Bioleaching of Metals Contained in Spent Catalysts by Acidithiobacillus thiooxidans DSM 26636
Spent catalysts are considered as hazardous residues of major concern, mainly due to the simultaneous presence of several metals in elevated concentrations. Although hydrometallurgical, pyrometallurgical and chelating agent methods are available to remove and recover some metals contained in spent catalysts; these procedures generate potentially hazardous wastes and the emission of harmful gases. Thus, biotechnological treatments are currently gaining importance to avoid the negative impacts of chemical technologies. To this end, diverse microorganisms have been used to assess the removal of metals from spent catalysts, comprising bacteria, archaea and fungi, whose resistance and metal uptake capabilities differ depending on the microorganism tested. Acidophilic sulfur oxidizing bacteria have been used to investigate the biotreatment and extraction of valuable metals from spent catalysts, namely Acidithiobacillus thiooxidans and Acidithiobacillus ferroxidans, as they present the ability to produce leaching agents such as sulfuric acid and sulfur oxidation intermediates. In the present work, the ability of A. thiooxidans DSM 26636 for the bioleaching of metals contained in five different spent catalysts was assessed by growing the culture in modified Starkey mineral medium (with elemental sulfur at 1%, w/v), and 1% (w/v) pulp density of each residue for up to 21 days at 30 °C and 150 rpm. Sulfur-oxidizing activity was periodically evaluated by determining sulfate concentration in the supernatants according to the NMX-k-436-1977 method. The production of sulfuric acid was assessed in the supernatants as well, by a titration procedure using NaOH 0.5 M with bromothymol blue as acid-base indicator, and by measuring pH using a digital potentiometer. On the other hand, Inductively Coupled Plasma - Optical Emission Spectrometry was used to analyze metal removal from the five different spent catalysts by A. thiooxidans DSM 26636. Results obtained show that, as could be expected, sulfuric acid production is directly related to the diminish of pH, and also to highest metal removal efficiencies. It was observed that Al and Fe are recurrently removed from refinery spent catalysts regardless of their origin and previous usage, although these removals may vary from 9.5 ± 2.2 to 439 ± 3.9 mg/kg for Al, and from 7.13 ± 0.31 to 368.4 ± 47.8 mg/kg for Fe, depending on the spent catalyst proven. Besides, bioleaching of metals like Mg, Ni, and Si was also obtained from automotive spent catalysts, which removals were of up to 66 ± 2.2, 6.2±0.07, and 100±2.4, respectively. Hence, the data presented here exhibit the potential of A. thiooxidans DSM 26636 for the simultaneous bioleaching of metals contained in spent catalysts from diverse provenance.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.2021685Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 647
 A. Kumar, B. S. Bisht, V. D. Joshi, T. Dhewa, Review on bioreme-diation of polluted environment: A management. Int. J. Env. Sci. 2011, 1 (6): 1079-1093.
 A. Ozer, H. B. Pirincci, The Adsorption of Cd (II) ions on Sulphuricacid Treated Wheat Bran. J. Haz. Mat. 2006, 13(2): 849-855.
 A. Akcil, F. Vegliò, F. Ferella, M. D. Okudan, A, A review of metal recovery from spent petroleum catalysts and ash. Waste Manage. 2015, 45: 420–433.
 Z. F. Noori, B. H. Nematdoust, G. Amoabediny, S. M. Mousavi, M. T. Amouei, An optimized integrated process for the bioleaching of a spent refinery processing catalysts. Int. J. Environ. Res. 2014, 8: 621–634
 W. Sand, T. Gehrke, P. G. Jozsa, A. Schippers, (Bio)chemistry of bacterial leaching—direct vs. indirect bioleaching. Hydrometallurgy. 2001, 59:159–175.
 K.-Y. Lee, H.-A. Kim, B.-T. Lee, S.-O. Kim, Y.-H. Kwon, K.-W Kim, A feasibility study on bioelectrokinetics for the removal of heavy metals from tailing soil. Environ Geochem Health. 2011, 33: 3–11.
 N. G. Rojas-Avelizapa, I. V. Hipólito-Juárez, M. Gómez-Ramírez, Biological treatment of coal combustion wastes by Acidithiobacillus thiooxidans DSM 26636. Mex. J. Biotechnology. 2018, 3(3): 54-67
 M. B. Medina-Arriaga. Optimización de la biolixiviación de Níquel y Vanadio en catalizadores agotados mediada por Acidithiobacillus thiooxidans (Thesis). Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada Unidad Querétaro, Instituto Politécnico Nacional, México. Junio 2016.
 N. G. Rojas-Avelizapa, M. Gómez-Ramírez, R. Hernández-Gama, J. Aburto, R. García de León, Isolation and selection of sulfur-oxidizing bacteria for the treatment of sulfur-containing hazardous wastes. Chem. Biochem. Eng. Q. 2013, 27(1): 109–117.
 S. Takakuwa, T. Nishiwaki, K. Hosoda, N. Tominaga, H. Iwasaki, Promoting effect of molybdate on the growth of a sulfur-oxidizing bacterium, Thiobagillus thiooxidans. J. Gen. Appl. Microbiol. 1977, 23: 163-173.
 NMX-K-436-1977. 1977. Determinación del ión sulfato en muestras de aguas para alimentación de calderas. Secretaria de Comercio y Fomento Industrial
 C. Cerruti, G. Curutchet, E. Donati, Bio-dissolution of spent nickel–cadmium batteries using Thiobacillus ferrooxidans. J. Biotechnol. 19986, 2: 209–219.
 M. Gomez-Ramirez, K. Zarco-Tovar, J. Aburto, R. García de León, N. G. Rojas-Avelizapa, Microbial treatment of sulfur-contaminated industrial waste. J. Environ. Sci. Health. A Tox Hazard Subst Environ Eng. 2014, 49(2): 228-232.
 A. Pathak, H. Srichandan, D.-J. Kim. Feasibility of Bioleaching in Removing Metals (Al, Ni, V and Mo) from as Received Raw Petroleum Spent Refinery Catalyst: A Comparative Study on Leaching Yields, Risk Assessment Code and Reduced Partition Index. Mater. Trans. 2015, 56(8): 1278 – 1286.
 M. Shahrabi-Farahani, S. Yaghmaei, S. M. Mousavi, F. Amiri, Bioleaching of heavy metals from a petroleum spent catalyst using Acidithiobacillus thiooxidans in a slurry bubble column bioreactor. Sep. Purif. Technol, 2014, 132: 41–49.
 P. F. Ferreira, E. F. C. Sérvulo, A. C. A. Da Costa, D. M. Ferreira, M. L. D. P. Godoy, F. J. S. Oliveira, Bioleaching of metals from a spent diesel hydrodesulfurization catalyst employing Acidithiobacillus thiooxidans FG-01. Braz. J. Chem Engineer, 2017, 34(01): 119-129.
 F. Gerayeli, F. Ghojavand, S. M. Mousavi, S. Yaghmaei, F. Amiri, Screening and optimization of effective parameters in biological extraction of heavy metals from refinery spent catalysts using a thermophilic bacterium. Sep. Purif. Technol, 2013, 118: 151-161.
 A. Pathak, M. G. Healy, L. Morrison, Changes in the fractionation profile of Al, Ni, and Mo during bioleaching of spent hydroprocessing catalysts with Acidithiobacillus ferrooxidans. J. Environ. Sci. Health. A Tox Hazard Subst Environ Eng. 2018, 0(0): 1–9.