Utilization of Montmorillonite-Modified Earthenware from Bentonite-Ca as a Microbial Fuel Cell (MFC) Membrane Based on Tempe Liquid Waste as a Substrate

Abstract

<jats:p>Modifications of the Microbial Fuel Cell (MFC) membrane need to be carried out to increase its electric potential energy. This research aims to determine the effect of montmorillonite from bentonite-Ca as a composite in modified earthenware (GT), which is then used as a membrane of the MFC-based on tempe wastewater as substrate. The results obtained were compared to MFC that used pure earthenware membrane (GM). The ratio of bentonite-Ca and clay in GT was 50:50, while GM used 100% of clay. Characterizations of GT dan GM were performed using FTIR, XRD, and SAA. MFC testing was carried out for 24 hours, where every 2 hours, measurements of potential difference (V), current (A), and power density (W/cm2) were carried out. FTIR and XRD data showed an increase in montmorillonite content in GT, while SAA data showed a decrease in pore volume in GT. The decrease in pore volume GT occurs due to an increase in the number of trivalent cations (Al3+, Fe3+) and bivalent (Mg2+). These cations help transfer protons from the anode to the cathode, which causes a decrease in the potential difference and an increase in the current strength and the MFC-GT power density. The average difference between the decrease in potential difference from MFC-GM to MFC-GT is 0.043 V, while the increase in current is 0.022 mA, and the increase in power density is 0.163 mW/cm2.</jats:p>