Increasing power generation and energy efficiency with modified anodes in algae-supported microbial fuel cells

In this study, an algae-assisted microbial fuel cell (MFC) was developed to both treat horse manure wastewater and generate electricity. Carbon felt (CF) and graphite felt (GF) electrodes were modified with carbon nanotube (MWCNT) and nitric acid (HNO3) to prepare different anodes and their effects on MFC performance were evaluated. The power density of 59 mW/m2 obtained with the CF-HNO3 anode showed the highest value among all tested systems and was found to be 2.45 and 2.13 times higher than unmodified CF and GF anodes, respectively. Moreover, a 17% higher performance was achieved compared to the GF-HNO3 anode. The higher performance of CF-HNO3 compared to GF-HNO3 can be attributed to the higher surface area of the carbon felt, improved proton conduction, and increased electrochemical activity after treatment with nitric acid. The modified CF-MWCNT and GF-MWCNT anodes produced power densities of 55 mW/m2 and 45 mW/m2, respectively. The Coulombic efficiency (CE) values obtained were in line with these results. The results reveal that nitric acid modification significantly increases the power output of MFCs by providing accelerated electron transfer on biofilms. This simple and effective method offers a new approach to develop low-cost and high-performance electrode materials for MFCs. Moreover, the analysis of algal biomass from the cathode chamber is in line with the existing literature and makes an important contribution towards sustainable energy solutions. The study stands out as a promising step towards the scalability and commercialization of MFCs. Furthermore, the findings can contribute to economic feasibility through low-cost modification techniques and support environmental sustainability. The findings contribute to economic feasibility and support environmental sustainability through low-cost modification techniques. Future studies can support the wider adoption of MFCs for industrial applications by investigating the effects of these modifications on long-term performance and compatibility with different wastewater types. This could accelerate the transition to sustainable energy solutions by promoting the wider use of MFCs in power generation and wastewater treatment.