K. Hell et al. / Chemosphere 40 (2000) 995±1001
1001
cipal incinerator ¯y ash from reactions of chlorinated
phenols. Journal of Chromatography 389 (127), 137.
Hell, K., Stieglitz, L., Zwick, G., Will, R., 1997. Mechanistic
aspects of the de novo synthesis of PCDD/PCDF on model
¯y ash. Organohalogen Compounds 31, 492±496.
In experiments in which the phenol was evaporated
from a reservoir into the gas phase the PCDD concen-
trations are comparable to those found on Ontario ¯y
ash with 2,3,4,6-Cl4Ph as precursor, the other reaction
conditions being the same. On Ontario ¯y ash 2,4,6-
Cl3Ph was about six times less reactive than 2,3,4,6-
Cl4Ph. This result suggests that EPA ¯y ash is more
reactive than Ontario ¯y ash.
Jay, K., Stieglitz, L., 1995. Identi®cation and quali®cation of
volatile organic compounds in emissions of waste inciner-
ation plants. Chemosphere 30 (7), 1249±1260.
ꢀ
Jimenez-Leal, P., 1998. Umsetzung von Kohlenwasserstoen an
Flugaschen unter besonderer Beruck-sichtigung der Bildung
EPA ¯y ash was about three times more reactive in
the formation of PCDD from 2,4,6-Cl3Ph than our
model ¯y ash. Altogether both matrices showed similar
behavior in PCDD/F formation from 2,4,6-Cl3Ph. On
EPA ¯y ash as well as on model ¯y ash the PCDD/
PCDF ratio was ꢀ1.
von aromatischen Chlorverbindungen, Wissenschaftliche
Berichte, FZKA 6159.
Karasek, F.W., Dickson, L.C., 1992. Model studies of poly-
chlorinated dibenzo-p-dioxin formation during municipal
refuse incineration. Science 237, 754±756.
Milligan, M.S., Altwicker, E.R., 1996a. Chlorophenol reactions
on ¯y ash. I. Adorption/desorption equilibria and conver-
sion to polychlorinated dibenzo-p-dioxins. Environmental
Science and Technology 30 (1), 225±229.
Finally, it is important to note that in thermal ex-
periments with a CuCl2 doped alumina and gaseous
trichlorophenol a PCDD/PCDF ratio of about 0.7 was
observed. From that it can be concluded that far more
needs to be known about the nature of the surface in
those systems.
Milligan, M.S., Altwicker, E.R., 1996b. Chlorophenol reactions
on ¯y ash. 2. Equilibrium surface coverage and global
kinetics. Environmental Science and Technology 30 (1),
230±236.
Scholz, M., Stieglitz, L., Will, R., Zwick, G., 1997. The
formation of PCB on ¯y ash and conversion to PCDD/
PCDF. Organohalogen Compounds 31, 538±541.
Shaub, W.M., Tsang, W., 1985. Overview of dioxin formation
in gas and solid phases under municipal incinerator condi-
tions. In: Keith, L.H., Rappe, C., Choundhary, G. (Eds.),
Chlorinated Dibenzodioxins and Dibenzofurans in the
Total Environment II. Butterworths, Stoneham, MA, pp.
469±487.
Acknowledgements
Financial support by the Forschungszentrum Kar-
lsruhe for this research and the stay of K.H. at the
Rensselaer Polytechnic Institute are gratefully
acknowledged.
Stieglitz, L., Zwick, G., Beck, J., Bautz, H., Roth, W., 1989.
Carbonaceous particles in ¯y ash ± a source for the de novo
synthesis of organochlorocompounds. Chemosphere 19 (1±
6), 283±290.
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