Destruction of polychlorodibenzo- p -dioxins

• Published in: Nature (London) 1981-03, Vol.290 (5804), p.323-324
• Main Author: Ayres, D. C
• Format: Article
• Language: English
• Subjects: Dioxins; Humanities and Social Sciences; Kinetics; letter; multidisciplinary; Mutagens; Oxidation-Reduction; Polychlorinated Dibenzodioxins - analogs & derivatives; Science; Science (multidisciplinary); Temperature
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/290323a0

The release of 2,4,5-trichlorophenol (2,4,5-T) containing 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) at Sèveso 1 highlighted the need for an efficient control procedure for the highly toxic 2 dioxin. The concomitant formation of the dioxin and the trichlorophenol during hydrolysis of sym -tetra-chlorobenzene has lead to demands for restrictions on the use of 2,4,5-T and related herbicides 3 . An environmental hazard is also presented by pentachlorophenol 4 which includes the more highly chlorinated dioxins, in particular octachlorodibenzo- p -dioxin (OCDD). The use of pholychlorophenol formulations has been banned in Sweden on the grounds 5 that heat-stable chlorodioxins are formed during incineration; this also points to the need for degradation by chemical means. Dehalogenation of polychlorodibenzodioxins (PCDD) can be accomplished by photolysis in laboratory conditions 6 , but material adsorbed on soil is little affected 7 . Cleavage of the ether linkages with the formation of halophenols may be achieved by treatment with strong acids or quaternary ammonium salts 8 . The dibenzodioxin nucleus, is however, rather resistant to chemical attack 9 and in the absence of a suitable control procedure the use of 2,4,5-T has been restricted in the US by the Environmental Protection Agency 10,11 . I now report the oxidative degradation of TCDD and related compounds by ruthenium tetroxide.