Electricity Generation From Bio-Treatment of Sewage Sludge Plant Microbial Fuel Cells With Oryza Sativa

Plant microbial fuel cells (PMFCs) are emerging biotechnological devices that support renewable energy sources. PMFCs can be integrated with various substrates, such as sewage sludge, municipal compost, or even fertilizer, to enhance bioelectricity production. In this study, the performance of paddy (Oryza sativa) PMFCs was evaluated using municipal wastewater treatment sewage sludge and the PMFC performance was compared with natural paddy soil. Graphite fiber electrodes containing 3 kg of paddy soil and sewage sludge were installed in each PMFC system. All PMFCs were conducted on a balcony equipped with a rain shelter, where sunlight, temperature, and humidity varied for 90 days. The voltage outputs for the PMFC and sewage-PMFC reached maximum power outputs of 680±28.31 mV (27.78 mW/m²) and 562.50±69.22 mV (19.01 mW/m²), respectively. Notable decreases in pH and electrical conductivity (EC) were observed throughout the experiment and were attributed to bioelectrochemical processes within the PMFCs. The dominant microbial phyla identified in both PMFCs were Proteobacteria, Bacteroidetes, and Chloroflexi. This study demonstrated that the power generation of PMFCs can be enhanced by bio-treatment of sludge and various plants can be used for future sludge treatment. Overall, this research demonstrated the potential of plant microbial fuel cells for further improving energy recovery from sewage sludge generated by the biological treatment process.