Bioelectrochemical recovery of Cu, Pb, Cd, and Zn from dilute solutions.
In a microbial bioelectrochemical system (BES) living microorganisms catalyze the anodic oxidation of organic matter at a low anode potential. We used a BES with a biological anode to power the cathodic recovery of Cu, Pb, Cd, and Zn from a simulated municipal solid waste incineration ash leachate. By varying the control of the BES, the four metals could sequentially be recovered from a mixed solution by reduction on a titanium cathode. First, the cell voltage was controlled at zero, which allowed recovery of Cu from the solution without an electrical energy input. Second, the cathode potential was controlled at -0.51 V to recover Pb, which required an applied voltage of about 0.34 V. Third, the cathode potential was controlled at -0.66 V to recover Cd, which required an applied voltage of 0.51 V. Finally, Zn was the only metal remaining in solution and was recovered by controlling the anode at +0.2V to maximize the generated current. The study is the first to demonstrate that a BES can be used for cathodic recovery of metals from a mixed solution, which potentially could be used not only for ash leachates but also for e.g. metallurgical wastewaters and landfill leachates.
Division of Water Environment Technology, Department of Civil & Environmental Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden. oskar.modin@chalmers.se
Oskar
O
Modin
Xiaofei
X
Wang
Xue
X
Wu
Sebastien
S
Rauch
Karin Karlfeldt
KK
Fedje
D019149:Bioreactors; D060729:Coal Ash; D004566:Electrodes; D004572:Electrolysis; D017745:Incineration; D007220:Industrial Waste; D019216:Metals, Heavy / Q000737:chemistry / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D012722:Sewage; D012996:Solutions; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*
D060729:Coal Ash; D007220:Industrial Waste; D019216:Metals, Heavy; D012722:Sewage; D012996:Solutions; D062065:Wastewater; D014874:Water Pollutants, Chemical