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Mechanisms of selenium removal by partially oxidized magnetite nanoparticles for wastewater remediation

Börsig, Nicolas 1; Scheinost, Andreas C.; Schild, Dieter ORCID iD icon 2; Neumann, Thomas
1 Institut für Angewandte Geowissenschaften (AGW), Karlsruher Institut für Technologie (KIT)
2 Institut für Nukleare Entsorgung (INE), Karlsruher Institut für Technologie (KIT)

Abstract (englisch):

Magnetite nanoparticles are a promising cost-effective material for the remediation of polluted wastewaters. Due to their magnetic properties and their high adsorption and reduction potential, they are particularly suitable for the decontamination of oxyanion-forming contaminants, including the highly mobile selenium oxyanions sele-nite and selenate. However, little is known how the remediation efficiency of magnetite nanoparticles in field applications is affected by partial oxidation and the formation of magnetite/maghemite phases. Here we char-acterize the retention mechanisms and capacity of partially oxidized nanoparticulate magnetite for selenite and selenate in an oxic system at different pH conditions and ionic strengths. Data from adsorption experiments showed that retention of selenate is extremely limited except for acidic conditions and strongly influenced by competing chloride anions, indicating outer-sphere adsorption. By contrast, although selenite adsorption ca-pacity of oxidized magnetite is also adversely affected by increasing pH, considerable selenite quantities are retained even at alkaline conditions. Using spectroscopic analyses (XPS, XAFS), both mononuclear edge-sharing (2E) and binuclear corner-sharing (2C) inner-sphere selenite surface complexes were detected, while reduction to Se(0) or Se(–II) species could be excluded. ... mehr

Postprint §
DOI: 10.5445/IR/1000136521
Veröffentlicht am 22.12.2022
DOI: 10.1016/j.apgeochem.2021.105062
Zitationen: 6
Web of Science
Zitationen: 3
Zitationen: 6
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Geowissenschaften (AGW)
Institut für Nukleare Entsorgung (INE)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 09.2021
Sprache Englisch
Identifikator ISSN: 0883-2927
KITopen-ID: 1000136521
HGF-Programm 32.11.03 (POF IV, LK 01) Fundamental Scientific Aspects
Erschienen in Applied geochemistry
Verlag Elsevier
Band 132
Seiten Art.-Nr.: 105062
Projektinformation ImmoRad (BMBF, EU 6. RP, 02NUK019B)
GRACE_Ergänzung (HGF, HGF IVF, VH-GS-304_II)
Vorab online veröffentlicht am 28.07.2021
Schlagwörter Selenite; Selenate; Oxyanions; Se(IV); Se(VI); Iron oxides; Maghemite; Adsorption; Immobilization; Retention; XPS; XAFS; XANES; EXAFS
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