Properties of impurity-bearing ferrihydrite III. Effects of Si on the structure of 2-line ferrihydrite

Cismasu, A. Cristina; Michel, F. Marc; Tcaciuc, A. Patricia; Brown, Gordon E.

doi:10.1016/j.gca.2014.02.018

Cited by 74 publications

(55 citation statements)

References 66 publications

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“…This band may be indicative for monomeric silicate, which bonds to Fe polymers and ferrihydrite particles at Si contents as low as observed in our study (~5 mol%; Cismasu et al (2014)). The band vanished in the spectra of Ah_3+4, in which the Fe-OM co-precipitates contained the lowest Si content ( Figure 1D).…”

Section: Elemental Composition Of the Fe-om Co-precipitatessupporting

confidence: 54%

“…Such lattice distortions arise due to the presence of foreign ligands other than O and OH, e.g. DOM (Eusterhues et al, 2008), Al (Cismasu et al, 2012), Si (Cismasu et al, 2014) and P (Voegelin et al, 2010). The broad distribution of ∆E Q indicates the coexistence of different Fe(III) environments in the Fe-OM co-precipitates, each with a characteristic degree of lattice distortion.…”

Section: Structural Changes In the Fe-om Co-precipitates At Transientmentioning

confidence: 99%

“…A high proportion of surface-near Fe sites would also contribute to the pronounced tailing at higher ∆E Q as observed in our study (Figure 2A,C), provided that the crystallite sizes of the Fe-OM co-precipitates are comparably small. Referring to Fe oxide precipitation experiments with DOM (Eusterhues et al, 2008), Si (Cismasu et al, 2014) and As (Erbs et al, 2010;Rancourt et al, 2001), small crystallite sizes can be assumed for the Fe-OM coprecipitates in our study. The absence of distinct reflexes in the X-ray diffractograms indicates the absence of enhanced scattering domains and therefore supports this assumption ( Figure EA-14).…”

Section: Structural Changes In the Fe-om Co-precipitates At Transientmentioning

confidence: 99%

“…Soil OM (Schwertmann, 1966), P (Châtellier et al, 2013), Al (Masue-Slowey et al, 2011), silicate (Cismasu et al, 2014) and As (Ford, 2002) are known to stabilize Fe polyhedra in very primitive arrangements, i.e. low-crystalline ferrihydrite.…”

Section: Structural Changes In the Fe-om Co-precipitates At Transientmentioning

confidence: 99%

“…Such studies include silicate (Cismasu et al, 2014), calcium, phosphate and arsenate/arsenite in the absence and in presence of silicate (van Genuchten et al, 2014;Voegelin et al, 2010;respectively), polysaccharides (Mikutta et al, 2008), proteins (Kashyap et al, 2014) and dissolved organic matter (OM) from forest floor layers (Eusterhues et al, 2008;Mikutta et al, 2014b). While these studies provide important insights into the impact of single compounds on the Fe oxide properties, it remains unclear to what extent these findings apply to Fe oxides that precipitate in natural systems.…”

Section: Introductionmentioning

confidence: 99%

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Structure and composition of Fe–OM co-precipitates that form in soil-derived solutions

Fritzsche

Schröder

Wieczorek

et al. 2015

Geochimica et Cosmochimica Acta

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Iron oxides represent a substantial fraction of secondary minerals and particularly affect the reactive properties of natural systems in which they formed, e.g. in soils and sediments. Yet, it is still obscure how transient conditions in the solution will affect the properties of in situ precipitated Fe oxides. Transient compositions, i.e. compositions that change with time, arise due to predominant non-equilibrium states in natural systems, e.g. between liquid and solid phases in soils. In this study, we characterize Fe-OM co-precipitates that formed in pH-neutral exfiltrates from anoxic topsoils under transient conditions. We applied soil column outflow experiments, in which Fe 2+ was discharged with the effluent from anoxic soil and subsequently oxidized in the effluent due to contact with air. Our study features three novel aspects being unconsidered so far: 3

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Section: Elemental Composition Of the Fe-om Co-precipitatessupporting

confidence: 54%

Section: Structural Changes In the Fe-om Co-precipitates At Transientmentioning

confidence: 99%

Section: Structural Changes In the Fe-om Co-precipitates At Transientmentioning

confidence: 99%

Section: Structural Changes In the Fe-om Co-precipitates At Transientmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Structure and composition of Fe–OM co-precipitates that form in soil-derived solutions

Fritzsche

Schröder

Wieczorek

et al. 2015

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

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Nanomaterials as Source of Environmental Contaminants: From Exposure to Preventive Interventions

Kamal¹,

Junaid²,

Bibi

et al. 2021

Emerging Contaminants and Associated Treatment Technologies

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The influence of silicate on transformation pathways of synthetic 2-line ferrihydrite

Rzepa

Pieczara

Gaweł

et al. 2016

J Therm Anal Calorim

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In this study, a series of synthetic ferrihydrite samples of Si/Fe molar ratios ranging from zero to 1.5 were heated up to 1000°C using simultaneous TG-DTA equipment. The XRD, FTIR, SEM-EDS and magnetic susceptibility measurements were carried out prior to and after heating. It has been found that silicate retards ferrihydrite transformation to hematite and affects crystallinity of the product. Low Si admixture in the precursor reduces hematite crystal size severely, but the increase in average crystal dimensions with increasing Si/Fe molar ratio was observed. High Si content results in the formation of hematite which exhibits a wide range of crystal habits. The conversion of pure ferrihydrite to hematite proceeds without any intermediate phase, whereas the increasing silicate content in the pristine oxyhydroxide strongly affects the transformation pathway. During annealing of high-Si ferrihydrites, the presence of two or three intermediate Fe 2 O 3 polymorphs (gamma, epsilon and beta) was demonstrated prior to the crystallization of final a-Fe 2 O 3 . The conditions favoring crystallization of intermediate phases result from progressive silica polymerization which forms separate matrix-type phase and impedes the aggregation of iron oxide nanoparticles.

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Properties of impurity-bearing ferrihydrite III. Effects of Si on the structure of 2-line ferrihydrite

Cited by 74 publications

References 66 publications

Structure and composition of Fe–OM co-precipitates that form in soil-derived solutions

Structure and composition of Fe–OM co-precipitates that form in soil-derived solutions

Nanomaterials as Source of Environmental Contaminants: From Exposure to Preventive Interventions

The influence of silicate on transformation pathways of synthetic 2-line ferrihydrite

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