Decolorization of organic dyes by zero-valent iron in the presence of oxalic acid and influence of photoirradiation and hexavalent chromium

Wei, Shouqiang; Ren, Hongju; Li, Jinqiu; Shi, Jing; Shao, Zhongcai

doi:10.1016/j.molcata.2013.09.002

Cited by 14 publications

(5 citation statements)

References 52 publications

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“…Similar to the Fenton reaction in the presence of H 2 O 2 , Fe(II/III)-oxalate system also reported having the superior capacity to degrade organic pollutants ( Wei et al, 2013 , Liu et al, 2012 , Lan et al, 2008 ). A FeWO 4 nanosheet material synthesised by a hydrothermal method showed facet dependent surface Fenton chemistry in the presence of oxalic acid ( Li et al, 2019 ).…”

Section: Various Fe-based Materials Related To the Fenton Processmentioning

confidence: 80%

Heterogeneous Fenton catalysts: A review of recent advances

Thomas

Dionysiou

Pillai

2021

Journal of Hazardous Materials

503

162

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Heterogeneous Fenton catalysts are emerging as excellent systems for applications related to water purification. In this review, recent trends in the synthesis and application of heterogeneous Fenton catalysts for the abatement of organic pollutants and disinfection of microorganisms are discussed. It is noted that as the complexity of cell wall increases, the resistance level towards various disinfectants increases and it requires either harsh conditions or longer exposure time for the complete disinfection. In case of viruses, enveloped viruses ( e.g. SARS-CoV-2) are found to be more susceptible to disinfectants than the non-enveloped viruses. The introduction of plasmonic systems with the Fenton catalysts broaden the visible light absorption efficiency of the hybrid material, and incorporation of semiconductor material improves the rate of regeneration of Fe(II) from Fe(III). A special emphasis is given to the use of Fenton catalysts for antibacterial applications. Composite materials of magnetite and ferrites remain a champion in this area because of their easy separation and reuse, owing to their magnetic properties. Iron minerals supported on clay materials, perovskites, carbon materials, zeolites and metal-organic frameworks (MOFs) dramatically increase the catalytic degradation rate of contaminants by providing high surface area, good mechanical stability, and improved electron transfer. Moreover, insights to the zero-valent iron and its capacity to remove a wide range of organic pollutants, heavy metals and bacterial contamination are also discussed. Real world applications and the role of natural organic matter are summarised. Parameter optimisation (e.g. light source, dosage of catalyst, concentration of H 2 O 2 etc. ), sustainable models for the reusability or recyclability of the catalyst and the theoretical understanding and mechanistic aspects of the photo-Fenton process are also explained. Additionally, this review summarises the opportunities and future directions of research in the heterogeneous Fenton catalysis.

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Section: Various Fe-based Materials Related To the Fenton Processmentioning

confidence: 80%

Heterogeneous Fenton catalysts: A review of recent advances

Thomas

Dionysiou

Pillai

2021

Journal of Hazardous Materials

503

162

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“…Hexavalent chromium [Cr(VI)], a well-known harmful heavy metal pollutant to human health, is often produced from industrial production or oxidation of trivalent chromium [Cr(III)] in nature. − The most common strategy for treatment of Cr(VI)-containing pollution is to reduce Cr(VI) into less toxic and easily fixed Cr(III) by reductants, e.g., S 2– , SO 3 2– , Fe(II), and FeS 2 , − followed by adjusting the pH value to precipitate Cr(III) from solution in the form of Cr(III) hydroxide [Cr(OH) 3 ] or Cr(III)–Fe(III) hydroxides [Cr x Fe 1– x (OH) 3 ]. , In general, Cr(OH) 3 has poor stability due to the loose octahedral coordination structure in the first nearest neighboring (Cr–O) shell . Comparatively, Cr(III)–Fe(III) hydroxides present a higher stability, owing to the close arrangement of Cr–O coordination surrounded by the Fe–O octahedral structure, and thus, it is considered as the stable form of Cr(III) in rCOPR. , …”

Section: Introductionmentioning

confidence: 99%

Visible Light Accelerates Cr(III) Release and Oxidation in Cr–Fe Chromite Residues: An Overlooked Risk of Cr(VI) Reoccurrence

Lei

Gou

Wang

et al. 2022

Environ. Sci. Technol.

