Leachability of metals from waste incineration residues by iron- and sulfur-oxidizing bacteria. (15th February 2021)

• Record Type: Journal Article
• Authors: Kremser, Klemens; Thallner, Sophie; Strbik, Dorina; Spiess, Sabine; Kucera, Jiri; Vaculovic, Tomas; Vsiansky, Dalibor; Haberbauer, Marianne; Mandl, Martin; Guebitz, Georg M.
• Is Part Of: Journal of environmental management. Volume 280(2021)
• Publication Date: 2021-02-15
• Subjects: Waste incineration residues -- Artificial metal ore -- Bioleaching -- Metal recovery -- Iron- and sulfur-oxidizing acidophiles; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2020.111734
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Hazardous waste disposal via incineration generates a substantial amount of ashes and slags which pose an environmental risk due to their toxicity. Currently, these residues are deposited in landfills with loss of potentially recyclable raw material. In this study, the use of acidophilic bioleaching bacteria ( Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferrooxidans) as an environmentally friendly, efficient strategy for the recovery of valuable metals from incineration residues was investigated. Zinc, Cobalt, Copper, and Manganese from three different incineration residues were bio-extracted up to 100% using A. ferrooxidans under ferrous iron oxidation. The other metals showed lower leaching efficiencies based on the type of culture used. Sulfur-oxidizing cultures A. ferrooxidans and A. thiooxidans, containing sulfur as the sole substrate, expressed a significantly lower leaching efficiency (up to 50%). According to ICP-MS, ashes and slags contained Fe, Zn, Cu, Mn, Cr, Cd, and Ni in economically attractive concentrations between 0.2 and 75 mg g −1 . Compared to conventional hydrometallurgical and pyrometallurgical processes, our biological approach provides many advantages such as: the use of a limited amount of used strong acids (H2 SO4 or HCl), recycling operations at lower temperatures (~30 °C) and no emission of toxic gases during combustion (i.e., dioxins and furans). Graphical abstract: Image 1 Highlights: Bioleaching of all different residues resulting from waste incineration. Increased leachability of metals from incineration residues by iron-oxidizing bacteria. Reductive and oxidative environment facilitated microbial metal dissolution. Fe 3+ shown to be the oxidative driving force in mineral phase leaching.