title: Determination of the Pb, Cr, and Cd distribution patterns with various chlorine additives in the bottom ashes of a low-temperature two-stage fluidized bed incinerator by chemical sequential extraction.
abstract: A novel low-temperature two-stage fluidized bed (LTTSFB) incinerator has been successfully developed to control heavy-metal emissions during municipal solid waste (MSW) treatment. However, the characteristics of the residual metal patterns during this process are still unclear. The aim of this study was to investigate the metal patterns in the different partitions of the LTTSFB bottom ash by chemical sequential extraction. Artificial waste was used to simulate the MSW. Different parameters including the first-stage temperature, chloride additives, and operating gas velocity were also considered. Results indicated that during the low-temperature treatment process, a high metal mobility phase exists in the first-stage sand bed. The main patterns of Cd, Pb, and Cr observed were the water-soluble, exchangeable, and residual forms, respectively. With the different Cl additives, the results showed that polyvinyl chloride addition increased metal mobility in the LTTSFB bottom ash, while, sodium chloride addition may have reduced metal mobility due to the formation of eutectic material. The second-stage sand bed was found to have a lower risk of metal leaching. The results also suggested that, the residual ashes produced by the LTTSFB system must be taken into consideration given their high metal mobility.
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC.
authors.forename: Tzu-Huan
authors.initials: TH
authors.lastname: Peng
authors.affiliation: Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan, ROC.
authors.forename: Chiou-Liang
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC. Electronic address: mywey@dragon.nchu.edu.tw.
authors.forename: Ming-Yen
authors.initials: MY
authors.lastname: Wey
mesh_terms: D005591:Chemical Fractionation; D017745:Incineration; D019216:Metals, Heavy / Q000032:analysis*; D011143:Polyvinyl Chloride; D012965:Sodium Chloride
chemical_list: D019216:Metals, Heavy; D012965:Sodium Chloride; D011143:Polyvinyl Chloride
keywords: Chemical sequential extraction; Fluidized bed; Heavy metal; Incineration; Low-temperature