title: Evaluation of the emission characteristics of PCDD/Fs from electric arc furnaces.
abstract: Distribution of PCDD/F (polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran) congeners at two electric arc furnaces (EAFs) in Taiwan is evaluated via intensive stack sampling and analysis. Two kinds of exhaust system in EAFs including stack system and shutter system are selected for measuring dioxin emissions. In addition, dioxin emissions during oxidation and reduction stages at EAF-A were characterized. Results indicate that the PCDD/F concentration of stack gas in EAF-A was 4.39 ng/Nm(3) while total Toxic Equivalent Quantity (TEQ) concentration was 0.35 ng I-TEQ/Nm(3). The PCDD/F concentration of stack gas in EAF-B was 2.20 ng/Nm(3) and the TEQ concentration was 0.14 ng I-TEQ/Nm(3). 1,2,3,4,6,7,8-H(p)CDF, OCDD and OCDF are the major contributors of the dioxin concentrations for two EAFs investigated and the percentage of PCDD/F in particulate phase increases as the chlorination level of the PCDD/F congener increases. The results obtained on gas/particulate partitioning of PCDD/Fs in flue gases prior to the APCD in EAFs indicate that more than 90% exists in particulate phase. In EAF-A, the PCDD/F concentration during oxidation stage is slightly higher than that measured during reduction stage, including the sampling points of CO converter outlet, prior to bag filter and stack. Majority of PCDD/Fs emitted from steel-making processes exists in particulate-phase (about 60-70%) at both EAFs investigated.
authors.affiliation: Graduate Institute of Environmental Engineering, National Central University, Chungli 320, Taiwan. mbchang@ncuen.ncu.eu.tw
authors.forename: Moo Been
authors.initials: MB
authors.lastname: Chang
authors.forename: Hung Chi
authors.initials: HC
authors.lastname: Huang
authors.forename: Shian Sheng
authors.initials: SS
authors.lastname: Tsai
authors.forename: Kai Hsien
authors.initials: KH
authors.lastname: Chi
authors.forename: Guo Ping
authors.initials: GP
authors.lastname: Chang-Chien
mesh_terms: D000388:Air / Q000032:analysis / Q000592:standards*; D000393:Air Pollutants / Q000032:analysis*; D001572:Benzofurans / Q000032:analysis*; D000072338:Dibenzofurans, Polychlorinated; D004560:Electricity; D004784:Environmental Monitoring; D017745:Incineration / Q000295:instrumentation / Q000379:methods; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D013624:Taiwan
chemical_list: D000393:Air Pollutants; D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins