Membrane-less microbial fuel cell: effect of pH on the electricity generation powered by municipal food waste

Abstract

Fossil fuels have supported the industrialization and economic growth of countries during the past centuries and it is clear that they cannot indefinitely sustain in a longer time. In this study, membrane-less microbial fuel cell (ML-MFC) with mediators-less and air cathode had potential solution to generate electricity power and at the same time could reduce the abundant of food waste (1.64 kg/daily, around 8 tonnes/year) which dumped in the landfill and it's cost effective device. The ML-MFC operated electrochemically incorporate electrogenic bacteria (EB) acted as a biocatalyst in order to produce electricity. The performance and optimization performance of food waste was evaluated using one-factor-at-a-time (OFAT) method and it was focused to pH for power generation. To determine the generated electricity the polarization curve was used to evaluate the performance of ML-MFC. The chemical oxygen demand (COD) of food waste was studied. The optimization of pH condition in ML-MFC was ranging from 7 to 9. Results showed that pH 8 was the optimum pH for EB strain, Bacillus Subtilis, with the high voltage (807 mV), EB biomass (15.46 mg/L), and power density (373.3 mW/m2) generated. Clearly the pH environment condition affected the efficiency of ML-MFC performance. The increase in EB biomass also increased the voltage in the ML-MFC, proving that EB biomass and voltage were associated with growth.