Polychlorinated dibenzo- p-dioxin (PCDD) and dibenzofurna (PCDF) isomer patterns from municipal waste combustion: Formation mechanism fingerprints

• Published in: Chemosphere (Oxford) Vol. 65; no. 9; pp. 1526 - 1536
• Main Authors: Ryu, Jae-Yong, Choi, Kum-Chan, Mulholland, James A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2006; Elsevier
• Subjects: Applied sciences; Atmospheric pollution; Chlorination; Combustion and energy production; Dechlorination; Exact sciences and technology; Gas-phase and CuCl 2-catalyzed formation; Municipal waste incinerator; Phenol condensation pathways; Pollution; Pollution sources. Measurement results; Dechlorination; Chlorination; Municipal waste incinerator; Phenol condensation pathways; Gas-phase and CuCl 2-catalyzed formation; Catalytic reaction; Dioxin derivatives; Urban waste; Pollutant formation; Organic chlorine compounds; Isomer; Persistent organic pollutant; Incineration plant; Gas-phase and Cucl2-catalyzed formation; Pollution source; Solid waste; Air pollution; Formation mechanism; Organic compounds
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2006.04.002

Polychlorinated dibenzo- p-dioxin (PCDD) and dibenzofuran (PCDF) byproducts can be formed in combustion systems by a variety of mechanisms. While total PCDD/F emissions and, to a lesser extent, homologue distributions from incinerators have been found to vary widely depending on combustion conditions, PCDD/F isomer distributions do not. Formation mechanisms can be grouped into two general categories: condensation of precursors, such as chlorinated phenols, and formation from particulate carbon, termed de novo synthesis. In addition to these mechanisms, chlorination and dechlorination reactions may affect isomer patterns. In this work, isomer patterns from field and laboratory municipal waste combustion samples are compared with computed thermodynamic distributions and those from the following experimental investigations: both gas-phase and metal-catalyzed condensation of chlorinated phenols, chlorination of dibenzo- p-dioxin and dibenzofuran, and dechlorination of octachlorodibenzo- p-dioxin and octachlorodibenzofuran. PCDD/F isomer patterns produced by different formation mechanisms in controlled experiments are distinct and robust, largely unaffected by combustion conditions. PCDD isomer patterns from municipal waste combustion are most similar to those produced by CuCl 2-catalyzed phenol condensation from 10 chlorinated phenols. PCDF isomer patterns are most similar to those produced by chlorination and dechlorination.