title: Case study of polychlorinated naphthalene emissions and factors influencing emission variations in secondary aluminum production.
abstract: Secondary aluminum production has been recognized as an important source of polychlorinated naphthalenes (PCNs). Large variations in PCN emissions as the smelting process proceeds have not been determined. In this study, solid and gaseous discharges, including fly ash, slag, and stack gas samples collected from four secondary smelting plants during different smelting stages were analyzed for PCNs. The average emission factor of ∑(1-8)PCNs to air was calculated to be 17.4 mg t(-1), with a range of 4.3-29.5 mg t(-1). The average emission factors of ∑(1-8)PCNs from fly ash and slag were 55.5 ng t(-1) and 0.13 ng t(-1), respectively. The derived emission factors may enable a more accurate estimation of annual emissions and a more comprehensive knowledge of the distribution of PCNs emitted from secondary aluminum production. The emission levels and characteristics of PCNs during different smelting stages were compared. Possible factors, including the organic impurities from aluminum scrap, fuel, and chloride additives, which could contribute to variations in PCN emissions and characteristics were discussed. These results may provide useful information for developing better control strategies for reducing PCN emissions in secondary aluminum production.
authors: 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: Xiaoxu
authors: X
authors: Jiang
authors: 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. Electronic address: grliu@rcees.ac.cn.
authors: Guorui
authors: G
authors: Liu
authors: 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: Mei
authors: M
authors: Wang
authors: 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: Wenbin
authors: W
authors: Liu
authors: 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: Chen
authors: C
authors: Tang
authors: 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: Li
authors: L
authors: Li
authors: 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. Electronic address: zhengmh@rcees.ac.cn.
authors: Minghui
authors: M
authors: Zheng
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000535:Aluminum; D004784:Environmental Monitoring; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D007220:Industrial Waste; D008669:Metallurgy; D009281:Naphthalenes / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D006843:Hydrocarbons, Chlorinated; D007220:Industrial Waste; D009281:Naphthalenes; C031721:naphthalene; D000535:Aluminum
keywords: Chloride additives; Polychlorinated naphthalene; Secondary aluminum production; Smelting stages; Solid residues