The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron

Hou, Meifang; Li, Fangbai; Liu, Xinming; Wang, Xugang; Wan, Hongfu

doi:10.1016/j.jhazmat.2006.11.019

Cited by 101 publications

(62 citation statements)

References 24 publications

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“…The discussion above unequivocally show that the experimental conditions of Hou et al [1] should have been more optimally selected. This weakness is partly due to the failure of pioneers works of the iron technology to properly consider the available literature on: (i) iron corrosion, and (ii) the use of elemental iron in the synthetic organic chemistry.…”

Section: Discussionmentioning

confidence: 93%

“…Nevertheless, the authors may have pay more attention to the work of Mielczarski et al [12] who discussed in some details the role of oxide-film on the removal of azo dyes by Fe 0 in weak acidic solutions. Clearly a different choice in experimental conditions may have increased the value of the interesting work of Hou et al [1]. …”

Section: Discussionmentioning

confidence: 99%

“…The study of Hou et al [ 1] is very informative to researchers interested in the field of iron technology. However, the article contains areas where improvements could be made that will be discussed below.…”

mentioning

confidence: 99%

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Comments on “The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron” by M. Hou, et al. [J. Hazard. Mater. 145 (2007) 305]

Noubactep

2007

Journal of Hazardous Materials

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Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Comments on “The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron” by M. Hou, et al. [J. Hazard. Mater. 145 (2007) 305]

Noubactep

2007

Journal of Hazardous Materials

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“…Decomposition of PCE and PCP treated with zerovalent iron only Zero-valent iron (ZVI or Fe 0 ) serves as an electron donor (reducing agent) to reduce organic substances (Hou et al, 2007); the rate can be approximated by a first-order reaction (Lin et al, 2004;Janda et al, 2004;Lien and Zhang, 2005):…”

Section: Resultsmentioning

confidence: 99%

Microwave-induced nanoscale zero-valent iron degradation of perchloroethylene and pentachlorophenol

Lee¹,

Lin

Jou

2012

Journal of the Air & Waste Management Association

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Microwave (MW) is applied to enhance perchloroethylene (PCE) or pentachlorophenol (PCP) removal using zero-valent iron (ZVI; Fe 0 ) as the dielectric medium. ZVI has a much higher dielectric loss factor (39.5) than other media; it is capable of absorbing MW radiation rapidly to speed up the release of electrons, leading to rises of the ZVI particle surface temperature. If the MW power is continued, excessive electricity will accumulated inside ZVI particles, resulting in sparks. The results show that during the initial 5 sec (700 W), the linear aliphatic PCE has a faster decomposing rate than the ringed PCP (82.0% vs. 4.8%) because less energy is required for decomposing the linear-chlorine bond (90 kcal mol À1 ) than ring-chlorine bonds (95 kcal mol À1 ). Later, the removal rate for either PCE or PCP remains the same when the exposure time is between 5 and 60 sec. Without MW irradiation, linear PCE molecules have larger surface area to contact ZVI, and hence they have better removal efficiencies than PCP molecules. Using Fe 0 as a microwave dielectric medium to treat PCE or PCP is a new and worthwhile treatment technology; it is environmentally friendly, and its use will eliminate the secondary pollution.Implications: Nanoscale iron particles are characterized by high surface-area-to-volume ratios, high specific surface area, and high surface reactivity. With a much higher dielectric loss factor, it is capable of absorbing MW radiation rapidly to speed up the release of electrons, leading to rise in temperature. The time needed to achieve a satisfactory treatment is also reduced, leading to significant saving of energy consumption to make this method cost-effective and also environmentally friendly for the industry to pursuit sustainable development.

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“…The use of metallic iron in environmental remediation, indeed, dates back to the midseventies, when it was used as filling reactive material in the Permeable Reactive Barrier technology for reductive dechlorination of halogenated hydrocarbons [39,40]. This ability has prompted the use of iron particles, ranging from millimetric to nanometric scale, for degradation of other contaminants [41], including pesticides [42,43], nitroaromatics [44], metal ions [31,36,39,45], and dyes [30,[46][47][48][49][50][51][52].…”

Section: Introductionmentioning

confidence: 99%

Role of pH in the Aqueous Phase Reactivity of Zerovalent Iron Nanoparticles with Acid Orange 7, a Model Molecule of Azo Dyes

Freyria

Esposito

Armandi

et al. 2017

Journal of Nanomaterials

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The effect of both pH and surface oxidation of nanoparticles is studied on the interaction between a commercial slurry of Nanoscale Zerovalent Iron (NZVI) and the azo dye Acid Orange 7 (AO7). NZVI is a reducing agent used for the degradation of several pollutants, including azo dyes: during pollutant degradation, it undergoes progressive oxidation and dissolution. Though it is generally acknowledged that NZVI consists of core-shell nanoparticles, where the core of metallic iron is covered by Fe O shell, it still remains a poorly defined system. In this work, the solid fraction recovered by filtration and drying was characterized by means of XRD diffraction with Rietveld refinement, N 2 isotherms at 77 K, FE-SEM and TEM observation, EDX analysis, and IR spectroscopy. Powders were obtained from both the parent slurry and the same slurry pretreated with HCl in order to remove Fe O shell, finally reactivating the nanoparticles. The aforementioned physicochemical characterization allowed figuring out some correlations between the properties of the studied nanomaterial and the processes occurring when it is in contact with AO7 in aqueous phase. The type of interaction occurring within the NZVI/AO7 system (adsorption and type of redox reactions) strongly depends not only on the pH of the starting solution, but also on the surface oxidation of the nanoparticles.

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The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron

Cited by 101 publications

References 24 publications

Comments on “The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron” by M. Hou, et al. [J. Hazard. Mater. 145 (2007) 305]

Comments on “The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron” by M. Hou, et al. [J. Hazard. Mater. 145 (2007) 305]

Microwave-induced nanoscale zero-valent iron degradation of perchloroethylene and pentachlorophenol

Role of pH in the Aqueous Phase Reactivity of Zerovalent Iron Nanoparticles with Acid Orange 7, a Model Molecule of Azo Dyes

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