Influence of glass wool as separator on bioelectricity generation in a constructed wetland-microbial fuel cell.

To figure out the impact of the separator on the electrical performance of the newly established constructed wetland-microbial fuel cell (CW-MFC), two parallel upflow CW-MFC systems, with and without glass wool (GW), were set up in this study. System performances in terms of bioelectricity production were monitored for more than 4 months. Results showed that the highest voltage was achieved in non-separator (NS) system (465.7 ± 4.2 mV with electrode spacing of 5 cm), which is 48.9% higher than the highest value generated in GW system (312 ± 7.0 mV with electrode spacing of 2 cm). The highest power density was produced in NS system (66.22 mW/m2), which is 3.9 times higher than the value in GW system (17.14 mW/m2). The diffusion of oxygen from the open air was greatly hindered by the biofilm formed under the cathode. This kind of biofilm can be severed as the "microbial separator", playing the same role in a real separator.