Effect of injection of di- and tricyclic aromatic compounds on post-combustion formation of polychlorinated dibenzo-p-dioxins and dibenzofurans
2011 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 409, no 18, 3386-3393 p.Article in journal (Refereed) Published
The formation of mono- to octachlorinated dibenzo-p-dioxins (PC(1-8)DD) and dibenzofurans (PC(1-8)DF) was studied using a model waste in a laboratory-scale combustion reactor with simultaneous collection of flue gas at three different temperatures (450°C, 300°C, and 200°C) in the post-combustion zone. To investigate the influence of chlorination reactions and the effects of carbon backbone-containing compounds present in the flue gases, five aromatic compounds were injected into the flue gas, namely dibenzofuran (DF), biphenyl (BP), naphthalene, phenanthrene and fluorene. The injection of DF induced a reduction in the concentration of PC(3-5)DD, but did not significantly influence the concentration of PCDF. A reduction in the concentration of PC(3-5)DD was also observed during the injection of fluorene, which is structurally very similar to DF. The injection of biphenyl, naphthalene and phenanthrene had less pronounced effects on the formation of PCDD and PCDF. A possible explanation of the observed changes during injection of DF and fluorene, based on homologue profiles and affected congeners, involves formation of radical species from fluorene and/or dibenzofuran. The fluorene radical is stabilized by the delocalization of electrons across the aromatic ring structure and has the propensity to react with highly abundant hydrogen chloride, whereas the molecular species would require reaction with Cl(2) or chlorine radicals.
Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2011. Vol. 409, no 18, 3386-3393 p.
PCDD/F, Waste combustion, Fluorene, Biphenyl, Naphthalene, Phenanthrene
IdentifiersURN: urn:nbn:se:umu:diva-45227DOI: 10.1016/j.scitotenv.2011.05.023ISI: 000293260100015PubMedID: 21641632OAI: oai:DiVA.org:umu-45227DiVA: diva2:427489