Efficient use of Fe metal as an electron transfer agent in a heterogeneous Fenton system based on Fe0/Fe3O4 composites

Moura, Flávia C.C.; Araújo, Maria Helena; Costa, Regina C.C.; Fabris, José Domingos; Ardisson, José D.; Macedo, W. A. A.; Lago, Rochel M.

doi:10.1016/j.chemosphere.2004.12.076

Cited by 162 publications

(82 citation statements)

References 28 publications

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“…Composites with several Fe(0)/Fe 3 O 4 ratios, prepared by two different methods, i) mechanical alloying of Fe(0) and Fe 3 O 4 powders and ii) controlled (temperature-programmed) reduction of Fe 3 O 4 with H 2 , were prepared and tested in the methylene blue oxidation (MB) at different MB, iron promoter and H 2 O 2 concentrations, and pH values [124,125]. Conversion electron Mössbauer spectroscopy of a Fe(0)(50 wt%)/Fe 3 O 4 composite indicated the lack of the Fe(0) signal, suggesting that the Fe(0) particles were located in the most internal part of the mixture and covered by the particles of the oxides; high resolution transmission electron microscopy studies showed that most of the small Fe(0) particles were surrounded by the oxide phase, indicating the existence of an extensive interface between the metal and the oxide phase.…”

Section: Advanced Fenton Processes Using Modified Iron Particles and mentioning

confidence: 99%

An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials

Litter

Slodowicz

2017

Journal of Advanced Oxidation Technologies

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Abstract:The basic and applied aspects of Fenton and Fenton-like processes for removal of pollutants using zerovalent iron materials, including nanoparticles, are reviewed in this article. Only those examples including the use of the iron materials together with hydrogen peroxide addition are included. The mechanistic aspects of homogeneous and heterogeneous Fenton processes, still under discussion, are displayed. The use of biogenic generated iron nanoparticles for removal of pollutants is discussed due to their novelty and economy of synthesis.

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Section: Advanced Fenton Processes Using Modified Iron Particles and mentioning

confidence: 99%

An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials

Litter

Slodowicz

2017

Journal of Advanced Oxidation Technologies

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“…Zero valent iron has been widely used in different environmental treatment processes [16,17] and the direct electron transfer from Fe 0 to H 2 O 2 during a Fenton reaction is a very slow process at neutral pH [18]. However, Fe 0 /Fe 3 O 4 composite showed highly catalytic activity for the decomposition of H 2 O 2 as a result of an electron transfer process from metal to magnetite [18,19].…”

Section: Introductionmentioning

confidence: 99%

Degradation characteristics of humic acid over iron oxides/Fe0 core–shell nanoparticles with UVA/H2O2

Nie

Zhou

et al. 2010

Journal of Hazardous Materials

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a b s t r a c tIron oxides coated on Fe 0 core-shell nanospheres (nIOCI) were synthesized through the reduction of ferrous sulfate aqueous solution by sodium borohydride at ambient atmosphere. The catalyst was highly effective for the degradation of humic acid (HA) in the presence of H 2 O 2 and UVA at neutral pH. Under deoxygenated conditions in the dark, the generation of hydroxyl radicals in aqueous nIOCI dispersion verified its galvanic cell-like performance, which enhanced the interfacial electron transfer and led to its higher reactivity. By the total organic carbon, the absorbance of UV 254 , FTIR, the molecular weight distribution and the chemical fractional character analysis, the degradation process of HA was shown to proceed by the disappearance of aromaticity, the increase of hydrophilic fraction and aromatic ring openings into CO 2 and small organic acid. The treated HA showed much lower reactivity toward chlorine and the disinfection byproduct (DBP) formation potential was also greatly reduced. Moreover, it was found that the DBP formation potential more depended on the structure of the intermediates of HA degradation than TOC removal.Crown

