Maximising energy harvest from constructed wetland-microbial fuel cell using capacitor engaged duty cycling strategy

Abstract

Although the newly established constructed wetland-microbial fuel cell (CW-MFC) has attracted considerable attention for wastewater treatment and electricity generation. However, the integration of MFC into CWs always faces a large portion of energy losses due to the existence of higher internal resistances. Here, a novel working strategy for energy harvesting from CW-MFC system, named as capacitor engaged duty cycling (CDC) strategy, was proposed and tested. Results showed that with duty cycle (D) value of 31.58% (D = 31.58%), the effective charge obtained from CDC strategy is 11.9% higher than the conventional continuous loading (CL) mode. Further lower D value to 18.75%, the total charge harvested increased about 17.57%. In addition, CDC operation mode also shows advantages over higher internal resistance system. This operation strategy has the potential to minimize the energy losses with a suitable D value. Overall, this method showed a simple but effectively way to maximize the energy harvesting from CW-MFC system.