Formation pathways of polychlorinated dibenzo-p-dioxins and dibenzofurans from burning simulated PVC-coated cable wires
| Autor: | Takashi Fujimori, Kenji Shiota, Masaki Takaoka, Meng-Mei Zhang, Xiaodong Li |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Thermogravimetric analysis
Reaction mechanism Polychlorinated Dibenzodioxins Environmental Engineering Health Toxicology and Mutagenesis 0208 environmental biotechnology Inorganic chemistry chemistry.chemical_element Incineration 02 engineering and technology 010501 environmental sciences 01 natural sciences Metal Environmental Chemistry Polyvinyl Chloride Benzofurans 0105 earth and related environmental sciences Chemistry Public Health Environmental and Occupational Health General Medicine General Chemistry Dibenzofurans Polychlorinated Atmospheric temperature range Pollution Copper 020801 environmental engineering De novo synthesis Yield (chemistry) visual_art visual_art.visual_art_medium Dibenzofurans Carbon |
| Zdroj: | Chemosphere. 264:128542 |
| ISSN: | 0045-6535 |
| DOI: | 10.1016/j.chemosphere.2020.128542 |
| Popis: | Open burning of PVC-coated cables is a major source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). In the present study, the formation characteristics of PCDD/F from burning of PVC-based samples with and without metallic copper were evaluated over the dioxin formation temperature window (200–500 °C). This temperature range also inevitably occurs under open burning conditions. The PCDD/F yield from PVC added with Cu increased by factors of 1390 (300 °C), 65 (400 °C) and 17 (500 °C) compared with that from PVC alone, confirming the stimulatory effect of metallic Cu on PCDD/F production. For the first time, a relatively complete isomer-specific analysis is established for PVC acting as source of PCDD/F. Formation pathways of PCDD/F and the reaction mechanisms were investigated using a combined analysis of PCDD/F isomer signatures, thermogravimetric results and Cl K-edge X-ray absorption spectra. De novo synthesis is the major pathway leading to massive production of PCDD/F. Copper extends the temperature range for the concurrence of de(hydro)chlorination of PVC with cross-linking and aromatisation of polyenes and then stimulates cracking of the chlorine-embedded carbon network. Together, these processes contribute to the strongly enhanced formation of PCDD/F via de novo synthesis. |
| Databáze: | OpenAIRE |
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