Enhanced removal of Se(VI) from water via pre-corrosion of zero-valent iron using H2O2/HCl: Effect of solution chemistry and mechanism investigation

Shan, Chao; Chen, Jiajia; Yang, Zhe; Jia, Huichao; Guan, Xiaohong; Zhang, Weiming; Pan, Bingcai

doi:10.1016/j.watres.2018.01.038

Cited by 48 publications

(14 citation statements)

References 44 publications

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“…It is important to note that the classifications of "target" and "competitor" are flexible as some of the competitor oxo-anions could also be considered "targets". For example, phosphate and geometry 83 LBH, 28,65,84 pK a , size*, 15,66,85 64,65 geometry, 83 size*, 15,66,67 65 CD, 68 geometry, 83 size*, 15,66,67 64,65,91,91 geometry, size*, 67 CD, hydration Fe−Mn oxide 3−23% LBH, 64,100 size* 67,85 pK a , CD, hydration, 70,94 , geometry Fe oxide 6% 95 Fe oxyhydroxide 1% 96 Fe−Mn (hydr) oxide 0−3% 97,98 nano-Mn oxide 30% bicarbonate HCO 3 − pK a , LBH, 64,100 geometry size*, 67,85 pK a , geometry 102,103 LBH, 20,65,104,105 size*, 67,85 LBH, 65,…”

Section: Target Oxo-anions and Competitorsmentioning

confidence: 99%

Exploring the Mechanisms of Selectivity for Environmentally Significant Oxo-Anion Removal during Water Treatment: A Review of Common Competing Oxo-Anions and Tools for Quantifying Selective Adsorption

Pincus

Rudel

Petrović

et al. 2020

Environ. Sci. Technol.

140

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Development of novel adsorbents often neglects the competitive adsorption between co-occurring oxo-anions, overestimating realistic pollutant removal potentials, and overlooking the need to improve selectivity of materials. This critical review focuses on adsorptive competition between commonly co-occurring oxo-anions in water and mechanistic approaches for the design and development of selective adsorbents. Six “target” oxo-anion pollutants (arsenate, arsenite, selenate, selenite, chromate, and perchlorate) were selected for study. Five “competing” co-occurring oxo-anions (phosphate, sulfate, bicarbonate, silicate, and nitrate) were selected due to their potential to compete with target oxo-anions for sorption sites resulting in decreased removal of the target oxo-anions. First, a comprehensive review of competition between target and competitor oxo-anions to sorb on commonly used, nonselective, metal (hydr)oxide materials is presented, and the strength of competition between each target and competitive oxo-anion pair is classified. This is followed by a critical discussion of the different equations and models used to quantify selectivity. Next, four mechanisms that have been successfully utilized in the development of selective adsorbents are reviewed: variation in surface complexation, Lewis acid/base hardness, steric hindrance, and electrostatic interactions. For each mechanism, the oxo-anions, both target and competitors, are ranked in terms of adsorptive attraction and technologies that exploit this mechanism are reviewed. Third, given the significant effort to evaluate these systems empirically, the potential to use computational quantum techniques, such as density functional theory (DFT), for modeling and prediction is explored. Finally, areas within the field of selective adsorption requiring further research are detailed with guidance on priorities for screening and defining selective adsorbents.

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Section: Target Oxo-anions and Competitorsmentioning

confidence: 99%

Exploring the Mechanisms of Selectivity for Environmentally Significant Oxo-Anion Removal during Water Treatment: A Review of Common Competing Oxo-Anions and Tools for Quantifying Selective Adsorption

Pincus

Rudel

Petrović

et al. 2020

Environ. Sci. Technol.

140

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“…Se(IV) reduction was accompanied by the generation of corrosion products that were mainly composed of magnetite and lepidocrocite (Figure ). Lepidocrocite had a good adsorption capacity to concentrate Se(VI) on the surface of ZVI particles. , The treatment of Se(IV) increased the BET surface area of nZVI from 27.0 to 73.6 m 2 /g (Figure S4), which contributed to the adsorption of Se(VI) and the subsequent Se(VI) reduction because the enrichment of Se(VI) on the nZVI surface was the prerequisite for electron transfer from Fe(0) to Se(VI) due to the heterogeneous redox reaction between Se(VI) and Fe(0). It is reported that magnetite could enhance the electron transfer from the Fe(0) core to surface-located Se(VI), , which benefited Se(VI) reduction by nZVI.…”

