Sorption of selenium(IV) and selenium(VI) to mackinawite (FeS): Effect of contact time, extent of removal, sorption envelopes

Han, Dong Suk; Batchelor, Bill; Abdel‐Wahab, Ahmed

doi:10.1016/j.jhazmat.2010.11.017

Cited by 65 publications

(32 citation statements)

References 34 publications

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“…Moreover, the enrichment capacity of FeS was also affected by solution pH because the hydroxyl and bisulfide functional groups on FeS surfaces would undergo different protonation-deprotonation reactions as solution pH changes. 25 Similar phenomena were confirmed by other studies, such as those on UĲVI), 5,9,26 SeĲIV) and SeĲVI), 23 and HgĲII), 12 and organic contaminants. 25 Hua and Deng 5 also found that the uptake of UĲVI) from aqueous solution by amorphous FeS was quick and the sorption equilibrium was achieved within 1 h. The experimental data were analyzed by using pseudo-firstorder kinetic models (ln(q e − q t ) = ln q e − k 1 t, where q e and q t are the maximum and the experimental enrichment capacity, respectively; K 1 (h −1 ) is the rate constant of enrichment) and pseudo-second-order kinetic models Ĳt/C s = 1/Ĳ2K′ĴC ′ s ) + t/C ′ s , where C ′ s (mg g −1 ) is the enrichment capacity; K′ (g mg −1 h −1 ) is the rate constant of enrichment).…”

Section: Enrichment Capability Of Paam-fes/fe 3 O 4 Compositessupporting

confidence: 89%

“…23 Herein, the correlation coefficients (R 2 ) ( Table 1) indicated that the experimental data could be better described by the Langmuir model than by the Freundlich model. The applicability of the Langmuir model suggested that PAAM/Fe 3 O 4 and PAAM-FeS/Fe 3 O 4 surfaces were uniform and homogeneous for UĲVI) sorption.…”

Section: Enrichment Capability Of Paam-fes/fe 3 O 4 Compositesmentioning

confidence: 90%

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Reductive immobilization of uranium by PAAM–FeS/Fe₃O₄ magnetic composites

Shao

Wang

et al. 2015

Environ. Sci.: Water Res. Technol.

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Ternary magnetic composites of polyĲacrylamide)-stabilized FeS/Fe 3 O 4 (denoted as PAAM-FeS/Fe 3 O 4 ) were in situ synthesized by chemical coprecipitation of FeS/Fe 3 O 4 in the presence of acrylamide (AAM), followed by dielectric barrier discharge (DBD) plasma-induced polymerization of AAM on the FeS/Fe 3 O 4 surface. The modified PAAM improved greatly the stabilization and dispersion properties of PAAM-FeS/Fe 3 O 4 in aqueous solutions. This as-prepared composite was applied as an adsorbent for the preconcentration of UĲVI) cations from aqueous solutions. The maximum enrichment capacity of UĲVI) on this adsorbent at pH 5.0 and 20°C was calculated to be 311 mg g −1 . The presence of other cations had no obvious influence on the sorption of UĲVI) on PAAM-FeS/Fe 3 O 4 , suggesting that this absorbent can remove UĲVI) with high selectivity. According to the results of XPS spectra analysis, both FeS and amide groups on PAAM-FeS/Fe 3 O 4 surfaces have strong chemical affinities to UĲVI), and FeS can also reduce UĲVI) to UĲIV) effectively. The coagulation of magnetic U-laden PAAM-FeS/Fe 3 O 4 can be easily separated and recovered from aqueous solution by simple magnet separation. This paper highlights the potential application of PAAM-FeS/Fe 3 O 4 composites as suitable materials for the preconcentration and extraction of trace UĲVI) ions from aqueous solutions in environmental radioactive pollution control and peaceful utilization of nuclear energy, such as the extraction of trace UĲVI) ions from seawater.

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Section: Enrichment Capability Of Paam-fes/fe 3 O 4 Compositessupporting

confidence: 89%

Section: Enrichment Capability Of Paam-fes/fe 3 O 4 Compositesmentioning

confidence: 90%

Reductive immobilization of uranium by PAAM–FeS/Fe₃O₄ magnetic composites

Shao

Wang

et al. 2015

Environ. Sci.: Water Res. Technol.

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“…The inertness of aqueous Se(VI) on iron sulfides is in line with previous studies. 38,39 Possible reasons for the inertness of selenate are discussed in more detail in a companion paper (in preparation).…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Nanocomposite Pyrite–Greigite Reactivity toward Se(IV)/Se(VI)

Charlet

Kang

Bardelli

et al. 2012

Environ. Sci. Technol.

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A nanopyrite/greigite composite was synthesized by reacting FeCl(3) and NaHS in a ratio of 1:2 (Wei et al. 1996). Following this procedure, the obtained solid phases consisted of 30-50 nm sized particles containing 28% of greigite (Fe(2+)Fe(3+)(2)S(4)) and 72% pyrite (FeS(2)). Batch reactor experiments were performed with selenite or selenate by equilibrating suspensions containing the nanosized pyrite-greigite solid phase at different pH-values and with or without the addition of extra Fe(2+). XANES-EXAFS spectroscopic techniques revealed, for the first time, the formation of ferroselite (FeSe(2)) as the predominant reaction product, along with elemental Se. In the present experimental conditions, at pH 6 and in equilibrium with Se(0), the solution is oversaturated with respect to ferrosilite. Furthermore, thermodynamic computations show that reaction kinetics likely played a significant role in our experimental system.

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“…Wild life in ecosystems can be strongly impacted by this release, coming from drain waters, sewage sludge, oil refineries or mining for instance [1]. Sporadic episodes of high concentration release have sometimes led to very harmful levels, with concentrations in drainage water approaching 140-1400 g L −1 [2]. To understand the mobility of selenium species in the environment and to propose remediation processes, it is of high importance to properly describe and understand the nature of the chemical bonds between solid materials (minerals of soils or specifically designed sorbent materials) and selenium species present in aqueous conditions.…”

Section: Introductionmentioning

confidence: 99%

“…In natural aqueous environments, selenium can be found under two stable oxidation states: Se(IV), generally as a selenite oxyanion SeO 3 2− or in its protonated forms H 2 SeO 3 and HSeO 3 − (pKa 1 = 2.64 and pKa 2 = 8.4 [3]), and Se(VI) as a selenate oxyanion SeO 4 2− . Numerous studies have investigated the sorption of selenium oxyanions on various mineral surfaces such as iron oxyhydroxides [4][5][6][7][8][9][10][11][12][13][14], aluminium oxy-hydroxides [15][16][17][18][19][20], hydrous titanium [21] or manganese [22] oxides, copper(I) oxides [23,24], cements and clays [3,[25][26][27][28][29], soils or complex media [30][31][32][33][34][35], granite [36,37], hydroxyapatite [38], Mg/Fe carbonated layered double hydroxides [39] and iron sulphides [2,40]. In most of these sorption studies , Se(IV) appeared to be more retained by the solid surface than Se(VI).…”

Section: Introductionmentioning

confidence: 99%