Effects of different cathode conditions on electricity generation and removal of heavy metal pollutants in CW-MFC

Abstract

The effect of treating copper-containing wastewater by CW-MFC technology was discussed. The power generation and wastewater purification efficiency of CW-MFC are affected by electrode spacing, cathode electrode area and influent copper concentration. Smaller electrode spacing may destroy the anaerobic environment in the wastewater, while larger electrode spacing will increase the total internal resistance of the system, resulting in a decrease in electricity generation efficiency. With the increase of cathode area, the removal efficiency of pollutants in wastewater will be improved. However, when the cathode area is too large, it will increases the internal resistance of the system, which will affect the electric production performance. When the best electrode spacing is 10 cm and the cathode electrode area is 75 cm2, CW-MFC shows the best power generation and wastewater purification effect. When the concentration of copper in the wastewater increases, the power generation and wastewater purification efficiency of the system will also increase. When the copper concentration reaches 50 mg/L, the system shows the best effect, its open circuit voltage reaches the maximum, and the removal rate of copper and total nitrogen is also the highest. When the concentration of copper in wastewater reaches 100 mg/L, the microbial activity is inhibited, resulting in a significant decline in the performance of CW-MFC.