title: Assessment of biotechnological strategies for the valorization of metal bearing wastes.
abstract: The present work deals with the application of biotechnology for the mobilization of metals from different solid wastes: end of life industrial catalysts, heavy metal contaminated marine sediments and fluorescent powders coming from a cathode ray tube glass recycling process. Performed experiments were aimed at assessing the performance of acidophilic chemoautotrophic Fe/S-oxidizing bacteria for such different solid matrices, also focusing on the effect of solid concentration and of different substrata. The achieved results have evidenced that metal solubilization seems to be strongly influenced by the metal speciation and partitioning in the solid matrix. No biological effect was observed for Ni, Zn, As, Cr mobilization from marine sediments (34%, 44%, 15%, 10% yields, respectively) due to metal partitioning. On the other hand, for spent refinery catalysts (Ni, V, Mo extractions of 83%, 90% and 40%, respectively) and fluorescent powders (Zn and Y extraction of 55% and 70%, respectively), the improvement in metal extraction observed in the presence of a microbial activity confirms the key role of Fe/S oxidizing bacteria and ferrous iron. A negative effect of solid concentration was in general observed on bioleaching performances, due to the toxicity of dissolved metals and/or to the solid organic component.
authors.affiliation: Department of Life and Environmental Sciences, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy. f.beolchini@univpm.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Beolchini
authors.forename: Viviana
authors.initials: V
authors.lastname: Fonti
authors.forename: Antonio
authors.initials: A
authors.lastname: Dell'Anno
authors.forename: Laura
authors.initials: L
authors.lastname: Rocchetti
authors.forename: Francesco
authors.initials: F
authors.lastname: Vegliò
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D002384:Catalysis; D004785:Environmental Pollutants / Q000032:analysis / Q000378:metabolism; D019015:Geologic Sediments; D007220:Industrial Waste; D007501:Iron / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism*; D009532:Nickel / Q000378:metabolism; D014639:Vanadium / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D007220:Industrial Waste; D019216:Metals, Heavy; D014639:Vanadium; D009532:Nickel; D007501:Iron