title: Bio-dissolution of Ni, V and Mo from spent petroleum catalyst using iron oxidizing bacteria.
abstract: Bioleaching studies of spent petroleum catalyst containing Ni, V and Mo were carried out using iron oxidizing bacteria. Various leaching parameters such as Fe(II) concentration, pulp density, pH, temperature and particle size were studied to evaluate their effects on the leaching efficiency as well as the kinetics of dissolution. The percentage of leaching of Ni and V were higher than Mo. The leaching process followed a diffusion controlled model and the product layer was observed to be impervious due to formation of ammonium jarosite (NH(4))Fe(3)(SO(4))(2)(OH)(6). Apart from this, the lower leaching efficiency of Mo was due to a hydrophobic coating of elemental sulfur over Mo matrix in the spent catalyst. The diffusivities of the attacking species for Ni, V and Mo were also calculated.
authors.affiliation: Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Pradhan
authors.forename: Dong J
authors.initials: DJ
authors.lastname: Kim
authors.forename: Gautam
authors.initials: G
authors.lastname: Roychaudhury
authors.forename: Seoung W
authors.initials: SW
authors.lastname: Lee
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D008982:Molybdenum / Q000378:metabolism*; D009532:Nickel / Q000378:metabolism*; D010316:Particle Size; D010578:Petroleum / Q000378:metabolism*; D012995:Solubility; D013696:Temperature; D014639:Vanadium / Q000378:metabolism*
chemical_list: D010578:Petroleum; D014639:Vanadium; D009532:Nickel; D008982:Molybdenum; D007501:Iron