Aging characteristics and reactivity of two types of nanoscale zero-valent iron particles (FeBH and FeH2) in nitrate reduction

Kim, Hong-Seok; Kim, Sang Woo; Ahn, Jaehun; Hwang, Kyung-Yup; Park, Joo-Yang; Lim, Teik−Thye; Hwang, Inseong

doi:10.1016/j.cej.2012.05.018

Cited by 87 publications

(36 citation statements)

References 31 publications

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“…M48h-Al O Cr(VI) removal efficiency is within the range of the values reported for nZVI obtained from borohydride method (Fe ) at similar pH (Li et al 2008 ;Xie and Cwiertny 2012 ;Yu et al 2014 ). This can be considered as a good result: first, because Fe is known to have a higher reactivity than other commercial nZVI products (Kim et al 2012 ) and second, due to the fact that in the present case the batches were not stirred during reaction.…”

Section: Tablesupporting

confidence: 57%

“…In all cases, the Cr(VI) depletion took place mainly within the first 2 h, and subsequent analysis for 2 months did not show significant changes in Cr(VI) concentration. Passivation of nZVI is a frequently reported problem (Kim et al 2012 ;Xie and Cwiertny 2012 ;Liu and Lowry 2006 ;Li et al 2008 ) and in the specific case of Cr(VI) reduction, it seems to be related to the growth of Fe-Cr compounds on the particle surface (Kerkar et al 1990 ).…”

Section: Figmentioning

confidence: 99%

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Improvements in nanoscale zero-valent iron production by milling through the addition of alumina

et al. 2016

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A new milling procedure for a cost-effective production of nanoscale zero-valent iron for environmental remediation is presented. Conventional ball milling of iron in an organic solvent as Mono Ethylene Glycol produces flattened iron particles that are unlikely to break even after very long milling times. With the aim of breaking down these iron flakes, in this new procedure, further milling is carried out by adding an amount of fine alumina powder to the previously milled solution. As the amount of added alumina increases from 9 to 54 g l-1, a progressive decrease of the presence of flakes is observed. In the latter case, the appearance of the particles formed by fragments of former flakes is rather homogeneous, with most of the final nanoparticles having an equivalent diameter well below 1 µm and with an average particle size in solution of around 400 nm. An additional increase of alumina content results in a highly viscous solution showing worse particle size distribution. Milled particles, in the case of alumina concentrations of 54 g l-1, have a fairly large specific surface area and high Fe(0) content. These new particles show a very good Cr(VI) removal efficiency compared with other commercial products available. This good reactivity is related to the absence of an oxide layer, the large amount of superficial irregularities generated by the repetitive fracture process during milling and the presence of a fine nanostructure within the iron nanoparticles.Peer ReviewedPreprin

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Section: Tablesupporting

confidence: 57%

Section: Figmentioning

confidence: 99%

Improvements in nanoscale zero-valent iron production by milling through the addition of alumina

et al. 2016

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“…With regard to nitrate pollution, it has been widely observed that ammonium is the main reduction product in the presence of nZVI, with only a small fraction of nitrite detected; nitrite is regarded as an intermediate (Kim et al, 2012;Sohn et al, 2006;Ahn et al, 2008;Yang and Lee, 2005). Although ammonium is a toxic pollutant to some organisms (do Amaral et al, 2013;Dai et al, 2008Dai et al, , 2012, it serves as major nitrogen source for plants (Fuertes-Mendizabal et al, 2013;Cabezas and Couto, 2007).…”

Section: Introductionmentioning

confidence: 99%

Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

et al. 2014

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a b s t r a c tNanoscale zerovalent iron (nZVI) has demonstrated high efficacy for treating nitrate or cadmium (Cd) contamination, but its efficiency for simultaneous removal of nitrate and Cd has not been investigated. This study evaluated the reactivity of nZVI to the cocontaminants and by-product formation, employed different catalysts to reduce nitrite yield from nitrate, and examined the transformation of nZVI after reaction. Nitrate reduction resulted in high solution pH, negatively charged surface of nZVI, formation of Fe 3 O 4 (a stable transformation of nZVI), and no release of ionic iron. Increased pH and negative charge contributed to significant increase in Cd(II) removal capacity (from 40 mg/g to 188 mg/g) with nitrate present. In addition, nitrate reduction by nZVI could be catalyzed by Cd(II): while 30% of nitrate was reduced by nZVI within 2 h in the absence of Cd(II), complete nitrate reduction was observed in the presence of 40 mg-Cd/L due to the formation of Cd islands (Cd(0) and CdO) on the nZVI particles. While nitrate was reduced mostly to ammonium when Cd(II) was not present or at Cd(II) concentrations ! 40 mg/L, up to 20% of the initial nitrate was reduced to nitrite at Cd(II) concentrations < 40 mg/L. Among nZVI particles doped with 1 wt. % Cu, Ag, or Au, nZVI deposited with 1 wt. % Au reduced nitrite yield to less than 3% of the initial nitrate, while maintaining a high Cd(II) removal capacity.© 2014 Elsevier Ltd. All rights reserved. Available online at www.sciencedirect.com ScienceDirect journal homepage: www.else vier.com/locate /wa tres w a t e r r e s e a r c h 6 3 ( 2 0 1 4 ) 1 0 2 e1 1 1http://dx

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“…It might be due to oxidation during storage or different surface characteristics caused by different synthesis procedures. It was reported that aging of nZVI was significantly dependent on its preparation method [23] and aging conditions [24]. Therefore, in order to apply the commercial nZVI tested in this study on remediation work, the use of extreme conditions, e.g.…”

Section: Determining a Reactivity Of Unknown Nzvi Samplesmentioning

confidence: 99%

Graduated characterization method using a multi-well microplate for reducing reactivity of nanoscale zero valent iron materials

Hwang

Salatas

Mines

et al. 2016

Applied Catalysis B: Environmental

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Aging characteristics and reactivity of two types of nanoscale zero-valent iron particles (FeBH and FeH2) in nitrate reduction

Cited by 87 publications

References 31 publications

Improvements in nanoscale zero-valent iron production by milling through the addition of alumina

Improvements in nanoscale zero-valent iron production by milling through the addition of alumina

Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

Graduated characterization method using a multi-well microplate for reducing reactivity of nanoscale zero valent iron materials

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