Dechlorination of Carbon Tetrachloride by Fe(II) Associated with Goethite

Amonette, James E.; Workman, Darla J.; Kennedy, David W.; Fruchter, Jonathan S.; Gorby, Yuri A.

doi:10.1021/es9913582

Cited by 297 publications

(301 citation statements)

References 32 publications

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“…2). These results differed from the findings of other researchers who studied reactivity of sorbed Fe(II) with contaminants, where increased Fe(II) loading resulted in greater contaminant reduction rates (Klausen et al 1995;Amonette et al 2000 (Fig. 3).…”

Section: Nitrite Reactivity Experimentscontrasting

confidence: 99%

Nitrite reduction by Fe(II) associated with kaolinite

Rakshit

Matocha

Coyne

et al. 2016

Int. J. Environ. Sci. Technol.

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Interactions of iron (Fe) with the nitrogen (N) cycle have emerged and contain elements of abiotic and biological reactions. One such abiotic reaction which has received little study is the reactivity of NO 2 -and Fe(II) associated with a major clay mineral, kaolinite. The main objective of this study was to evaluate the reactivity of NO 2 -with Fe(II) added to kaolinite under anoxic conditions. Stirred batch reactivity experiments were carried out with 10 g L -1 kaolinite spiked with 25 and 100 lM Fe(II) at pH 6.45 in an anaerobic chamber. Approximately 500 lM NO 2 -was added to initiate the reaction with Fe(II)-loaded kaolinite. The rate of nitrite removal from solution was 2.4-fold slower in the high Fe(II) treatment when compared with the low Fe(II) treatment. A large portion of the NO 2 -removed from solution was confirmed to be reduced to N 2 O (g) in the Fe(II)-kaolinite slurries. However, NO 2 -reduction was also noticed in the presence of kaolinite-alone and to somewhat lesser extent in the presence of dithionite-citrate-bicarbonate (DCB)-treated kaolinite. Chemical extractions coupled with infrared spectroscopy suggest that Fe(III) oxide mineral impurities and structural Fe(III) in kaolinite may participate in NO 2 -removal from solution. Furthermore, a magnetite mineral was identified based on X-ray diffraction analysis of untreated kaolinite and DCB-treated kaolinite. Our findings reveal a novel pathway of NO 2 -transformation in the environment in the presence of Fe(II) associated (sorbed and impurity) with kaolinite.

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Section: Nitrite Reactivity Experimentscontrasting

confidence: 99%

Nitrite reduction by Fe(II) associated with kaolinite

Rakshit

Matocha

Coyne

et al. 2016

Int. J. Environ. Sci. Technol.

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“…7a and 7b) working as two-electron donor. On the other hand, as a result of surface reduction processes, physical and chemical alterations of the goethite surface occurred forming surface ferrous iron which has stronger reducing power than the pure aqueous ferrous iron (Klausen et al, 1995;Amonette et al, 2000) and is less stable than surface ferric iron (Hering and Stumm, 1990). Due to the strong reduction strength and un-stability, the surface ferrous irons could be very active sites for Cr(VI) reduction through electron transfer either intermolecular or intramolecular processes.…”

Section: Potential Reduction Pathwaysmentioning

confidence: 99%

“…It has been shown that when sulfide adsorbs onto goethite surfaces, reductive dissolution occurs in two phases: initial rapid surface reduction processes followed by slow dissolution phase (Pyzik and Sommer, 1981). Since these reduced surface and aqueous ferrous irons have very strong reduction power (Fendorf and Li, 1996;Pettine et al, 1998;Amonette et al, 2000), Cr(VI) reduction by sulfide in the presence of goethite could be affected by the produced ferrous iron. In addition, dissolved ferrous iron may react with sulfide forming ferrous sulfide at high pH values (>7) (Richard, 1974;Pyzik and Sommer, 1981;Canfield, 1989).…”

Section: Introductionmentioning

confidence: 99%

Kinetic study of hexavalent Cr(VI) reduction by hydrogen sulfide through goethite surface catalytic reaction

Kim¹,

Lan²,

Deng³

2007

Geochem. J.

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Hexavalent chromium reduction by sulfide in the presence of goethite was studied through several batch experiments. Under our specific experimental conditions including 20 µM of hexavalent chromium, 560-1117 µM of sulfide and 10.61-37.13 m 2 /L of goethite at pH of 8.45 controlled by 0.1 M borate buffer, the obtained hexavalent chromium disappearance1.5 and the determined overall rate constant (k) was 31.9 ± 4.2 (min). Among the potential major reducing agents in our comprehensive heterogeneous system such as aqueous phase sulfide, surface-associated sulfide, dissolved ferrous iron, ferrous iron on the goethite surface, as well as fresh ferrous sulfide in the solution, it was considered that the surface ferrous irons which could be produced following sulfide adsorption, played a leading role for Cr(VI) reduction as primary electron donors. In addition, no proof of the preliminary dissolution of ferrous iron from goethite to aqueous phase was observed in the experiments. Elemental sulfur was detected as the final stabilized product of sulfide and it took in charge for the promoted Cr(VI) disappearance for the successive addition of Cr(VI) at later stage.

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“…[4,14,22] However, ferrous iron from the Fe 2+ -Fe 3+ redox couple, either in aqueous solution or adsorbed on mineral surfaces, can be part of a convenient delivery path for electrons, reducing and immobilizing organic and inorganic pollutants. [23][24][25][26][27] Furthermore, pollutant coprecipitation with corrosion products has been demonstrated as another removal pathway. [28,29] Therefore there are at least three possible immobilization pathways for several pollutants: reduction by Fe°, by Fe 2+ and coprecipitation with corrosion products.…”

Section: Some Relevant Aspects Of the "Pollutant-zvi-h 2 O"-systemmentioning

confidence: 99%

Investigating the Mechanism of Uranium Removal by Zerovalent Iron

Noubactep¹,

Meinrath

Merkel

2005

Environ. Chem.

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Environmental ContextGroundwater remediation is mostly a costly long-term process. In-situ remediation by permeable reactive barriers is a potential solution. For pollution by halogenated hydrocarbons, nitrate, and chromium, zerovalent iron (ZVI) has been found to induce a chemical reduction.ZVI remediation technology has been extended to metal pollution, where one of the major removal mechanisms seems to be co-precipitation with the products of iron corrosion. Due to difficulties of identifying reaction products in the matrix of corrosion products, investigation methods for characterising the contaminant removal with respect to interactions between contaminant and corrosion products need to be developed. AbstractZerovalent iron (ZVI) has been proposed as a reactive material in permeable in-situ walls for groundwater contaminated by metal pollutants. For such pollutants which interact with corrosion products, the determination of the actual mechanism of their removal is very important to predict the long-term stability of reactive walls. From a study of the effects of pyrite (FeS 2 ) and manganese nodules (MnO 2 ) on the uranium removal potential of a selected ZVI material, a test methodology (FeS 2 -MnO 2 -method) is suggested to follow the pathway of contaminant removal by ZVI materials. An interpretation of the removal potential of ZVI for uranium in presence of both additives corroborates coprecipitation with iron corrosion products as a major removal mechanism for uranium.

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Dechlorination of Carbon Tetrachloride by Fe(II) Associated with Goethite

Cited by 297 publications

References 32 publications

Nitrite reduction by Fe(II) associated with kaolinite

Nitrite reduction by Fe(II) associated with kaolinite

Kinetic study of hexavalent Cr(VI) reduction by hydrogen sulfide through goethite surface catalytic reaction

Investigating the Mechanism of Uranium Removal by Zerovalent Iron

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