Platinum recovery from industrial process streams by halophilic bacteria: Influence of salt species and platinum speciation.
The increased use and criticality of platinum asks for the development of effective low-cost strategies for metal recovery from process and waste streams. Although biotechnological processes can be applied for the valorization of diluted aqueous industrial streams, investigations considering real stream conditions (e.g., high salt levels, acidic pH, metal speciation) are lacking. This study investigated the recovery of platinum by a halophilic microbial community in the presence of increased salt concentrations (10-80 g L-1), different salt matrices (phosphate salts, sea salts and NH4Cl) and a refinery process stream. The halophiles were able to recover 79-99% of the Pt at 10-80 g L-1salts and at pH 2.3. Transmission electron microscopy suggested a positive correlation between intracellular Pt cluster size and elevated salt concentrations. Furthermore, the halophiles recovered 46-95% of the Pt-amine complex Pt[NH3]42+from a process stream after the addition of an alternative Pt source (K2PtCl4, 0.1-1.0 g L-1Pt). Repeated Pt-tetraamine recovery (from an industrial process stream) was obtained after concomitant addition of fresh biomass and harvesting of Pt saturated biomass. This study demonstrates how aqueous Pt streams can be transformed into Pt rich biomass, which would be an interesting feed of a precious metals refinery.
Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
Synthia
S
Maes
Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
Mathias
M
Claus
Department of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052, Zwijnaarde, Belgium.
Kim
K
Verbeken
Department of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052, Zwijnaarde, Belgium.
Elien
E
Wallaert
Department of Medical and Forensic Pathology, Ghent University, De Pintelaan 185, B-9000, Ghent, Belgium.
Rebecca
R
De Smet
Department of Analytical Chemistry, Ghent University, Krijgslaan 281 S12, B-9000, Ghent, Belgium.
Frank
F
Vanhaecke
Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
Nico
N
Boon
Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Ghent, Belgium. Electronic address: Tom.Hennebel@ugent.be.
Tom
T
Hennebel
D001419:Bacteria; D007221:Industry; D010984:Platinum; D012965:Sodium Chloride; D017673:Sodium Chloride, Dietary
D017673:Sodium Chloride, Dietary; D012965:Sodium Chloride; D010984:Platinum
Acidic saline streams; Biometallurgy; Platinum precipitation; Resource recovery; Urban mining