title: A full-scale study on thermal degradation of polychlorinated dibenzo- p-dioxins and dibenzofurans in municipal solid waste incinerator fly ash and its secondary air pollution control in China.
abstract: Degradation of polychlorinated dibenzo- p-dioxins and dibenzofurans in municipal solid waste incinerator fly ash is beneficial to its risk control. Fly ash was treated in a full-scale thermal degradation system (capacity 1 t d-1) to remove polychlorinated dibenzo- p-dioxins and dibenzofurans. Apart from the confirmation of the polychlorinated dibenzo- p-dioxin and dibenzofuran decomposition efficiency, we focused on two major issues that are the major obstacles for commercialising this decomposition technology in China, desorption and regeneration of dioxins and control of secondary air pollution. The toxic equivalent quantity values of polychlorinated dibenzo- p-dioxins and dibenzofurans decreased to <6 ng kg-1and the detoxification rate was ⩾97% after treatment for 1 h at 400 °C under oxygen-deficient conditions. About 8.49% of the polychlorinated dibenzo- p-dioxins and dibenzofurans in toxic equivalent quantity (TEQ) of the original fly ash were desorbed or regenerated. The extreme high polychlorinated dibenzo- p-dioxin and dibenzofuran levels and dibenzo- p-dioxin and dibenzofuran congener profiles in the dust of the flue gas showed that desorption was the main reason, rather than de novo synthesis of polychlorinated dibenzo- p-dioxins and dibenzofurans in the exhaust pipe. Degradation furnace flue gas was introduced to the municipal solid waste incinerator economiser, and then co-processed in the air pollution control system. The degradation furnace released relatively large amounts of cadmium, lead and polychlorinated dibenzo- p-dioxins and dibenzofurans compared with the municipal solid waste incinerator, but the amounts emitted to the atmosphere did not exceed the Chinese national emission limits. Thermal degradation can therefore be used as a polychlorinated dibenzo- p-dioxin and dibenzofuran abatement method for municipal solid waste incinerator source in China.
authors.affiliation: 1 State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
authors.forename: Xingbao
authors.initials: X
authors.lastname: Gao
authors.affiliation: 1 State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.|2 School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, China.
authors.forename: Bingjing
authors.initials: B
authors.lastname: Ji
authors.affiliation: 1 State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
authors.forename: Dahai
authors.initials: D
authors.lastname: Yan
authors.affiliation: 1 State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
authors.forename: Qifei
authors.initials: Q
authors.lastname: Huang
authors.affiliation: 1 State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Zhu
mesh_terms: D000393:Air Pollutants / Q000737:chemistry; D000397:Air Pollution / Q000032:analysis / Q000517:prevention & control*; D002681:China; D060729:Coal Ash / Q000032:analysis* / Q000737:chemistry; D000072338:Dibenzofurans, Polychlorinated / Q000737:chemistry*; D017745:Incineration / Q000295:instrumentation / Q000379:methods*; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry*; D012037:Refuse Disposal / Q000295:instrumentation / Q000379:methods; D062611:Solid Waste
chemical_list: D000393:Air Pollutants; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins; D062611:Solid Waste
keywords: Municipal solid waste incinerator fly ash; congener profiles; detoxification rate; polychlorinated dibenzo-p-dioxins and dibenzofurans; secondary pollution control; thermal degradation