Removal characteristics of PCDD/Fs by the dual bag filter system of a fly ash treatment plant.
In this study, a dual bag filter system was established to decrease the concentration of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in the stack flue gases of a fly ash treatment plant, which retained zinc from the fly ash of electric arc furnaces. Compared to the original single bag filter system with activated carbon injection (ACI) of 40 kg h(-1), the PCDD/F concentrations in the stack flue gas after the plant was equipped with the dual bag filter system dropped enormously from 3.38-7.73 ng I-TEQNm(-3) to 0.03 ng I-TEQNm(-3), and the total PCDD/F I-TEQ removal efficiency increased from 97.6% to 99.3% with ACI of 16 kg h(-1), that is, about 40% of the original AC usage. The AC utilization efficiency (0.560 mg I-TEQ absorbed kg ACI(-1)) of the dual bag filter system (AC: 16 kg h(-1)) was estimated about three times higher than that (0.192 mg I-TEQ absorbed kg ACI(-1)) of single bag filter system with ACI (40 kg h(-1)). The reason is that the particulate phase PCDD/Fs and some gas phase PCDD/Fs (captured by the recycled AC/ash mixture) were removed first by the first bag filter, and the rest of the gas phase PCDD/Fs were able to be adsorbed more completely by the AC/ash mixture due to a lower fly ash load, and then were removed by the second bag filter.
Lin
Wen-Yinn
WY
Institute of Environmental Engineering and Management, National Taipei University of Technology, 1 Section 3, Chung-Hsiao E. Road, Taipei 106, Taiwan, ROC.
Wang
Lin-Chi
LC
Wang
Ya-Fen
YF
Li
Hsing-Wang
HW
Chang-Chien
Guo-Ping
GP
D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control*; D001572:Benzofurans / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D005374:Filtration / Q000295:instrumentation; D052638:Particulate Matter; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry; D012037:Refuse Disposal / Q000295:instrumentation / Q000379:methods*
D000393:Air Pollutants; D001572:Benzofurans; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D052638:Particulate Matter; D000072317:Polychlorinated Dibenzodioxins; D002244:Carbon