title: Selective recovery of nickel over iron from a nickel-iron solution using microbial sulfate reduction in a gas-lift bioreactor.
abstract: Process streams with high concentrations of metals and sulfate are characteristic for the mining and metallurgical industries. This study aims to selectively recover nickel from a nickel-iron-containing solution at pH 5.0 using a single stage bioreactor that simultaneously combines low pH sulfate reduction and metal-sulfide formation. The results show that nickel was selectively precipitated in the bioreactor at pH 5.0 and the precipitates consisted of >or=83% of the nickel content. The nickel-iron precipitates were partly crystalline and had a metal/sulfur ratio of 1, suggesting these precipitates were NiS and FeS. Experiments focusing on nickel recovery at pH 5.0 and 5.5 reached a recovery of >99.9%, resulting in a nickel effluent concentration<0.05 microM. The mixed microbial population included known sulfate reducers and acetogens. This study shows that selective metal precipitation in a single stage sulfate reducing bioreactor operated at low pH has the potential to produce metal-sulfides that can be used by the metallurgical industry as a resource for metal production.
authors.affiliation: Sub Department of Environmental Technology, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
authors.forename: Martijn F M
authors.initials: MF
authors.lastname: Bijmans
authors.forename: Pieter-Jan
authors.initials: PJ
authors.lastname: van Helvoort
authors.forename: Shabir A
authors.initials: SA
authors.lastname: Dar
authors.forename: Mark
authors.initials: M
authors.lastname: Dopson
authors.forename: Piet N L
authors.initials: PN
authors.lastname: Lens
authors.forename: Cees J N
authors.initials: CJ
authors.lastname: Buisman
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D011232:Chemical Precipitation; D003001:Cloning, Molecular; D004587:Electrophoresis, Agar Gel; D005740:Gases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis / Q000302:isolation & purification*; D009532:Nickel / Q000032:analysis / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012996:Solutions; D013431:Sulfates / Q000032:analysis / Q000378:metabolism*; D013440:Sulfides / Q000032:analysis
chemical_list: D005740:Gases; D012336:RNA, Ribosomal, 16S; D012996:Solutions; D013431:Sulfates; D013440:Sulfides; D009532:Nickel; D007501:Iron