Abstract: | The objectives of the present study were to quantify (1) the emission factors of a variety of dioxin emission sources; (2) the overall
dioxin emission inventory in Taiwan as well as in a major metropolitan (KC area); and (3) the contribution of power plants to the overall
PCDD/F emission. To achieve these goals, a total of 95 flue gas samples were collected and analyzed for 17 PCDD/Fs from 20 sources to
develop emission factors. The emission factor of PCDD/Fs from coal-fired power plants (0.62 lg I-TEQ ton1) obtained in this study is
considerably higher than the values reported from different countries including UK, USA, and Spain by a factor of 2–265. It means that
the air pollution control devices in certain power plants need to be more efficient. The emission data showed that there is a total annual
release to air of 6.1 and 95 g I-TEQ from major sources in the KC area and Taiwan, respectively. The dominant sources of PCDD/Fs in
the KC area are the coal-fired power plants, secondary aluminum smelting, electric arc furnaces, and open burning of rice straw, which
contributed for 56%, 17%, 13%, and 3.3% to the total, respectively. However, in Taiwan, the dominant sources of PCDD/Fs are the iron
ore sintering, coal-fired power plants, electric arc furnaces, and open burning of rice straw, which contributed for 32%, 28%, 23%, and
8.1% to the total, respectively. The results of this study showed that coal-fired power plants are very significant sources of PCDD/Fs and
also provide an important database to assist the decision makers for formulating policies to alleviate dioxin concerns. |