Electricity generation influenced by nitrogen transformations in a microbial fuel cell: assessment of temperature and external resistance

Author(s)

Cano, Vitor ^[1] ; Cano, Julio ^[1] ; Nunes, Sabrina C. ^[1] ; Nolasco, Marcelo A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Arts Sci & Humanities, Ave Arlindo Bettio 1000, BR-03828000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: RENEWABLE & SUSTAINABLE ENERGY REVIEWS; v. 139, APR 2021.
• Web of Science Citations: 0

Abstract

Microbial fuel cells (MFC) generate clean energy from organic wastes. This study reports the development and application of novel lab-scale MFC with granular activated carbon-modified electrode fed with synthetic sugarcane vinasse. Biological activity involving nitrogen in the cathode chamber was assessed as a strategy to improve cathode performance under different temperatures (similar to 25, 35 and 55 degrees C) and external resistance (13 and 300 Omega). High organic matter removal (>90%) was obtained regardless of the condition applied. Nitrification occurred in the cathode chamber at temperature up to 35 degrees C; this resulted in a decrease in pH to <7, which favored the cathode performance. The anode, applied at 35 degrees C and 55 degrees C, presented lower internal resistance and more negative potentials; this shows that the temperature reduced the anode overpotentials. The application of 13 Omega external resistance promoted higher electrogen activity, which resulted in coulombic efficiency up to 12.6 +/- 2.4% against 1.9 +/- 0.2% at 300 Omega. The combination of the proposed configuration, operation and electrode materials yielded maximum power density of 41.3 W m(-3), which is higher than values reported by other studies with similar electrode materials, reactor configuration (not stacked) and substrate composition (diversified). The findings contribute to the development of scalable renewable energy generation systems based on combination of biochemical and bioelectrochemical processes in wastewater treatment. (AU)

• FAPESP's process: 17/10325-5 - Microbial fuel cell for the treatment of high organic load effluents: analysis of organic matter removal and generation of energy
• Grantee: Julio Cano
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/24524-0 - Development of microbial fuel cell prototype for bioeletricity production in wastes treatment
• Grantee: Marcelo Antunes Nolasco
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants