Reductive transformation and dechlorination of chloronitrobenzenes in UASB reactor enhanced with zero-valent iron addition

Lin, Haizhuan; Zhu, Liang; Xu, Xiangyang; Zang, Lili; Kong, Yun

doi:10.1002/jctb.2520

Cited by 42 publications

(16 citation statements)

References 36 publications

(41 reference statements)

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“…The higher S 2− content in the ZVI pyr samples recycled from the systems using a higher pyrite dosage ( Fig. 4(b)) indicates increased FeS formation on the ZVI surface, through reactions shown in Eqns (5)- (7). 29 Thus, the passive (hydr)oxide film on the ZVI surface was partially replaced by FeS, which facilitates easier electron transfer from the Fe 0 core to the surfaceadsorbed oxidants (e.g.…”

Section: Resultsmentioning

confidence: 99%

“…Zero‐valent iron (ZVI) is an environmentally friendly material that is widely used for the removal of pollutants such as dyes, antibiotics, nitroaromatics, chlorinated organic compounds, and other toxic pollutants, owing to its advantages such as low cost, easy availability, and relatively strong reducibility ( E ɵ (Fe 2+ /Fe 0 ) = −0.44 V). However, ZVI remediation technology has the shortcomings of increased pH in reaction media and subsequent surface passivation due to the formation of iron (hydr)oxide film, which reduces the reactivity and reusability of the ZVI .…”

Section: Introductionmentioning

confidence: 99%

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Pyrite enhanced the reactivity of zero‐valent iron for reductive removal of dyes

Chen

Han

et al. 2020

J of Chemical Tech & Biotech

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BACKGROUND Zero‐valent iron (ZVI) is an environmentally friendly and cost‐efficient material for the removal of contaminants. However, its application is challenged by problems such as surface passivation and pH increase in the reaction media. As a potential solution for this problem, pyrite, a waste of the mining industry, was used together with ZVI for reductive removal of azo dyes. RESULTS In comparison with ZVI alone, the ZVI/pyrite mixture showed dramatically enhanced efficiency and reusability for dye removal, although pyrite itself can hardly remove dyes. The reaction rate constant kobs for the removal of Orange II at the initial pH (pH0) of 7.0 was enhanced 9.4‐ to 28.0‐fold by using the mixture at a pyrite/ZVI mass ratio ranging from 1 to 4, respectively. The mechanism studies indicate that pyrite not only helped produce more iron(II) by facilitating iron corrosion and the iron(II)/iron(III) cycle in the mixed system, but also activated the ZVI surface by in situ sulfidation. The high reactivity of the adsorbed iron(II) in the mixed system significantly contributed to dye removal, especially at the alkalescent pH. CONCLUSION Pyrite accelerated the reductive removal of dyes by ZVI, through inhibiting its surface passivation and suppressing the pH increase in the reaction media. Therefore, this research proposes a facile method for enhancing the reactivity and applicability of ZVI in environmental remediation. © 2020 Society of Chemical Industry

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pyrite enhanced the reactivity of zero‐valent iron for reductive removal of dyes

Chen

Han

et al. 2020

J of Chemical Tech & Biotech

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“…Due to starch addition the NZVI particles were stabilized by nano‐sized pools of inter‐ and intermolecular hydrogen bonding in starch molecules . The interaction between strach molecules and NZVI is very weak and hence not expected to affect the overall reactivity of NZVI . Starch addition prevented the agglomeration of NZVI particles.…”

Section: Methodsmentioning

confidence: 99%

“…The effectiveness of ZVI partly depends on its surface area to mass ratio and hence, nano‐scale zero‐valent iron (NZVI) particles are generally more effective than micron‐scale zero‐valent iron (MZVI) particles for degradation of pollutants . Zero‐valent iron interaction with chlorinated organic compounds in reductive environments generally proceeds via the reductive dechlorination process, resulting in step‐wise elimination of chlorine molecules from the chlorinated compound …”

Section: Introductionmentioning

confidence: 99%

Degradation kinetics of Endosulfan isomers by micron- and nano-sized zero valent iron particles (MZVI and NZVI)

Singh

Bose

2015

J. Chem. Technol. Biotechnol.

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BACKGROUND The pesticide Endosulfan is commercially available as a mixture of two conformal isomers, i.e. Endosulfan‐1 (Endo‐1) and Endosulfan‐2 (Endo‐2). Endosulfan has been characterized as extremely toxic by USEPA and is persistent in nature. In this study micron‐ and nano‐sized zero‐valent iron particles (MZVI and NZVI) were used for rapid degradation of the Endosulfan isomers. RESULTS Both Endo‐1 and Endo‐2 undergo abiotic hydrolysis resulting in the formation of equi‐molar quantities of Endosulfan alcohol. During interaction with MZVI, the degradation rates of both Endo‐1 and Endo‐2 were observed to be pseudo‐first‐order and the surface normalized degradation rate constants (ks) were 6.33 × 10−4 L h−1 m−2 and 6.38 × 10−4 L h−1 m−2 for Endo‐1 and Endo‐2, respectively. During interaction with NZVI, ks values for Endo‐1 and Endo‐2 were 2.58 × 10−2 L h−1m−2 and 1.21 × 10−2 L h−1 m−2, respectively. GC‐MS analysis showed evidence of the formation of partially dechlorinated by‐products due to Endo‐1 and Endo‐2 interactions with MZVI and NZVI. CONCLUSIONS Surface area normalized degradation rate constants (ks) for Endo‐1 and Endo‐2 degradation by NZVI were 40 and 19 times higher, respectively, than the corresponding values by MZVI. This indicates higher reactivity of the NZVI surface vis‐à‐vis Endo‐1 and Endo‐2 degradation. Partially dechlorinated by‐products observed during interaction of Endo‐1 and Endo‐2 with NZVI and MZVI may be less toxic and more amenable to subsequent biodegradation than the parent compounds. © 2015 Society of Chemical Industry

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“…Elemental metals are efficient reactive agents for the remediation of several classes of environmental contaminants including arsenic, azo dyes, bacteria, halogenated organic compounds, heavy metals, nitrates, nitroaromatics, radionuclides, and viruses (O´Hannesin and Gillham, 1998;Bojic et al, 2004;Bartzas et al 2006;Bojic et al, 2007;Henderson and Demond, 2007;Komnitsas et al2007;Bojic et al, 2009;Antia, 2010;Bartzas and Komnitsas, 2010;Bundschuh et al, 2010;LunaVelasco et al, 2010;Noubactep, 2010a;Phillips et al, 2010;Sarathy et al, 2010, Comba et al, 2011Giles et al, 2011;ITRC, 2011;Lin et al, 2011;Noubactep, 2011a;Salter-Blanc et al, 2011). Metallic iron (Fe 0 ) is currently the most used material for field applications (Gillham, 2010;Comba et al, 2011;Gheju, 2011;Henderson and Demond, 2011;ITRC, 2011;Salter-Blanc et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Characterising the reactivity of metallic iron in Fe<sup>0</sup>/As-rock/H<sub>2</sub>O systems by long-term column experiments

Noubactep¹

2012

WSA

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The intrinsic reactivity of 4 metallic iron materials (Fe 0 ) was investigated in batch and column experiments. The Fe 0 reactivity was characterised by the extent of aqueous fixation of in-situ leached arsenic (As). Air-homogenised batch experiments were conducted for 1 month with 10.0 g/ℓ of an As-bearing rock (ore material) and 0.0 or 5.0 g/ℓ of Fe 0 . Column experiments were performed for 2 and 3 months. Each dynamic experiment was made up of 2 glass columns in series. The first column contained 2.5 or 5.0 g of the ore material and the second column 0.0 or 5.0 g of a Fe 0 material. Results showed no significant reactivity difference in batch studies for all 4 materials; ZVI2 was by far the most reactive material in column experiments. This observation was attributed to the relative kinetics of production of aqueous As and Fe species under the experimental conditions and their impact on the formation of a protective film on Fe 0 . Accordingly, no protective film could be built at the surface of the least reactive materials. The results corroborated the urgent need for unified experimental procedures to characterise Fe 0 materials.

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Reductive transformation and dechlorination of chloronitrobenzenes in UASB reactor enhanced with zero-valent iron addition

Cited by 42 publications

References 36 publications

Pyrite enhanced the reactivity of zero‐valent iron for reductive removal of dyes

Pyrite enhanced the reactivity of zero‐valent iron for reductive removal of dyes

Degradation kinetics of Endosulfan isomers by micron- and nano-sized zero valent iron particles (MZVI and NZVI)

Characterising the reactivity of metallic iron in Fe<sup>0</sup>/As-rock/H<sub>2</sub>O systems by long-term column experiments

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