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The reduced chromite ore processing residue (rCOPR) deposited in environments is susceptible to surrounding factors and causes reoccurrence of Cr(VI). However, the impact of natural sunlight on the stability of rCOPR is still unexplored. Herein, we investigated the dissolution and transformation behaviors of Cr(III)−Fe(III) hydroxide, a typical Cr(III)-containing component in rCOPR, under visible light. At acidic conditions, the release rate of Cr(III) under illumination markedly increased, up to 7 times higher than that in the dark, yet no Cr(VI) was produced. While at basic conditions, only Cr(VI) was obtained by photooxidation, with an oxidation rate of ∼7 times higher than that by δ-MnO 2 under dark conditions at pH 10, but no reactive oxygen species was generated. X-ray absorption near-edge structure and density functional theory analyses reveal that coexisting Fe in the solid plays a critical role in the pH-dependent release and transformation of Cr(III), where photogenerated Fe(II) accelerates Cr(III) produced at acidic conditions. Meanwhile, at basic conditions, the production of intermediate Cr(III)−Fe(III) clusters by light leads to the oxidation of Cr(III) into Cr(VI) through the nonradical "metal-to-metal charge transfer" mechanism. Our study provides a new insight into Cr(VI) reoccurrence in rCOPR and helps in predicting its environmental risk in nature.

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“…Mazellier and Sulzberger reported an α-FeOOH/oxalate system and systematically explored the mechanism of Fe(II) formation and the role of oxalate. Wei et al studied a zero-valent iron (Fe 0 )/oxalate system for the simultaneous and rapid redox removal of chromium (Cr(VI)) and orange II and its relative mechanism. Recent studies of Fe/oxalate systems have focused on designing composite structures, different Fe-based compounds, and so forth to improve the stability and activity of the system. − Zhang et al reported the hematite with exposed different facets for U(VI) removal.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Generation of Reactive Oxygen Species under Visible Light Irradiation by Adjusting the Exposed Facet of FeWO₄ Nanosheets To Activate Oxalic Acid for Organic Pollutant Removal and Cr(VI) Reduction

Xiao

Wang

et al. 2019

Environ. Sci. Technol.

177

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In this work, taking FeWO 4 nanosheets as an example, the activation of oxalic acid (OA) based on facet engineering for the enhanced generation of active radical species was reported, revealing unprecedented surface Fenton activity for pollutant degradation. Density functional theory calculations confirmed the more efficient generation of reactive oxygen species over FeWO 4 nanosheets with the {001} facet exposed (FWO-001) under visible light irradiation compared to the efficiency of FeWO 4 nanosheets with the {010} facet exposed (FWO-010), which could be attributed to a higher density of iron and the efficient activation of OA on the {001} facet. The H 2 O 2 -derived • OH tended to diffuse away from the active sites of FWO-001 into solution to favor the continuous activation of OA into the active radicals for pollutant redox reactions, but preferred to remain on FWO-010 to hinder the further activation of OA on the {010} facet. Additionally, the generation of • CO 2 − endowed FeWO 4 with a strong reduction ability. Compared with FWO-010, FWO-001 exhibited enhanced redox activity for the catalytic degradation of organic pollutants and Cr(VI) in the optimized conditions. These findings can help in understanding the facet dependent surface Fenton chemistry of catalytic redox reactions and in designing efficient catalysts for environmental decontamination.

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Decolorization of organic dyes by zero-valent iron in the presence of oxalic acid and influence of photoirradiation and hexavalent chromium

Cited by 14 publications

References 52 publications

Heterogeneous Fenton catalysts: A review of recent advances

Heterogeneous Fenton catalysts: A review of recent advances

Visible Light Accelerates Cr(III) Release and Oxidation in Cr–Fe Chromite Residues: An Overlooked Risk of Cr(VI) Reoccurrence

Enhanced Generation of Reactive Oxygen Species under Visible Light Irradiation by Adjusting the Exposed Facet of FeWO₄ Nanosheets To Activate Oxalic Acid for Organic Pollutant Removal and Cr(VI) Reduction

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Decolorization of organic dyes by zero-valent iron in the presence of oxalic acid and influence of photoirradiation and hexavalent chromium

Cited by 14 publications

References 52 publications

Heterogeneous Fenton catalysts: A review of recent advances

Heterogeneous Fenton catalysts: A review of recent advances

Visible Light Accelerates Cr(III) Release and Oxidation in Cr–Fe Chromite Residues: An Overlooked Risk of Cr(VI) Reoccurrence

Enhanced Generation of Reactive Oxygen Species under Visible Light Irradiation by Adjusting the Exposed Facet of FeWO4 Nanosheets To Activate Oxalic Acid for Organic Pollutant Removal and Cr(VI) Reduction

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Enhanced Generation of Reactive Oxygen Species under Visible Light Irradiation by Adjusting the Exposed Facet of FeWO₄ Nanosheets To Activate Oxalic Acid for Organic Pollutant Removal and Cr(VI) Reduction