Improving Bioelectricity by Optimizing the Use of Electrodes in Photosynthetic Microbial Fuel Cells Based on the Algae Scenedesmus sp. and Shrimp Cultivation Waste

Rapid economic growth and increasing electrical energy consumption have raised significant challenges to the provision of sustainable electrical energy. This research aims to examine the effect of variations in the population density of microalgae and the type of electrode (graphite and nickel) on the electrical voltage produced. This research was carried out experimentally using a randomized block design (RAK) consisting of 5 treatments and 3 repetitions. Electrical voltage data was taken every 60 minutes for 12 hours (6 hours of light and 6 hours of dark) for all treatments. The results showed that the use of different types of electrodes in the PMFC circuit did not affect the electrical voltage produced because both electrodes produced voltage electricity with a difference that is not much different, namely for graphite electrodes between 38.1 mV – 135.6 mV in the light phase and between 16.7 mV – 144.1 mV in the dark phase, while for nickel electrodes it is between 18.2 mV – 135.4 mV in the light phase and between 18.3 mV – 156 mV in the dark phase. Variations in population density of the microalgae Scenedesmus sp. used in the PMFC circuit have a significant effect (P<0.05) on the electrical voltage produced, namely in the light phase of treatment (P4) 2x10⁷ it is 131.53 ± 25.12 mV for graphite electrodes and 137.90 ± 17.26 mV for nickel electrodes, while in the dark phase treatment (P3) 2x10⁶ it was 168.70 ± 18.55 mV for graphite electrodes and 139.70 ± 27.35 mV for nickel electrodes.