Fate of Polychlorinated Dibenzo- p -Dioxins and Dibenzofurans in a Fly Ash Treatment Plant

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This overview attempts to outline what we currently know about the PCDD/F emission inventories and the source categories therein. Besides the best available control techniques, suggestions are offered on how to reduce the PCDD/F emission factors and emission quantity of some important PCDD/F emission sources. The PCDD/F combustion sources can be classified as either stationary or mobile or minimally/uncontrolled combustion sources. The major stationary sources of PCDD/Fs are metal production processes, waste incineration, heat and power plants, and fly ash treatment plant. Crematories, vehicles, residential boilers and stoves are of key concern due to their proximity to residential areas and their relatively lower lying stacks and exhaust gases, which may result in great impact to their surrounding environment.Moreover, we offered our perspectives on how to improve the quality and representative of the PCDD/F emission factors to attain PCDD/F inventories which correspond more to reality. These points of view include: (1) PCDD/F contributions during start-up procedures of MSWIs should be considered, (2) the sampling times of stack flue gases for EAFs and secondary metal smelters should correspond to whole smelting process stages, (3) longer flue gas sampling time should be executed for power plants, (4) direct exhaust samplings from tailpipes for mobile sources, (5) development of an open burn testing facility that can reflect the real open burning conditions, and (6) long-term sampling techniques like AMESA are suggested to used exclusively for the most contributed PCDD/F stationary sources.

Section: Pcdd/f Emissions From Eaf Dust Treatment Plantsmentioning

confidence: 99%

An Overview of PCDD/F Inventories and Emission Factors from Stationary and Mobile Sources: What We Know and What is Missing

Cheruiyot

Lee

Yan

et al. 2016

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“…Even with high PAC usage (40 kg/h), the PCDD/F concentration in flue gas still exceeds the regulatory limit of 1 ng I-TEQ/Nm 3 (factory process). This may be due to low PAC utilization efficiency (< 3%) in conventional activated carbon injection for a single bag filter system (Chi et al, 2007;Kim et al, 2007;Li et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of PCDD/Fs in a Particles Filtration Device with Activated Carbon Injection

Wang

Lin

Chang-Chien

2009

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Although numerous investigations have monitored polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions from large municipal solid waste incinerators (MSWIs) and undertaken laboratory experiments to identify the formation mechanisms of PCDD/F, the PCDD/F profiles inside an air-pollution control device have seldom been determined. This study presents the outcome of a dioxin abatement program that injected particulate activated carbon (PAC) into an MSWI. The fly ashes collected from different locations in a bag filter were examined and the mass distribution was determined. Emissions from the stack were sampled to analyze PCDD/F content after injections of 10, 13 and 17 kg/h PAC. The concentration of PCDD congeners decreased from 117.00 to 0.32 ng/Nm 3 and that of PCDF decreased from 94.84 to 0.19 ng/Nm 3 . The concentrations of filter cake ashes in different chambers and at different locations varied at 105.11-147.53 ng/g. Based on mass balance evaluation, the flow rate of PCDD/Fs in filter cake ash was 3.33 ± 0.50 ng/min; this value was roughly six times higher than that of fly ash in the disposal pit, indicating that filter cake ash treatment warrants considerable attention due to the policy for controlling PCDD/Fs.

“…Therefore, EAF fly ash is categorized as a hazardous waste. Iron ore sintering is one of the major sources of airborne emissions of PCDD/Fs in many areas (Ward et al, 2002;Kim et al, 2003;Gass et al, 2005;Li et al, 2007c). For example, sinter plants were reported to account for approximately 3.2% of total dioxin emissions in Japan, and for 19.6 and 59% in Europe and Taiwan, respectively (Lahl, 1993(Lahl, , 1994Quass et al, 2000;Kumagai et al, 2002;Wang et al, 2003a).…”

Section: Introductionmentioning

confidence: 99%

Fate of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans during the Thermal Treatment of Electric Arc Furnace Fly Ash

Lin

Zhou

Shih

et al. 2011

Thermal treatment is often employed to recover the metals contained in electric arc furnace (EAF) fly ash, which is considered a major source of PCDD/Fs. After the present treatment, the mass and volume of untreated material (EAF fly ash + cullet) were significantly reduced by 44.2 and 89.2%, respectively; meanwhile the density increased significantly by 476%. These results indicate that the mass and volume of EAF fly ash can be effectively reduced to benefit the further disposal in landfill. Additionally, this study also investigated the fate of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during the thermal treatment. For the EAF fly ash with an original PCDD