Microbial fuel cell (MFC) using commercially available unglazed ceramic wares: Low-cost ceramic separators suitable for scale-up

Abstract

This study aimed to evaluate the influence of commercially available unglazed wall ceramic (UGWC) and unglazed floor ceramic (UGFC) separators with different thickness and porosity on the performance of dual-chamber microbial fuel cells (MFCs). These MFCs were operated under continuous condition using domestic wastewater. The UGWC-based MFC produced higher maximum power density (321 mW/m2 with a thickness of 9 mm) than UGFC-based MFC (106.89 mW/m2 with a thickness of 3 mm) due to lower internal resistance. Power generation using both types of separators was lower than that of obtained using the Nafion 117 membrane as control (602 mW/m2). The maximum average coulombic efficiencies (CE) of the UGWC-based MFCs (with thickness levels of 6 and 9 mm) were 58% and 68%, respectively, which was more than that of UGFC-based MFCs and also control MFC (53%). Voltammetric analysis revealed that the maximum peak current of 6 mA was obtained for UGWC-based MFC which was in the order of control MFC (5.9 mA). The UGWC separators exhibited smaller ohmic and diffusion resistances of 57, 65 and 87 Ω in MFCs at the thickness levels of 3, 6 and 9 mm, respectively, compared to the UGFC separators with that of 164.27 and 366.23 Ω in MFCs at the thickness levels of 3 and 6 mm, respectively. UGWC separators because of their low production cost, high mechanical strength and increased output power density of the MFC proved to be a suitable alternative to replace with a costly polymeric membrane such as Nafion 117.