Dechlorination of hexachlorobenzene using lead–iron bimetallic particles

Nie, Xiaoqin; Liu, Jianguo; Yue, Dongbei; Zeng, Xianwei; Nie, Yong

doi:10.1016/j.chemosphere.2012.10.068

Cited by 31 publications

(12 citation statements)

References 31 publications

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“…Obviously, a good linear correlation was observed between ln k and 1/T, and the activation energy E a was determined to be 32.86 kJ mol −1 . This value was very close to activation energy (E a ) of the dechlorination by Pb/Fe (37.86 kJ mol −1 ) [19]. Considering the well-acknowledged fact that the activation energy for ordinary thermodynamically favored reactions is usually between 60 and 250 kJ/mol [20], the small value of activation energy for Se(IV) removal by ZVI indicated easy occurrence of the reaction and its less temperature dependency for the application in real practice.…”

Section: Effect Of Reaction Temperaturementioning

confidence: 67%

Kinetics of selenite reduction by zero-valent iron

Liang

Xiao

Yang

et al. 2013

Desalination and Water Treatment

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Zero-valent iron (ZVI) is an inexpensive agent that can remove many common environmental contaminants. The effects of dissolved oxygen (DO), pH, initial selenite concentration (Se(IV)), ZVI dosage and particle size as well as reaction temperature on Se(IV) removal by ZVI were systematically investigated in this study. Se(IV) removal by ZVI was more favored under oxic conditions with higher reaction rate than under anoxic conditions, ascribing to the promoted ZVI corrosion rate in the presence of DO. Moreover, Se(IV) removal by ZVI was enhanced with increasing ZVI dosage and reaction temperature but decreased with increasing pH and ZVI particle size. The removal rate of Se(IV) by ZVI experienced an increase and then a decrease with initial Se(IV) concentration ranging from 9.9 to 78.6 mg L −1 . To further describe the reaction rate, a pseudo-first-order kinetics was employed, and the calculated activation energy, by fitting the rate constants at different temperatures, was determined to be 32.86 kJ mol −1 . When fixing other conditions, good linear correlation could be observed between pseudo-first-order reaction rate constants (k obs ) and ZVI dosage. Compared with other methods for Se(IV) removal reported in literatures, reduction by ZVI was considered a promising technique, which could rapidly and effectively eliminate Se(IV) from waters.

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Section: Effect Of Reaction Temperaturementioning

confidence: 67%

Kinetics of selenite reduction by zero-valent iron

Liang

Xiao

Yang

et al. 2013

Desalination and Water Treatment

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“…However, the conventionally ZVI has showed a lower activity due to the precipitation of ferrous hydroxide on the surface of ZVI that blocks the reactive sites on ZVI and hinders the contact of the contaminants and ZVI, especially at neutral pH. To improve the reactivity of ZVI, a general strategy is to incorporate a second metal catalyst such as Pd, Cu, Ni, Ag, and Pt, onto ZVI to form bimetal such as palladium-catalyzed iron (Pd/Fe) [2][3][4][5], Cu/Fe [6][7][8][9], Ni/Fe [10][11][12], Pt/Fe [13], Ag/Fe [14], and Pb/Fe [15]. With the second metal catalyst added, the bimetallic system can achieve higher activity and significant improvement in the reaction kinetics for the removal of various contaminants compared with ZVI.…”

Section: Introductionmentioning

confidence: 99%

Fe/Al bimetallic particles for the fast and highly efficient removal of Cr(VI) over a wide pH range: Performance and mechanism

Cheng

Dionysiou

et al. 2015

Journal of Hazardous Materials

104

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“…This value was only about one half of the activation energy of 78–101 kJ/mol for PCB removal from contaminated dielectric oil, in which the additional energy for the dissolution KPEG in oil phase may account for the increasing activation energy21. And it is higher than the activation energy of 16.6 kJ/mol for HCB reduction with nanoscale zero-valent iron and 37.9 kJ/mol for HCB dechlorination with lead-iron bimetallic particles2627, indicating that reaction temperature had a more significant influence on the dechlorination in this study than it has in other technologies, which involve mainly heterogeneous catalytic hydrodechlorination.…”

Section: Resultsmentioning

confidence: 91%

Chemical dechlorination of hexachlorobenzene with polyethylene glycol and hydroxide: Dominant effect of temperature and ionic potential

Xiao

Jiang

Huang

2014

Sci Rep

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Persistent organic pollutants (POPs) originating from POP waste are playing an increasingly important role in the elevation of regional POP levels. In this study we realized the complete dechlorination of high concentration hexachlorobenzene (HCB) waste in the presence of polyethylene glycol and hydroxide, rather than using conventional high temperature incineration. Here, we demonstrate the dominant effect of temperature and hydroxide on HCB dechlorination in this process. Complete dechlorination of HCB was only observed at temperature about 200°C or above within 4 h reaction, and the apparent activation energy of this process was 43.1 kJ/mol. The alkalinity of hydroxides had notable effects on HCB dechlorination, and there was a considerable linear relationship between the natural logarithm of the HCB dechlorination rate constant and square root of the ionic potential of metal cation (R2 = 0.9997, p = 0.0081, n = 3). This study highlights a promising technology to realize complete dechlorination of POP waste, especially at high concentrations, in the presence of PEG in conjunction with hydroxide.

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Dechlorination of hexachlorobenzene using lead–iron bimetallic particles

Cited by 31 publications

References 31 publications

Kinetics of selenite reduction by zero-valent iron

Kinetics of selenite reduction by zero-valent iron

Fe/Al bimetallic particles for the fast and highly efficient removal of Cr(VI) over a wide pH range: Performance and mechanism

Chemical dechlorination of hexachlorobenzene with polyethylene glycol and hydroxide: Dominant effect of temperature and ionic potential

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