title: Stabilization of fly ash using cementing bacteria. Assessment of cementation and trace element mobilization.
abstract: Fly ash from municipal solid waste incineration (MSWI) was treated with microorganisms (Sporosarcina pasteurii and Myxococcus xanthus) to assess their capacity for cementing this waste material. Leaching tests on the samples treated with bacteria were also performed to assess the possibility of recovering and recycling trace elements from the fly ash. Sequential extractions combined with mineralogical studies demonstrated that Pb is mobile in water when associated with portlandite. Also, Cd, Pb, and Zn are primarily associated with carbonates and are mobile in acidic environments (up to 4.8, 13.9 and 248mg/l of Cd, Pb and Zn, respectively, extracted with acetic acid). Microbial treatment of the fly ash, especially with Sporosarcina pasteurii, led to its cementation and stabilization, preventing its dispersion into the environment. But samples treated with bacteria exhibited a higher capacity for trace element leaching than did untreated fly ash. The ability of these bacteria to mobilize metals can be applied to recover those of economic interest. The use of low cost biotechnologies can be an alternative to chemical treatments currently utilized for the recovery and reuse of these wastes.
authors.affiliation: Dpto. Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Prof. García González, s/n, 41012, Sevilla, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: González
authors.affiliation: Dpto. Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Prof. García González, s/n, 41012, Sevilla, Spain.
authors.forename: María Auxiliadora
authors.initials: MA
authors.lastname: Vázquez
authors.affiliation: Dpto. Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Prof. García González, s/n, 41012, Sevilla, Spain. Electronic address: aromero@us.es.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Romero-Baena
authors.affiliation: Dpto. Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Prof. García González, s/n, 41012, Sevilla, Spain.
authors.forename: Cinta
authors.initials: C
authors.lastname: Barba-Brioso
mesh_terms: D001673:Biodegradation, Environmental; D060729:Coal Ash / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis*; D006256:Hazardous Waste / Q000517:prevention & control*; D019216:Metals, Heavy / Q000032:analysis*; D016941:Myxococcus xanthus / Q000254:growth & development*; D058644:Sporosarcina / Q000254:growth & development*; D014131:Trace Elements / Q000032:analysis*
chemical_list: D060729:Coal Ash; D004785:Environmental Pollutants; D006256:Hazardous Waste; D019216:Metals, Heavy; D014131:Trace Elements
keywords: Bacteria cementation; Leaching test; Mineralogical characterization; Municipal solid waste incineration; Sequential extraction