Application of Magnetite-nanoparticles and Static Magnetic Field on a Microbial Fuel Cell in Anaerobic Digestion

The selectivity of catalytic materials suitable for oxygen reduction potential of bio-electrochemical systems is very affluent. Therefore, exploring magnetite and static magnetic field as alternative option to promote microbial electron transfer comes in handy. In this study, the application of magnetite-nanoparticles and a static magnetic field on a microbial fuel cell (MFC) in anaerobic digestion was investigated. The experimental set-up included four 1 L biochemical methane potential tests: a) MFC, b) MFC with magnetite-nanoparticles (MFCM), c) MFC with magnetite-nanoparticles and magnet (MFCMM), and d) control. The highest biogas production obtained was 545.2 mL/g VSfed in the MFCMM digester, which was substantially greater than the 117.7 mL/g VSfed of the control. This was accompanied by high contaminant removals for chemical oxygen demand (COD) of 97.3%, total solids (TS) of 97.4%, total suspended solids (TSS) of 88.7%, volatile solids (VS) 96.1%, and color of 70.2%. The electrochemical efficiency analysis revealed greater maximum current density of 12.5 mA/m(2) and coulombic efficiency of 94.4% for the MFCMM. Kinetically, the cumulative biogas produced data obtained were well fitted on the modified Gompertz models and the greatest coefficient of determination (R-2=0.990) was obtained in the MFCMM. Therefore, the application of magnetite-nanoparticles and static magnetic field on MFC showed a high potential for bioelectrochemical methane production and contaminant removal for sewage sludge.

Automated summary

The use of magnetite nanoparticles and a static magnetic field in a microbial fuel cell (MFC) showed great potential in increasing the oxygen reduction potential and promoting microbial electron transfer. The MFCMM digester achieved the highest biogas production of 545.2 mL/g VSfed, which was significantly higher than the control. Moreover, the MFCMM exhibited high contaminant removal rates for various parameters. The application of magnetite nanoparticles and static magnetic field in MFC demonstrated promising results for bioelectrochemical methane production and contaminant removal.