Bioelectricity generation through palm oil mill effluent treatment using mixed culture exoelectrogens in microbial fuel cell (MFC) / Khairul Baqir AlKhair Khairul Amin

MFC technologies represent the newest approach for generating electricity (bio-electricity generation) from biomass using bacteria. Bio-electricity generations by MFCs have gained considerable attention due to its integration with wastewater treatment. This study consist of 4 main stages which are bacteria isolation, bacteria identification, optimization of MFC and optimized MFC electrochemical operation. In bacteria isolation stage, MFC device were used to obtain exoelectrogens from POME mixture in a form of biofilm. Bath sonication were used to detach bacterial cells (biofilm) from the anode. The isolation process were separated into 3 different pH values that represent pH value ranges in fermentative pathway’s phases which is acidogenic (pH 5.5 ±0.2), acetogenic (pH 6.8 ±0.2) and methanogenic (pH 8.0 ±0.2). Bacteria were successfully isolated and acetogenic was the best isolation condition for bacteria to metabolize. In bacteria identification, metagenomics accomplished identified all the exoelectrogens mixed culture from 4 different sources of POME samples. 181 bacteria species were detected. For sample from TSB broth (S1) and BHI broth (S2), the most dominance bacteria species are Proteus and Sporanaerobactor. TSB MFC (S3) and BHI MFC (S4), the most dominance bacteria species is Alcaligenes. In optimization of MFC, the works were separated into two parts. The first part analyze variable of bacteria’s broth, pH controller and external resistor, and the second part were temperature, electrode material and fermentation time. In the first part, DOE experimental result shows that the best interaction between these 3 factors is (-+-) interaction which is the interaction between TSB broth, Ca(OH)2 as pH controller and resistant of 200 Ω, with the effect value of 24.56. In second part, (+++) is the best interaction which are the temperature of 37 0C, carbon cloth and fermentation’s time of 120 hours. Finally, the new MFC configuration were set into a final stage of electrochemical analysis evaluation to examine its improvements after successfully being optimized. The MFC configuration modification is a huge success by comparing it with previous study MFC studies. The power density produced in this study is 311.19 mW/m2 with the current density of 919.73 mA/m2. The new MFC configuration managed to treat the POME wastewater up to 82.42 %.