Palladium and gold removal and recovery from... : Biotechnology Letters (original) (raw)

Palladium and gold removal and recovery from precious metal solutions and electronic scrap leachates by Desulfovibrio desulfuricans

Neil J. Creamer
Victoria S. Baxter-Plant
John Henderson
M. Potter
Lynne E. Macaskie

Biotechnology Letters

(

)

1475

1484

September 2006

| DOI: 10.1007/s10529-006-9120-9

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 Cu2+ (˜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 Cu2+ 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.