Reductive dehalogenation of environmental contaminants: A critical review

Baxter, RM

HERO ID

2209343

Reference Type

Journal Article

Subtype

Review

Year

1989

Language

English

HERO ID 2209343
Material Type Review
In Press No
Year 1989
Title Reductive dehalogenation of environmental contaminants: A critical review
Authors Baxter, RM
Journal Water Quality Research Journal of Canada
Volume 24
Issue 2
Page Numbers 299-322
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.
Doi 10.2166/wqrj.1989.018
Wosid BCI:BCI199039083867
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English