Section: Resultsmentioning

confidence: 99%

“…28 In addition, the pretreatments of ZVI using different oxidants were conducted to enhance Se(VI) removal. For example, Qin et al and Yoon et al employed O 2 and Fe(II) to obtain high Se(VI) removal, 29,30 where O 2 acted as an oxidant to promote the formation of iron (hydr)oxides on the ZVI surface, 31 33 Fe(II) generated from acidification could rejuvenate lepidocrocite to magnetite that has a semiconductor nature, thus facilitating the electron transfer from the Fe(0) core to Se(VI). However, O 2 and H 2 O 2 might compete with Se(VI) for electrons from ZVI, which inevitably decreased the electron efficiency.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Fe(II) could buffer the solution pH and facilitate the transformation of Fe(0) to lepidocrocite for Se(VI) adsorption on the ZVI surface . Furthermore, Shan et al used precorrosion of ZVI with H 2 O 2 /HCl to achieve efficient Se(VI) removal, in which H 2 O 2 served as an oxidant to activate the reactivity of ZVI via the oxidative attacking of the ZVI surface, and HCl could lead to the release of Fe(II) from ZVI . Fe(II) generated from acidification could rejuvenate lepidocrocite to magnetite that has a semiconductor nature, thus facilitating the electron transfer from the Fe(0) core to Se(VI).…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Removal of Selenite and Selenate by Nanosized Zerovalent Iron in Anoxic Systems: The Overlooked Role of Selenite

Miao

Zhao

Hao

et al. 2021

Environ. Sci. Technol.

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The application of nanosized zerovalent iron (nZVI) for reductive immobilization of selenite (Se(IV)) or selenate (Se(VI)) alone has been extensively investigated. However, as the predominant species, Se(IV) and Se(VI) usually coexist in the environment. Thus, it is essential to remove both species simultaneously in the solution by nZVI. Negligible Se(VI) removal (∼7%) by nZVI was observed in the absence of Se(IV). In contrast, the Se(VI) was completely removed in the presence of Se(IV), and the removal rate and electron selectivity of Se(VI) increased from 0.12 ± 0.01 to 0.29 ± 0.02 h–1 and from 1% to 4.5%, respectively, as the Se(IV) concentration increased from 0.05 to 0.20 mM. Se(IV) was rapidly removed by nZVI, and Se(VI) exerted minor influence on Se(IV) removal. Se(IV) promoted the generation of corrosion products that were mainly composed of magnetite (26%) and lepidocrocite (67%) based on the Fe K-edge XANES spectra and k 3-weighted EXAFS analysis. Fe(II) released during the Se(IV) reduction was not the main reductant for Se(VI) but accelerated the transformation of F(0) to magnetite and lepidocrocite. The formation of lepidocrocite contributed to the enrichment of Se(VI) on the nZVI surface, and magnetite promoted electron transfer from Fe(0) to Se(VI). This study demonstrated that Se(IV) acted as an oxidant to activate nZVI, thus improving the reactivity of nZVI toward Se(VI), which displays a potential application of nZVI in the remediation of Se(IV)- and Se(VI)-containing water.

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“…These compounds cover the iron surface to form a passive layer, preventing further corrosion of ZVI. 42 To date, there are various methods and techniques for improving ZVI reactivity such as acid washing, 43 H 2 -reduction pretreatment, 44 weak magnetic fields, 45 ZVI-based bimetals, 46 and nanosized ZVI (nZVI). 47 However, these techniques are always complicated, expensive and toxic to the environment.…”

Section: Introductionmentioning

confidence: 99%

Enhanced phosphate removal by zero valent iron activated through oxidants from water: batch and breakthrough experiments

Zeng

Lin

et al. 2021

RSC Adv.

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Enhanced removal of Se(VI) from water via pre-corrosion of zero-valent iron using H2O2/HCl: Effect of solution chemistry and mechanism investigation

Cited by 48 publications

References 44 publications

Exploring the Mechanisms of Selectivity for Environmentally Significant Oxo-Anion Removal during Water Treatment: A Review of Common Competing Oxo-Anions and Tools for Quantifying Selective Adsorption

Exploring the Mechanisms of Selectivity for Environmentally Significant Oxo-Anion Removal during Water Treatment: A Review of Common Competing Oxo-Anions and Tools for Quantifying Selective Adsorption

Simultaneous Removal of Selenite and Selenate by Nanosized Zerovalent Iron in Anoxic Systems: The Overlooked Role of Selenite

Enhanced phosphate removal by zero valent iron activated through oxidants from water: batch and breakthrough experiments

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