Low pH, high salinity: Too much for microbial fuel cells?

By N. Jannelli, R. A. Nastro, V. Cigolotti, M. Minutillo, G. Falcucci. 2016

82 citations recorded by the source corpus.

Abstract Twelve single chambered, air-cathode Tubular Microbial Fuel Cells (TMFCs) have been filled up with fruit and vegetable residues. The anodes were realized by means of a carbon fiber brush, while the cathodes were realized through a graphite-based porous ceramic disk with Nafion membranes (117 Dupont). The performances in terms of polarization curves and power production were assessed according to different operating conditions: percentage of solid substrate water dilution, adoption of freshwater and a 35 mg/L NaCl water solution and, finally, the effect of an initial potentiostatic growth. All TMFCs operated at low pH ( pH = 3.0 ± 0.5 ) , as no pH amendment was carried out. Despite the harsh environmental conditions, our TMFCs showed a Power Density (PD) ranging from 20 to 55 mW/m2 kgwaste and a maximum CD of 20 mA/m2 kgwaste, referred to the cathodic surface. COD removal after a 28-day period was about 45%. The remarkably low pH values as well as the fouling of Nafion membrane very likely limited TMFC performances. However, a scale-up estimation of our reactors provides interesting values in terms of power production, compared to actual anaerobic digestion plants. These results encourage further studies to characterize the graphite-based porous ceramic cathodes and to optimize the global TMFC performances, as they may provide a valid and sustainable alternative to anaerobic digestion technologies.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Environmental Engineering

View Paper: https://www.semanticscholar.org/paper/6a48d151115dbb7dd5c55889b7a5d29b0abcff31