Nickel ion removal from wastewater using the microbial electrolysis cell

In this study, the microbial electrolysis cell (MEC) was examined for treatment of wastewater containing nickel ion (Ni(2+)). Effects of initial Ni(2+) concentrations in catholyte, pH values of catholyte, and applied voltages on MEC performance were determined. Results showed that the Ni(2+) removal efficiency with the MEC was three times higher than those with an electrolysis cell and a microbial fuel cell. Ni(2+) removal efficiencies decreased from 99 ± 0.6% to 33 ± 4.2% with the initial Ni(2+) concentrations from 50 to 1000 mg/L, while the mass removal of Ni(2+) increased consistently with the initial concentrations. Ni(2+) removal efficiencies in the MEC increased from 51 ± 4.6% to 67 ± 5.3% with the applied voltages from 0.5 to 1.1 V. These results demonstrate that the MEC can be an alternative process to effectively remove Ni(2+) from wastewater.