The oxidative dechlorination reaction of 2,4,6-trichlorophenol in dilute aqueous suspensions of manganese oxides

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Environmental Toxicology and Chemistry; (United States)

DOI:https://doi.org/10.1002/etc.5620121106· OSTI ID:5815109

Ukrainczyk, L; McBride, M B ^[1]

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1. Cornell Univ., Ithaca, NY (United States). Dept. of Soil, Crop and Atmospheric Sciences

Oxidation of 2,4,6-trichlorophenol (TCP) by layered manganese oxides (Na and Co-buserite) in dilute acidified aqueous suspension gives 2,6-dichloro-p-benzoquinone as a major product. This compound is likely to further polymerize and become incorporated into humus like materials. The oxidation rate was higher at lower pH and higher on Na-buserite compared to Co-buserite. TCP reacted at a faster rate than unsubstituted phenol at pH3 and 5.5, which is explained by (a) the lower half-wave potential of TCP compared to phenol; (b) a stronger bond dipole associated with the electronegative halogen, favoring an addition step in nucleophilic substitution; and (c) easier depronation of TCP at the manganese oxide-water interface due to its lower pK[sub a]. IR spectroscopy shows that TCP adsorbs in deprotonated form on the surface of manganese oxide, and it cannot be washed from the surface by water. Nucleophilic attack by addition-elimination is suggested as a mechanism of TCP dechlorination and oxidation.

• OSTI ID: 5815109
• Journal Information: Environmental Toxicology and Chemistry; (United States), Vol. 12:11; ISSN 0730-7268
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CHLORINATED AROMATIC HYDROCARBONS
DECHLORINATION
AQUEOUS SOLUTIONS
MANGANESE OXIDES
OXIDATION
PH VALUE
SUSPENSIONS
AROMATICS
CHALCOGENIDES
CHEMICAL REACTIONS
DEHALOGENATION
DISPERSIONS
HALOGENATED AROMATIC HYDROCARBONS
MANGANESE COMPOUNDS
MIXTURES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SOLUTIONS
TRANSITION ELEMENT COMPOUNDS
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)