Potency of Yeast – Microalgae Spirulina Collaboration in Microalgae-Microbial Fuel Cells for Cafeteria Wastewater Treatment

The effect of yeast Saccharomyces cerevisiae combined with Spirulina platensis in microalgae-microbial fuel cells (MMFCs) on the treatment of cafeteria wastewater to generate electricity and produce microalgae biomass was investigated. A treated cafeteria wastewater which has Chemical Oxygen Demand (COD) of 33,500 mg·L⁻¹ was used as the substrate and compared with commercial sugar as the control sample. During the process, the substrate was changed partially after 5 days and resulted power density of 73.7±4.57 mW·m⁻². The COD of cafeteria wastewater removed by 30.1% from its initial concentration and then decreased by 40.8% after substrate partially replaced. Increasing optical density of microalgae in the cathode side from 0.6 to 1.37 could improve the oxygen reduction reaction which useful for electricity production. The result showed that cafeteria wastewater has feasibility as the substrate of yeast – Spirulina MMFCs to gain bioelectricity which can be used as an alternative electricity source for developing countries, for example, Indonesia.