Microbial fuel cell technology for clean energy production from palm oil mills effluent liquid waste

The microbial fuel cell (MFC) technology utilizes microbial metabolism for energy conversion. This study uses palm oil mill effluent (POME) as a substrate, the effective microorganism (EM4), and Escherichia coli (E. coli) as microorganisms in a dual-chamber MFC system. This study aims to analyze the effect of bacteria on the electrical energy produced from the POME substrate, analyze changes in chemical oxygen demand (COD) and biological oxygen demand (BOD) in the waste, and analyze the effect of incubation time on the resulting power density value. pH, voltage (V), and electric current strength (mA) were observed at predefined time intervals over 36 h (0-36 h); while the biomass of Escherichia coli and EM4 was calculated accordingly. COD and BOD were tested before and after the microbial fuel cell (MFC) process. The maximum voltage and current values for E. coli occurred at the 26th hour, with a bacterial concentration of 25% (v/v), yielding 1.617 V and 0.844 mA, respectively, with a biomass amount of 0.3118 g mL^-1 and a power density value of 174.075 mWatt m^-2. However, the 20% (v/v) E. coli treatment resulted in the most pronounced reductions in BOD (57%) and COD (42%) among all tested conditions. The results further support the integration of microbial fuel cell technology into circular bioeconomy frameworks, where POME can be treated not only as waste but also as a resource for renewable energy generation.