Assessment of expanded polystyrene as a separator in microbial fuel cell.

Separators are considered as an important component in microbial fuel cells (MFCs) to facilitate ion transport and to prevent electrode short circuiting. In the present study, expanded polystyrene (EPS) was evaluated for the first time as a separator in a single-chamber air cathode and dual chamber aqueous cathode MFCs. The characteristics and performance of EPS were analyzed and compared with other conventionally used separators used in MFCs and was found to be competitive. Initially, the EPS was less impermeable to protons, resulting in delayed process startup (17 days) and stabilization (57 days), but gradually exhibited improved and stable performance. In the air cathode MFC with the EPS as the separator and domestic wastewater as the substrate, power production was 391 mW/m2, while power output of the aqueous cathode MFC was 328 mW/m2. The characteristics and cost analysis of EPS indicate that it can be a potential candidate as a separator in scaled-up MFC applications.