Electric arc furnaces (EAFs) and industrial waste incinerators (IWIs) are major emission sources of dioxins in Taiwan. For EAFs, the flue gases were sampled after CO converter, prior to baghouse and stack to measure dioxin concentrations and to investigate the characteristics of PCDD/F congener distribution. Dioxin emissions at stages of oxidation and reduction at an EAF were also characterized. Besides, slag, BF ash, and cyclone ash were sampled and analyzed. In EAF, the PCDD/F concentration emitted at oxidation stage is higher than that during reduction stage for all sampling points, including the points of CO converter outlet, prior to baghouse and stack. The removal efficiency (86.2 %) of particulate-phase PCDD/Fs was higher than that in gas phase (35.6 %) with fabric filtration. BF ash has the highest PCDD/F concentration (31.2 ng/g) of all ashes sampled. As for IWI, WET-EP applied achieves a higher removal efficiency for particulate-phase PCDD/Fs (90.5 %) than that in gas-phase. The removal efficiency (84.5 %) of gas-phase PCDD/Fs was significantly higher than that in particulate-phase with fixed carbon bed. PCDD/F concentration of EP washing sludge is the highest (5,313 ng/g) in IWI. It is important to note that the washing water is circulated for reuse, therefore, PCDD/Fs accumulate in that, resulting in its high PCDD/F concentration. Major contributors to the dioxin concentrations at each sampling point of EAF and IWI include 1,2,3,4,6,7,8-HpCDF, OCDD and OCDF. 2,3,4,7,8-PeCDF contributes about 50 % Toxic Equivalent Quantity (TEQ) concentrations at each sampling point.

Abad, E., Caixach, J. and Rivera, J., “PCDD/F from Emission Sources and
Ambient Air in Northeast Spain”, Chemosphere, Vol. 35, pp. 453-456, 1997.
Abad, E., Adrados, M. A., Caixach, K., Fabrellas, B. and Rivera, J., “Dioxin Mass Balance in A Municipal Waste Incinerator”, Chemosphere, Vol. 40, pp. 1143-1147, 2000.
Addink, R., Bakker W. C. M. and Olie, K., “Influence of HCl and Cl2 on the Formation of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans in a Carbon/Fly Ash Mixture”, Environmental Science and Technology, 29, 2055-2058, 1995.
Alcock, R. E., Gemmill, R. and Jones, K. C., “Improvements to the UK PCDD/F and PCB Atmospheric Emission Inventory Following an Emissions Measurement Programme” Chemosphere, Vol. 38, pp 759-770, 1999.
Altwicker, E. and Millgan, M. S., "Formation of Dioxins: Competing Rates between Chemical Similar Precursors and De Novo Reaction", Chemosphere, Vol. 27, pp. 301-307, 1993.
Anderson, D. R. and Fisher, R., “Sources of Dioxins in the United Kingdom: the Steel Industry and Other Sources”, Chemosphere, Vol. 46, pp 371-381, 2002.
Babushok, V. I. and Tsang, W., “Gas-Phase Mechanism for Dioxin Formation”, Chemosphere, Vol. 51, pp 1023-1029, 2003.
Ballschmiter, K., Zoller, W., Scholtz, C. and Nottrodt, A., "Destruction of PCDD and PCDF in Bleached Pulp by Chlorine Dioxide Treatment", Chemosphere, Vol. 12, pp. 585-597, 1983.
Bonte, J. L., Fritsky, K. J., Plinke, M. A. and Wilken, M. “Catalytic Destruction of PCDD/F in a Fabric Filter: Experience at a Municipal Waste Incinerator in Belgium”, Waste Management, Vol. 22, pp 421-426, 2002.
Bueken, A. and Huang, H., “Comparative Evaluation of Techniques for Controlling the Formation and Emission of Chlorinated Dioxins/Furans in Municipal Waste Incineraiton”, Journal of Hazardous Materials, Vol. 62, pp. 1-33, 1998.
Caserini, S. and Monguzzi, A. M., “PCDD/Fs Emissions Inventory in the Lombardy Region: Results and Uncertainties” Chemosphere, Vol.48, pp. 779-786, 2002.
Chao, M. R., Hu C. W., Ma, H. W., Chang-Chien, G. P., Lee, W. J., Chang, L. W. and Wu, K. Y., “Size Distribution of Particle-Bound Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans in the Ambient Air of a Muncipal Incinerator” Atmospheric Environment, Vol.37, pp. 4945-4954, 2003.
Chen, C. M., “The Emission Inventory of PCDD/PCDF in Taiwan” Chemosphere, Vol.54, pp. 1413-1420, 2004.
Cieplik, M. K., Carbonell, J. P., Munoz, C., Baker, S., Kruger, S., Liljelind, P., Marklund, S and Louw, R., “On Dioxin Formation in Iron Ore Sintering”, Environmental Science and Technology, Vol. 37, pp. 3323-3331, 2003.
Coleman, P. J., Lee, R. G. M., Alcock, R. E. and Jones, K. C., “Observations on PAH, PCB, and PCDD/F Trends in U.K. Urban Air 1991-1995”, Environmental Science and Technology, Vol. 31, pp. 2120-2124, 1997.
Dickson, L.C., Lenoir, D. and Hutzinger, O., " Surface-Catalyzed Formation of Chlorinated Dibenzodioxins and Dibenzofurans during Incineration", Chemosphere, Vol. 19, pp. 277-282, 1989.