Importance of chlorine speciation on de novo formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans
| Autor: | Abderrahmane Touati, Brian K. Gullett, Marnie Telfer, Shawn Ryan, Evalena Wikström, Dennis Tabor |
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| Rok vydání: | 2003 |
| Předmět: |
Reaction mechanism
Polychlorinated Dibenzodioxins Radical media_common.quotation_subject chemistry.chemical_element Incineration chemistry.chemical_compound polycyclic compounds Chlorine Environmental Chemistry Organic chemistry Hydrogen chloride media_common Benzofurans Air Pollutants Temperature General Chemistry Dibenzofurans Polychlorinated Refuse Disposal Waste treatment Speciation chemistry Environmental chemistry Chlorine Compounds Polychlorinated dibenzofurans Environmental Monitoring |
| Zdroj: | Environmental sciencetechnology. 37(6) |
| ISSN: | 0013-936X |
| Popis: | The role of chlorine speciation on de novo formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) has been studied thoroughly in an entrained flow reactor during simulated waste combustion. The effects of gas-phase chlorine species such as chlorine (Cl2), hydrogen chloride (HCl), and chlorine radicals (Cl*), as well as ash-bound chlorine, on PCDD/F de novo formation were isolated for investigation. The ash-bound chlorine alone was observed to be a sufficient chlorine source for PCDD/F formation. The addition of HCl to the system did not influence the yields of the PCDDs/Fs nor the degree of chlorination due to its poor chlorinating ability. Addition of 200 ppm of Cl2 to the ash-feed system resulted in increased PCDD/F yields, especially for the octa- and hepta-chlorinated congeners. Altering the reaction temperature to enable the presence of only Cl2 to the system did not change the yields of PCDD/F compared to those when both Cl2/Cl* were present. However, comparison between ash-bound and gas-phase chlorine, the latter at a concentration typical of a realistic combustion process, revealed ash-bound chlorine to be the more important chlorine source for de novo formation of PCDD/F in a full-scale incinerator. |
| Databáze: | OpenAIRE |
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