Nano Archive

Reduction of Se(VI) to Se(-II) by zerovalent iron nanoparticle suspensions

Olegario, Jovilynn T. and Yee, Nay and Miller, Marissa and Sczepaniak, John and Manning, Bruce (2010) Reduction of Se(VI) to Se(-II) by zerovalent iron nanoparticle suspensions. Journal of Nanoparticle Research, 12 (6). pp. 2057-2068.

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Abstract

The reaction of selenate (Se(VI)) with zerovalent iron nanoparticles (nano Fe0) was studied using both conventional batch equilibrium and X-ray spectroscopic techniques. Nano Fe0 has a high uptake capacity for removal of dissolved Se(VI) reaching concentrations as high as 0.10 Se:Fe molar ratio in the solid product mixture. Kinetic studies of the Se(VI) uptake reaction in batch experiments showed an initial reaction rate (0–30 min) of 0.0364 min−1 which was four times greater than conventional Fe0 powder. Analysis of the oxidation state of Se in the solid products by X-ray absorption near edge structure (XANES) spectroscopy showed evidence for the reduction of Se(VI) to insoluble selenide (Se(-II)) species. Structural analysis of the product by extended X-ray absorption fine structure (EXAFS) spectroscopy suggested that Se(-II) was associated with nano Fe0 oxidation products as a poorly ordered iron selenide (FeSe) compound. The fitted first shell Se–Fe interatomic distance of 2.402 (±0.004) Å matched closely with previous studies of the products of Se(IV)-treated Fe(II)-clays and zero-valent iron/iron carbide (Fe/Fe3C). The poorly ordered FeSe product was associated with Fe0 corrosion product phases such as crystalline magnetite (Fe3O4) and Fe(III) oxyhydroxide. The results of this investigation suggest that nano Fe0 is a strong reducing agent capable of efficient reduction of soluble Se oxyanions to insoluble Se(-II).

Item Type:Article
Uncontrolled Keywords:Fe nanoparticles - Reduction - Selenium(VI) - Selenium(-II) - SEM - EXAFS - Soils - Radioactive waste
Subjects:Material Science > Nanochemistry
ID Code:9463
Deposited By:SPI
Deposited On:02 Aug 2010 17:24
Last Modified:02 Aug 2010 17:24

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