Desorption behaviour of polychlorinated dibenzo-p-dioxins/dibenzofurans on a packed fly ash bed

Abstract

Desorption behaviour of polychlorinated dibenzo-p-dioxins/dibenzofurans on a packed fly ash bed. Addink, R.; Govers, H.A.J.; Olie, K. Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Dechlorination/decomposition and desorption are competing processes. In this paper the desorption was studied: within PCDD/F homologues, all isomers desorb at an equal rate. Obviously, values of the activation energy of desorption from the fly ash surface (ACY~39S,d.) do not differ significantly between these isomers.

Evaluation of gas-particle partition of dioxins in flue gas I: Evaluation of gasification behavior of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ash by thermal treatment

“…Some researchers have estimated the gasification behavior of PCDD/Fs in fly ash by thermal experiments; however, the reported results are inconsistent. For example, Altwicker et al reported that, with 350 • C treatment of Ontario fly ash, 94% of PCDD/Fs were in the gaseous phase [22], whereas Addink et al reported that only 28% were detected in their gaseous form even with 398 • C treatment [23]. Such a difference in results would be understandable when the difference in thermal experimental conditions is considered and the differences in the properties of the ash samples are examined.…”

Formation of PCDD and PCDF in the thermal treatment of footwear leather wastes

“…The incinerator A consisted of a combustion chamber, a heat boiler, a cyclone and a wet scrubber. The temperature in the cyclone inlet was about 190 • C. The main contributors to the PCDD concentration were OCDD and 1,2, 3,4,6,7,8 HpCDD, both at the particulate and at the vapor phases. In case of PCDF, the trend was the same.…”

“…PCDD/Fs formation on the fly ash surface proceeds through a heterogeneous catalyzed mechanism. These reactions are catalyzed by Cu and Fe ions [3,4]. No distinction in the formation rate of PCDD/Fs was noticed between different chlorine sources (organic or inorganic) [5].…”

Dibenzodioxin Adsorption on Inorganic Materials

“…Altwicker et al 6 reported that polychlorinated dibenzodioxins/furans (PCDDs/Fs) started to evaporate from the fly ash between 300 and 350°C and about 94% PCDDs/Fs were in the gas phase. Addink et al 7 found that there was no significant desorption of PCDDs/Fs when the fly ash was treated at 150°C even after a long time (16 h); however, all isomers of PCDDs/Fs evaporated from the fly ash surface at 398°C…”

“…Thus, the adsorption/desorption behavior on many inorganic materials and adsorbents has attracted much attention. [4][5][6][7][8][9][10] Different adsorption affinities for dioxins on these materials were reported from different studies. Lasagni et al 4 have reported that about 80% of adsorbed dibenzodioxin and dibenzofuran desorbed from the silica surface at 200°C.…”