title: Distributions, profiles and formation mechanisms of polychlorinated naphthalenes in cement kilns co-processing municipal waste incinerator fly ash.
abstract: Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m(-3). The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g(-1). Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Guorui
authors.initials: G
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Solid Waste Reuse for Building Materials, Beijing Building Materials Academy of Sciences Research, Beijing 100041, China.
authors.forename: Jiayu
authors.initials: J
authors.lastname: Zhan
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Jianjie
authors.initials: J
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Solid Waste Reuse for Building Materials, Beijing Building Materials Academy of Sciences Research, Beijing 100041, China.
authors.forename: Chunping
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Zheng
mesh_terms: D001572:Benzofurans / Q000032:analysis; D002244:Carbon; D060729:Coal Ash; D004147:Dioxins; D004784:Environmental Monitoring; D015386:Hazardous Substances / Q000032:analysis*; D017745:Incineration; D009281:Naphthalenes / Q000032:analysis / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins; D062611:Solid Waste; D014866:Waste Products
chemical_list: D001572:Benzofurans; D060729:Coal Ash; D004147:Dioxins; D015386:Hazardous Substances; D009281:Naphthalenes; D000072317:Polychlorinated Dibenzodioxins; D062611:Solid Waste; D014866:Waste Products; D002244:Carbon; C023614:dibenzofuran; C020887:dibenzo(1,4)dioxin
keywords: Cement kiln; Fly ash; Municipal solid waste; Persistent organic pollutants; Polychlorinated naphthalenes; Stockholm Convention