[Dioxins contents in fly ash of MSW incinerator in three city]

The distribution of dioxins concentration in fly ash, which comes from three municipal wastes incinerator (MWI) in China, was studied in this paper by experimentation. It was concluded that 2, 3, 7, 8-PCDD/Fs homologue patterns of various type of fly ash were quite similar for all three MWIs. Further more, the concentrations of higher-chlorinated congeners of dioxins were remarkably higher than those of lower-chlorinated congeners. The poison effect of dioxins in the fly ash was mainly caused by PCDFs. If use active carbon powder before the equipment of bag house, the concentration of dioxins will be 1.8 times of that produced without active carbon powder. At the same time, the concentration of dioxins in flue gas will decrease accordingly.