Infrared spectroscopic and X-ray diffraction characterization of the nature of adsorbed arsenate on ferrihydrite

Jia, Yongfeng; Xu, Lu; Wang, Xin; Demopoulos, George P.

doi:10.1016/j.gca.2006.12.021

Cited by 301 publications

(146 citation statements)

References 43 publications

(93 reference statements)

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“…However, when the reaction time was 5 h or later, the precipitates on the surface of scorodite particles were formed directly by coprecipitation of Fe(III) and As(V) ions. According to this fact, As ions present in the surface area of the particles would be located in the lattice of scorodite with different crystallinity though the resultant value of As composition on the surface was similar at the reaction time of 1 and 7 h. On the other hand, it is known that arsenate ions can be adsorbed on fine ferric oxides; [9][10][11][12][13][14][15] hence, the fine particles formed on the scorodite particles' surfaces were partially such ferric oxides and may act as adsorption sites for the arsenate ions. The formation of ferric oxides implies that the concentration of Fe(III) in the solution is higher than that of As(V), although the ferric oxides are not identified by the XRD measurements.…”

Section: Surface Composition Of Scorodite Particlesmentioning

confidence: 99%

“…Thus far, several studies have been conducted on the solubility and stability of ferric arsenate compounds in water [1][2][3][4][5] and on the dissolution of As from ferric arsenate compounds. [5][6][7] Fundamental studies on E-pH diagrams of arsenic relevant systems 8) and experimental studies on adsorption characteristics of arsenate on ferric compounds [9][10][11][12][13][14][15] have also been conducted. These studies show that the chemical and physical properties of As, such as solubility and adsorption, strongly depend on the structure and morphology of ferric arsenate compounds, which may be controlled by their synthesis routes.…”

Section: Introductionmentioning

confidence: 99%

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Coprecipitation of Large Scorodite Particles from Aqueous Fe(II) and As(V) Solution by Oxygen Injection

Shinoda

Tanno

Fujita³

et al. 2009

Mater. Trans.

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A novel method for synthesizing large scorodite (FeAsO 4 . 2H 2 O) particles was recently developed for the fixation of arsenic. This method involves the coprecipitation of scorodite particles from an Fe(II) and As(V) aqueous solution at approximately 95 C by oxygen injection. In order to understand the process of coprecipitation of scorodite particles by this method, X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used for characterizing reaction products extracted from the suspension during the reaction. The SEM observation showed that the formation of large scorodite particles was almost completed after a reaction time of 3 h, and then, fine particles precipitated on the large particles by further reactions. The XRD results indicated that scorodite particles with specific lattice parameters were formed in the reaction. The XPS results indicated that the arsenic composition on the surface of the scorodite particles decreased until 3 h from the start of precipitation reaction and increased thereafter. These results correspond to the results on the morphology of the scorodite particles obtained by SEM. Furthermore, X-ray absorption spectra (XAS) in the range of X-ray absorption near edge structure (XANES) were measured for gel-like reaction products formed in the initial stages of the reaction. The spectra revealed that the gel-like reaction products were composed of Fe(II) and Fe(III). The coprecipitation of scorodite particles synthesized by the novel method is discussed on the basis of these results together with previous results on the analyses of iron and arsenic concentrations in solution.

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Section: Surface Composition Of Scorodite Particlesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Coprecipitation of Large Scorodite Particles from Aqueous Fe(II) and As(V) Solution by Oxygen Injection

Shinoda

Tanno

Fujita³

et al. 2009

Mater. Trans.

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“…The band at 1676cm -1 is assigned to the O-H bending mode of water, whereas the other O-H stretching bands are in the region 3000-3400cm -1 . The broad stretching of the bands in this region is due to adsorbed or lattice water (Liu et al, 2009;Jia et al, 2007;Kahani and Jafari, 2009). a b Figure 3.…”

Section: Characterization Of Cnt and Cnt-ferrihydrite Compositementioning

confidence: 99%

“…The FTIR spectrum of CNT-ferrihydrite sample loaded with arsenic ( Figure 11) shows that, in addition to all the bands relating to the unloaded sample (Figure 3), it contained an additional band at 803.2cm -1 , which is assigned to the As-O stretching vibration (Jia et al, 2007).…”

Section: Characterisation Of As(v) Loaded Cnt-ferrihydrite Compositementioning

confidence: 99%

Preparation, characterization and As(V) adsorption behaviour of CNT-ferrihydrite composites

Poinern¹,

Parsonage²,

Issa³

et al. 2011

Int. J. Eng. Sci. Tech

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A Carbon nano tube (CNT)-Ferrihydrite nanocomposite was synthesized through precipitation in ethyl alcohol media. Its detailed characterization was carried out using XRD, SEM, FTIR and EDAX. The adsorption characteristics of the composite for As(V) removal were carried out as function of pH, adsorbent dose, As(V) concentration and contact time. Although pure CNT did not show any significant adsorption, CNT-Ferrihydrite proved to be a good adsorbent for arsenic. With increase in pH, the As(V) adsorption on the composite first decreased up to pH 5.0, thereafter it remained nearly constant. The adsorption followed the Langmuir isotherm model and from the data its monolayer adsorption capacity was estimated to be 44.1 mg/g. The adsorption data were best described by the pseudo-second order kinetic model.

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“…Infrared (IR) spectra is particular useful to explore protonation of reactants which significantly influence their chemical reactivity and adsorption mechanism at solid/ liquid interfaces. Previous studies have indicated that the IR vibrational spectra of arsenate on several minerals (such as goethite, ferrihydrite and anatase) contain abundant coordination information [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Combined DFT and IR evidence on metastable-equilibrium adsorption of arsenate on TiO2 surfaces

Zhang

Pan

2009

Journal of Colloid and Interface Science

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Infrared spectroscopic and X-ray diffraction characterization of the nature of adsorbed arsenate on ferrihydrite

Cited by 301 publications

References 43 publications

Coprecipitation of Large Scorodite Particles from Aqueous Fe(II) and As(V) Solution by Oxygen Injection

Coprecipitation of Large Scorodite Particles from Aqueous Fe(II) and As(V) Solution by Oxygen Injection

Preparation, characterization and As(V) adsorption behaviour of CNT-ferrihydrite composites

Combined DFT and IR evidence on metastable-equilibrium adsorption of arsenate on TiO2 surfaces

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