title: Behavior of cesium in municipal solid waste incineration.
abstract: As a result of the Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 in Japan radioactive nuclides, primarily (134)Cs and (137)Cs were released, contaminating municipal solid waste and sewage sludge in the area. Although stabilizing the waste and reducing its volume is an important issue differing from Chernobyl nuclear power plant accident, secondary emission of radioactive nuclides as a result of any intermediate remediation process is of concern. Unfortunately, there is little research on the behavior of radioactive nuclides during waste treatment. This study focuses on waste incineration in an effort to clarify the behavior of radioactive nuclides, specifically, refuse-derived fuel (RDF) with added (133)Cs (stable nuclide) or (134)Cs (radioactive nuclide) was incinerated in laboratory- and pilot-scale experiments. Next, thermogravimetric (TG) and differential thermal analysis (DTA) of stable Cs compounds, as well as an X-ray absorption fine structure (XAFS) analysis of Cs concentrated in the ashes were performed to validate the behavior and chemical forms of Cs during the combustion. Our results showed that at higher temperatures and at larger equivalence ratios, (133)Cs was distributed to the bottom ash at lower concentration, and the influence of the equivalence ratio was more significant at lower temperatures. (134)Cs behaved in a similar fashion as (133)Cs. We found through TG-DTA and XAFS analysis that a portion of Cs in RDF vaporizes and is transferred to fly ash where it exists as CsCl in the MSW incinerator. We conclude that Cs-contaminated municipal solid wastes could be incinerated at high temperatures resulting in a small amount of fly ash with a high concentration of radioactive Cs, and a bottom ash with low concentrations.
authors.affiliation: Graduate School of Global Environmental Studies, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan; Department of Chemical Engineering, KU Leuven, Jan De Nayerlaan 5, 2860 Sint-Katelijne-Waver, Belgium. Electronic address: oshita@epsehost.env.kyoto-u.ac.jp.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Oshita
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Aoki
authors.affiliation: Research Reactor Institute, Kyoto University, Kumatori, Sennangun, Osaka 590-0494, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fukutani
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Shiota
authors.affiliation: Graduate School of Global Environmental Studies, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujimori
authors.affiliation: Graduate School of Global Environmental Studies, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takaoka
mesh_terms: D056804:Biofuels / Q000032:analysis*; D002586:Cesium / Q000032:analysis*; D002588:Cesium Radioisotopes / Q000032:analysis*; D060729:Coal Ash / Q000032:analysis*; D004055:Differential Thermal Analysis; D017745:Incineration; D062611:Solid Waste / Q000032:analysis*; D013818:Thermogravimetry
chemical_list: D056804:Biofuels; D002588:Cesium Radioisotopes; D060729:Coal Ash; D062611:Solid Waste; D002586:Cesium
keywords: Cesium; Equivalence ratio; Incineration; Municipal solid waste; Radioactive nuclides