Long-term performance of microbial fuel cell using manure as substrate

Long-term performance is of primary concern when considering the commercialized use of an microbial fuel cell (MFC). The long-term stability of MFC was studied using dairy manure as substrate over a testing time of 171 d. The results showed that the MFC could efficiently recover electricity from dairy manure during the long-time run, and the average power density was 6.77 W·m^-3±2.11 W·m^-3. On day 70, the polarization curve was measured, the open circuit voltage, internal resistance and maximum power density of MFC were 0.874 V, 22.1 Ω and 14.1 W·m^-3, respectively. The 30-day TCOD removal decreased with increasing test time, and the CE during the 121-150 d period reached 17.5%±3.3%. Phylogenetic analyses revealed that the dominant microbial communities in anodic biofilm were Proteobacteria (45%), Bacteroidetes (22%), Firmicutes (17%) and Actinobacteria (11%). At genera level, the bacteria with electricity production and (or) cellulose degradation ability, such as Clostridium and Cellulomonas were the abundant taxa.