Direct Visualization of Arsenic Binding on Green Rust Sulfate

Perez, J., Freeman, H., Brown, A. P., van Genuchten, C. M., Dideriksen, K., S’ari, M., Tobler, D. J., Benning, L. G. (2020): Direct Visualization of Arsenic Binding on Green Rust Sulfate. - Environmental Science and Technology, 54, 6, 3297-3305.
https://doi.org/10.1021/acs.est.9b07092

Item is

Externe Referenzen

einblenden:

Urheber

einblenden:
ausblenden:
 Urheber:
Perez, J.P.H.1, Autor              
Freeman, Helen1, Autor              
Brown, Andy P.2, Autor
van Genuchten, Case M.2, Autor
Dideriksen, Knud2, Autor
S’ari, Mark2, Autor
Tobler, Dominique J.2, Autor
Benning, Liane G.1, Autor              
Affiliations:
13.5 Interface Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, ou_754888              
2External Organizations, ou_persistent22              

Inhalt

einblenden:
ausblenden:
Schlagwörter: -
 Zusammenfassung: “Green rust” (GR), a redox-active Fe(II)–Fe(III) layered double hydroxide, is a potential environmentally relevant mineral substrate for arsenic (As) sequestration in reduced, subsurface environments. GR phases have high As uptake capacities at circum-neutral pH conditions, but the exact interaction mechanism between the GR phases and As species is still poorly understood. Here, we documented the bonding and interaction mechanisms between GR sulfate and As species [As(III) and As(V)] under anoxic and circum-neutral pH conditions through scanning transmission electron microscopy (STEM) coupled with energy-dispersive X-ray (EDX) spectroscopy and combined it with synchrotron-based X-ray total scattering, pair distribution function (PDF) analysis, and As K-edge X-ray absorption spectroscopy (XAS). Our highly spatially resolved STEM–EDX data revealed that the preferred adsorption sites of both As(III) and As(V) are at GR crystal edges. Combining this data with differential PDF and XAS allowed us to conclude that As adsorption occurs primarily as bidentate binuclear (2C) inner-sphere surface complexes. In the As(III)-reacted GR sulfate, no secondary Fe–As phases were observed. However, authigenic parasymplesite (ferrous arsenate nanophase), exhibiting a threadlike morphology, formed in the As(V)-reacted GR sulfate and acts as an additional immobilization pathway for As(V) (∼87% of immobilized As). We demonstrate that only by combining high-resolution STEM imaging and EDX mapping with the bulk (differential) PDF and extended X-ray absorption fine structure (EXAFS) data can one truly determine the de facto As binding nature on GR surfaces. More importantly, these new insights into As–GR interaction mechanisms highlight the impact of GR phases on As sequestration in anoxic subsurface environments.

Details

einblenden:
ausblenden:
Sprache(n):
 Datum: 2020-02-202020
 Publikationsstatus: Final veröffentlicht
 Seiten: -
 Ort, Verlag, Ausgabe: -
 Inhaltsverzeichnis: -
 Art der Begutachtung: -
 Identifikatoren: DOI: 10.1021/acs.est.9b07092
GFZPOF: p3 PT3 Earth Surface and Climate Interactions
 Art des Abschluß: -

Veranstaltung

einblenden:

Entscheidung

einblenden:

Projektinformation

einblenden:

Quelle 1

einblenden:
ausblenden:
Titel: Environmental Science and Technology
Genre der Quelle: Zeitschrift, SCI, Scopus
 Urheber:
Affiliations:
Ort, Verlag, Ausgabe: -
Seiten: - Band / Heft: 54 (6) Artikelnummer: - Start- / Endseite: 3297 - 3305 Identifikator: CoNE: https://gfzpublic.gfz-potsdam.de/cone/journals/resource/journals130
Publisher: American Chemical Society (ACS)