Effect of concentrations of bacterial consortia in culture medium from wastewater in microbial fuel cells

Background and Objective: Microbial fuel cells (MFCs) are technology by which electricity is generated from microbes. Electricity can be generated by MFCs by using wastewater as a substrate. Bacterial consortia from wastewater have been widely used in MFCs. Bacteria degrade substrates, resulting in a difference in potential, which in turn generates electricity. This research aimed to analyze the potential of bacterial consortia and identify the best number of additional bacterial consortia cultured in nutrient broth containing tempeh wastewater as the primary glucose source. Materials and Methods: In this study, used wastewater from tempeh production with different concentrations of bacterial consortia in culture medium (0, 0.4, 1 and 10%). Voltage was recorded with a digital multimeter instrument for 50 h. Bacterial growth was assessed every 3 h at 486 nm with a spectrophotometer UV-Vis. The COD of tempeh wastewater was analyzed before and after the experiment with COD kits and heating it on a COD Digester Block for 2 h at 150EC. Statistical analysis method used in this study is monothetic analysis or one-factor-at-a-time method. Results: The study indicates that the nutrients present in tempeh wastewater can be used as an effective energy source for MFCs using bacterial consortia as a biocatalyst. Conclusion: The optimum voltage and power density generated was up to 291.1 mV and 66.33 mW mG2 following 1% culture medium and its coulombic efficiency reached 4.48%. In addition to generating electricity, MFCs can remove chemical oxygen demand (COD). The highest COD removal value reaches 42.97% when 10% of culture was used.