Metal catalyzed formation of chlorinated aromatic compounds: A study
of the correlation pattern in incinerator fly ash
Öberg, T., Öhrström, T., Bergström, J.
Chemosphere 67, S185-S190
(2007)
Abstract
Chlorinated aromatics are unintentionally formed and released from combustion
and other thermal processes involving organic matter and chlorine. The catalytic
activity of incinerator fly ash in the low-temperature formation of chlorinated
aromatics has been demonstrated in both laboratory experiments and full-scale
trials. Copper has been shown to be an effective catalyst, but several other
transition metals possess a similar activity. Here results are reported from a
series of full-scale combustion trials with different fractions of household and
industrial wastes, with waste from forestry as a reference fuel. The composition
of elements and chlorinated aromatics in the fly ash was evaluated with
principal component analysis and partial least squares regression. The observed
correlation pattern indicates that metals other than copper are of equal
importance for the catalytic activity. Chromium and nickel are two of these
metals, which may contribute to the de novo formation of chlorinated benzenes,
phenols, PCDD and PCDF.
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