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

摘要

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/Nm3 and that of PCDF decreased from 94.84 to 0.19 ng/Nm3. 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