Selective recovery of Cu2+ and Ni2+ from wastewater using bioelectrochemical system

Abstract

As the bioelectrochemical system, the microbial fuel cell (MFC) and the microbial electrolysis cell (MEC) were developed to selectively recover Cu2+ and Ni2+ ions from wastewater. The wastewater was treated in the cathode chambers of the system, in which Cu2+ and Ni2+ ions were removed by using the MFC and the MEC, respectively. At an initial Cu2+ concentration of 500 mg ·L−1, removal efficiencies of Cu2+ increased from 97.0%± 1.8% to 99.0%±0.3% with the initial Ni2+ concentrations from 250 to 1000 mg·L−1, and maximum power densities increased from 3.1±0.5 to 5.4±0.6W·m−3. The Ni2+ removal mass in the MEC increased from 6.8±0.2 to 20.5±1.5 mg with the increase of Ni2+ concentrations. At an initial Ni2+ concentration of 500 mg·L−1, Cu2+ removal efficiencies decreased from 99.1%±0.3% to 74.2%±3.8% with the initial Cu2+ concentrations from 250 to 1000 mg ·L−1, and maximum power densities increased from 3.0±0.1 to 6.3±1.2W·m−3. Subsequently, the Ni2+ removal efficiencies decreased from 96.9%±3.1% to 73.3%±5.4%. The results clearly demonstrated the feasibility of selective recovery of Cu2+ and Ni2+ from the wastewater using the bioelectrochemical system.