抄録
Polychlorinated dibenzo-p-dioxins (PCDDs) in flue gases, slag and fly ashes from 7 incinerators in Kyoto Prefecture were measured as the total amounts of T4-O8CDDs by packed-column GC/MS analysis.
The results showed that various amounts of T4-O8CDDs were present in many samples and that their main component was O8CDD. Although there was no correspondence between the distributions of concentration of any congeners in different species of samples, a similarity was found in the case of the distribution of concentration of each isomer in different incinerators and samples. A tendency for the concentrations of congeners to increase was observed in proportion to the number of chlorine atoms in the ashes of the electrostatic precipitators and gases.
Estimations of the emission amounts of each congener per day and per refuse by each incinerator were also carried out. The emission amounts of each congener per day were from 1.1 to 5800mg/d. The emission ratio from each sample varied according to the incinerator and congener.
The range of emission amounts of each congener per 1 ton of refuse was from 0.013 to 64mg/t, with T4CDDs and P5CDDs being 0.013-2.1mg/t and 0.022-4.4mg/t, respectively.
Therefore, it was suggested that the formation and decomposition of PCDDs depends on the different incinerator designs and operating conditions.
