title: Palladium and gold removal and recovery from precious metal solutions and electronic scrap leachates by Desulfovibrio desulfuricans.
abstract: Biomass of Desulfovibrio desulfuricans was used to recover Au(III) as Au(0) from test solutions and from waste electronic scrap leachate. Au(0) was precipitated extracellularly by a different mechanism from the biodeposition of Pd(0). The presence of Cu(2+) ( approximately 2000 mg/l) in the leachate inhibited the hydrogenase-mediated removal of Pd(II) but pre-palladisation of the cells in the absence of added Cu(2+) facilitated removal of Pd(II) from the leachate and more than 95% of the Pd(II) was removed autocatalytically from a test solution supplemented with Cu(II) and Pd(II). Metal recovery was demonstrated in a gas-lift electrobioreactor with electrochemically generated hydrogen, followed by precipitation of recovered metal under gravity. A 3-stage bioseparation process for the recovery of Au(III), Pd(II) and Cu(II) is proposed.
authors.affiliation: School of Biosciences, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Creamer
authors.forename: Victoria S
authors.initials: VS
authors.lastname: Baxter-Plant
authors.forename: John
authors.initials: J
authors.lastname: Henderson
authors.forename: M
authors.initials: M
authors.lastname: Potter
authors.forename: Lynne E
authors.initials: LE
authors.lastname: Macaskie
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors; D003300:Copper / Q000302:isolation & purification; D045285:Desulfovibrio desulfuricans / Q000502:physiology*; D006046:Gold / Q000302:isolation & purification*; D007220:Industrial Waste / Q000032:analysis*; D010165:Palladium / Q000302:isolation & purification*
chemical_list: D007220:Industrial Waste; D010165:Palladium; D006046:Gold; D003300:Copper