On the effect of different configurations in air-cathode MFCs fed by composite food waste for energy harvesting

In this work, experimental results on the behavior of single chamber air-cathode microbial fuel cells, fed by composite food waste, are illustrated. Specific interest has been focused on the presence/absence of a Nafion membrane, the influence of horizontal/vertical cell layout and on the amount of water inside the cells, in order to evaluate the performances in different configurations. A remarkable increment of performances is observed when a Nafion membrane is used or when the composite food waste has a low Solid-to-Liquid ratio. Results showed that values of about 380-550 mV, for the open circuit voltage, and power density of 16-27 mW/m2 are achieved when Nafion/Vertical or Nafion/Conditioned/Horizontal configurations are used. The most limiting factors to power generation can be attributed to the high water losses, when Nafion is absent, and to the high internal resistance, when a thick cathode is used instead of a thin carbon cloth.