Aqueous Reductive Dechlorination of Chlorinated Ethylenes with Tetrakis(4-carboxyphenyl)porphyrin Cobalt

2005 ◽  
Vol 44 (13) ◽  
pp. 4852-4861 ◽  
Author(s):  
Joseph M. Fritsch ◽  
Kristopher McNeill
Keyword(s):  
Reductive Dechlorination ◽  
Chlorinated Ethylenes

Abiotic reductive dechlorination of chlorinated ethylenes by soil

Chemosphere ◽  
2004 ◽  
Vol 55 (5) ◽  
pp. 705-713 ◽  
Author(s):  
Woojin Lee ◽  
Bill Batchelor
Keyword(s):  
Reductive Dechlorination ◽  
Chlorinated Ethylenes

Effect of palladium on the reductive dechlorination of chlorinated ethylenes with nanoscale Pd/Fe particles

2004 ◽  
Vol 4 (5-6) ◽  
pp. 297-303
Author(s):  
H.-L. Lien ◽  
W. Zhang
Keyword(s):  
Reductive Dechlorination ◽  
Groundwater Remediation ◽  
Direct Injection ◽  
Xrd Analysis ◽  
Reaction Rates ◽  
Iron Particles ◽  
Kinetics Analysis ◽  
Excellent Performance ◽  
Chlorinated Ethylenes

Direct injection of nanoscale iron particles represents a promising technology for in-situ groundwater remediation. Nanoscale Pd/Fe particles have been shown an excellent performance for degradation of a wide array of contaminants in groundwater. The objective of this study is to investigate the nature of palladium on the reductive dechlorination of chlorinated ethylenes using nanoscale Pd/Fe particles. Kinetics analysis indicated that nanoscale Pd/Fe particles increased dechlorination rates by 1–2 orders of magnitude compared to nanoscale Fe particles alone. XRD analysis and activation energy measurement suggested that the increase of reaction rates can be attributed to the catalytic property of palladium.

Batch reactor kinetic studies on the reductive dechlorination of chlorinated ethylenes by tetrakis-(4-sulfonatophenyl)porphyrin cobalt

Chemosphere ◽  
2011 ◽  
Vol 82 (4) ◽  
pp. 592-596 ◽  
Author(s):  
Brandon R. Barnett ◽  
Alexandra L. Evans ◽  
Courtney C. Roberts ◽  
Joseph M. Fritsch
Keyword(s):  
Reductive Dechlorination ◽  
Batch Reactor ◽  
Kinetic Studies ◽  
Chlorinated Ethylenes ◽  
Reactor Kinetic

Reductive Dehalogenation of Environmental Contaminants: A Critical Review

1989 ◽  
Vol 24 (2) ◽  
pp. 299-322 ◽  
Author(s):  
R. M. Baxter
Keyword(s):  
Hydrogen Atom ◽  
Aromatic Compounds ◽  
Reductive Dechlorination ◽  
Halogen Atom ◽  
Environmental Contaminants ◽  
Methanogenic Bacteria ◽  
Photochemical Reactions ◽  
Reductive Dehalogenation ◽  
Iron Porphyrins ◽  
Aliphatic Compounds

Abstract It is generally recognized that reductive processes are more important than oxidative ones in transforming, degrading and mineralizing many environmental contaminants. One process of particular importance is reductive dehalogenation, i.e., the replacement of a halogen atom (most commonly a chlorine atom) by a hydrogen atom. A number of different mechanisms are involved in these reactions. Photochemical reactions probably play a role in some instances. Aliphatic compounds such as chloroethanes, partly aliphatic compounds such as DDT, and alicyclic compounds such as hexachlorocyclohexane are readily dechlorinated in the laboratory by reaction with reduced iron porphyrins such as hematin. Many of these are also dechlorinated by cultures of certain microorganisms, probably by the same mechanism. Such compounds, with a few exceptions, have been found to undergo reductive dechlorination in the environment. Aromatic compounds such as halobenzenes, halophenols and halobenzoic acids appear not to react with reduced iron porphyrins. Some of these however undergo reductive dechlorination both in the environment and in the laboratory. The reaction is generally associated with methanogenic bacteria. There is evidence for the existence of a number of different dechlorinating enzymes specific for different isomers. Recently it has been found that many components of polychlorinated biphenyls (PCBs), long considered to be virtually totally resistant to environmental degradation, may be reductively dechlorinated both in the laboratory and in nature. These findings suggest that many environmental contaminants may prove to be less persistent than was previously feared.

Reductive transformation of tetrachloroethylene to ethylene and ethane by an anaerobic filter

1997 ◽  
Vol 36 (6-7) ◽  
pp. 125-132 ◽  
Author(s):  
Toshiya Komatsu ◽  
Jun Shinmyo ◽  
Kiyoshi Momonoi
Keyword(s):  
Electron Donor ◽  
Laboratory Scale ◽  
Groundwater Contaminants ◽  
Reductive Transformation ◽  
Filter System ◽  
Anaerobic Filter ◽  
Anaerobic Microorganisms ◽  
Chlorinated Ethylenes ◽  
Start Up ◽  
Low Concentrations

Tetrachloroethylene (PCE) is one of the most common groundwater contaminants in Japan. PCE can be completely dechlorinated to ethylene (ETY) and ethane (ETA) by anaerobic microorganisms in the presence of a suitable electron donor. This study was conducted to examine the feasibility of using an anaerobic filter for the degradation of PCE in a bioremediation process. Laboratory-scale anaerobic filters were operated at 25°C using ethanol as the electron donor. Rapid start-up of the reactors was achieved by using anaerobic completely PCE-dechlorinating enrichment cultures as the inoculum. During the continuous operating periods, low concentrations (2.8 mg/L) of PCE were almost completely dechlorinated to ETY and ETA at hydraulic retention times of 49-15 hours with 100 mgCOD/L of ethanol. PCE concentrations as high as 80 mg/L was dechlorinated to ETY with a relatively low supply (200 mgCOD/L) of ethanol. Results of this study suggest that the anaerobic filter system is a feasible bioremediation process for the cleanup of groundwater which is contaminated by chlorinated ethylenes.

scholarly journals Reductive dechlorination in recalcitrant sources of chloroethenes in the transition zone between aquifers and aquitards

2016 ◽  
Vol 23 (18) ◽  
pp. 18724-18741 ◽  
Author(s):  
Diana Puigserver ◽  
Jofre Herrero ◽  
Mònica Torres ◽  
Amparo Cortés ◽  
Ivonne Nijenhuis ◽  
...  
Keyword(s):  
Transition Zone ◽  
Reductive Dechlorination
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