TY - JOUR
T1 - Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in oxidation of captan pesticide
AU - Chen, Kai
AU - Wojtalewicz, Dominika
AU - Altarawneh, Mohammednoor
AU - MacKie, John C.
AU - Kennedy, Eric M.
AU - Dlugogorski, Bogdan Z.
N1 - Funding Information:
This study has been funded by the Australian Research Council. KC thanks the University of Newcastle, Australia for a postgraduate research scholarship.
PY - 2011
Y1 - 2011
N2 - This study assessed the emission of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD and PCDF) from captan, a commonly used fungicide, in vapour-phase oxidative pyrolysis under conditions similar to those encountered in fires and burning biomass contaminated or treated with pesticides. The laboratory-scale apparatus consisted of a pesticide vaporiser, a tubular reactor and a product sampling system. The sampling train comprised tandem XAD-2 resin cartridges to trap PCDD/F as well as an activated charcoal tube to capture the organic volatile compounds (VOC). The analyses of PCDD/F were conducted by means of high resolution gas chromatograph (HRGC) - ion trap mass spectrometer (ITMS) and analyses of VOC by HRGC - quadrupole mass spectrometer (QMS). Substantially more PCDF formed than PCDD in the oxidative pyrolysis of captan, with higher yield of total PCDD/F observed at longer residence time. As indicated by the homologue distribution of PCDD/F, only mono to tetra chlorinated congeners were detected in our measurements, with 4-monochlorinated dibenzofuran (4-MCDF) ranking as the most abundant congener. The results of VOC analysis revealed benzene and chlorinated benzenes as important PCDD/F precursors. Combining the experimental measurements and the results of quantum chemical calculations, we established the reaction pathways for formation of PCDD/F from the vapour-phase oxidative pyrolysis of this widely employed fungicide.
AB - This study assessed the emission of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD and PCDF) from captan, a commonly used fungicide, in vapour-phase oxidative pyrolysis under conditions similar to those encountered in fires and burning biomass contaminated or treated with pesticides. The laboratory-scale apparatus consisted of a pesticide vaporiser, a tubular reactor and a product sampling system. The sampling train comprised tandem XAD-2 resin cartridges to trap PCDD/F as well as an activated charcoal tube to capture the organic volatile compounds (VOC). The analyses of PCDD/F were conducted by means of high resolution gas chromatograph (HRGC) - ion trap mass spectrometer (ITMS) and analyses of VOC by HRGC - quadrupole mass spectrometer (QMS). Substantially more PCDF formed than PCDD in the oxidative pyrolysis of captan, with higher yield of total PCDD/F observed at longer residence time. As indicated by the homologue distribution of PCDD/F, only mono to tetra chlorinated congeners were detected in our measurements, with 4-monochlorinated dibenzofuran (4-MCDF) ranking as the most abundant congener. The results of VOC analysis revealed benzene and chlorinated benzenes as important PCDD/F precursors. Combining the experimental measurements and the results of quantum chemical calculations, we established the reaction pathways for formation of PCDD/F from the vapour-phase oxidative pyrolysis of this widely employed fungicide.
KW - Dioxins
KW - Oxidative pyrolysis
KW - PCDD/F
KW - Precursors
KW - Reaction pathways
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U2 - 10.1016/j.proci.2010.07.069
DO - 10.1016/j.proci.2010.07.069
M3 - Article
AN - SCOPUS:78650875553
SN - 1540-7489
VL - 33
SP - 701
EP - 708
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 1
ER -