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“…[12][13][14][15][16][17][18] Several metals (such as Zn, Sn, Pt) can be used as reduction agents, but iron has received the foremost emphasis due to its high efficiency in addition to its low cost and toxicity. [19][20][21][22][23][24][25][26][27][28][29] Mass spectrometry (MS) has been used for a long time for the measurement of isotopes and to determine the structure of organic molecules. Currently the major advances in mass spectrometry have occurred in the ionization sources.…”

Section: Introductionmentioning

confidence: 99%

Degradation of food dyes by zero-valent metals exposed to ultrasonic irradiation in water medium: optimization and electrospray ionization mass spectrometry monitoring

Pavanelli¹,

Bispo²,

Nascentes³

et al. 2011

J. Braz. Chem. Soc.

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A degradação redutiva de quatro corantes típicos (Azul Brilhante, Amaranto, Amarelo Crepúsculo e Vermelho 40), largamente empregados pela indústria alimentícia, por metais de valência zero (Fe e Sn), sob irradiação ultrassônica (US) em meio aquoso ácido (pH 3,0), foi estudada. As reações foram monitoradas por ESI(-)-MS (espectrometria de massas com ionização electrospray no modo negativo), além de espectrofotometria UV-Vis e carbono orgânico total (TOC). A influência de parâmetros preponderantes (tempo de exposição à radiação ultrassônica e massa do metal) nas taxas de degradação foi seguramente estabelecida por meio da construção de planejamentos fatoriais e superfícies de resposta. Deste modo, observou-se que, sob as condições experimentais otimizadas, ferro metálico (Fe) degradou eficientemente todos os corantes (com taxas de degradação superiores a 90% após 30 min de reação), enquanto que estanho metálico (Sn) apresentou um desempenho notavelmente inferior. As baixas taxas de mineralização obtidas foram consequência, provavelmente, do caráter essencialmente redutivo de tais processos. Baseado nos resultados do monitoramento por ESI(-)MS, uma rota de degradação plausível para o corante Azul Brilhante em meio aquoso, pelo sistema Fe/US, foi proposta e envolve, como etapas iniciais, a hidrogenação da ligação dupla exocíclica carbono-carbono, seguida pela inserção de hidreto no grupamento imino da molécula.The reductive degradation of four prototype dyes largely employed by the food industry (Brilliant Blue, Amaranth, Sunset Yellow and Red 40), by zero-valent metals (Fe and Sn) under ultrasonic irradiation in acidic aqueous solution (pH 3.0), was studied. The reactions were monitored by direct infusion ESI(-)-MS (electrospray ionization mass spectrometry in the negative ion mode) as well as by UV-Vis and total organic carbon (TOC). The influence of major parameters (time of exposure to ultrasonic irradiation and mass of metal) on the degradation rates was firmly established by means of factorial design and surface response approaches. Hence, it was noticed that, under the optimized experimental conditions, metallic iron (Fe) was able to efficiently degrade all the dyes (with rates higher than 90% after 30 min reaction time), whereas metallic tin (Sn) exhibited a noticeably lower performance. Low mineralization rates were achieved probably due to the essentially reductive character of such process. Based on the results from the ESI(-)-MS monitoring, a plausible degradation route for the Brilliant Blue dye in aqueous medium by the Fe/US system was proposed. Hence, this route involves, as initial pathways, the hydrogenation of the exocyclic carbon-carbon double bond of the dye followed by the insertion of hydride at its imino moiety. Keywords: electrospray ionization mass spectrometry, monitoring, food dyes, zero-valent metals IntroductionColor is by far the most important sensorial property of foods. In this way, dyes have been widely used to accentuate their original colors, or to provide different ones.While bei...

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Efficient use of Fe metal as an electron transfer agent in a heterogeneous Fenton system based on Fe0/Fe3O4 composites

Cited by 162 publications

References 28 publications

An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials

An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials

Degradation characteristics of humic acid over iron oxides/Fe0 core–shell nanoparticles with UVA/H2O2

Degradation of food dyes by zero-valent metals exposed to ultrasonic irradiation in water medium: optimization and electrospray ionization mass spectrometry monitoring

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