Oxygen oxidizable compound, reduction

Nevertheless, an anaerobic system may be the method of choice under certain conditions (/) contamination with compounds that degrade only or better under anaerobic conditions, (2) low yield aquifers that make pump and treat methods or oxygen and nutrient distribution impractical, (J) mixed waste contamination where oxidizable compounds drive reductive dehalogenation of chlorinated compounds, or (4) deep aquifers that make oxygen and nutrient distribution mote difficult and cosdy. 

Few reactions of electrically neutral organic compounds by photoelectro-chemical means have been reported, and reduction has been observed only when oxygen has been specifically removed [91]. Reduction of a cationic organic substrate by conduction band electrons can occur, as in the case of methyl-viologens, for example [91, 92]. Chlorinated organic acids which have no oxidizable hydrogen, such as trichloroacetic acid were found to degrade, albeit in small yields [90]. This was attributed to oxidation via the valence holes which is known as a photo-KoIbe process (Scheme 33). 

In soils that become deficient in oxygen, usually as a result of flooding, the sulfide level will increase to relatively high concentrations. The formation of sulfide by sulfate reduction in nature is enhanced in warm, wet, or waterlogged soils with a pH above 6.0. Sulfide accumulation may be particularly pronounced in sulfate-rich saline areas in which plant excretions (release of carbon compounds) serve as the oxidizable carbon source, in addition to the hy-... 

Pyrrole has been functionalized with both reducible and oxidizable substituents. Examples of the first group are compounds 51-53, which have been homo- and copolymerized [254,255] poly(51) has been demonstrated to catalyze oxygen reduction. Attempts to polymerize 54 did not lead to a clean reaction [256]. Substantial amounts of dark-colored soluble products were formed. The benzoquinone 55 was successively polymerized [256] and the electrochemical behavior of the relevant polymer was studied. 

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