Biocathode of microbial fuel cells based on nitrate-reducing strains of Pseudomonas aeruginosa

Abstract

One approach to eliminating the loss of electricity from overvoltage at the cathode electrode in the technology of microbial fuel cells (MFCs) is the use of microorganisms as biological catalysts for cathodic processes in MFCs. In this paper, the efficiency of MFC with biocathodes based on nitrate-reducing strains of Pseudomonas aeruginosa (3-SW) and (20-SW) isolated from wastewater of the Angarsk Petrochemical Plant (APP) is estimated. Electrical indicators of MFC with biocathodes with P. aeruginosa (20-SW) and P. aeruginosa (3-SW) strains were higher than similar MFC with nitrate cathodes without microorganisms. At the same time, MFC with a biocathode with a P. aeruginosa strain (20-SW) was more effective than a MFC with a biocathode based on P. aeruginosa (3-SW), as in terms of the generated electricity (voltage and current strength of an MFC with P. aeruginosa (20-SW) – 478 ± 12 mV and 1361 ± 133 μA, with (3-SW) – 380 ± 10 mV and 1011 ± 10 μA, respectively), and the degree of elimination of nitrate (from 147.96 ± 9.77 to 0.00 mg/dm3 in the MFC biocathode with P. aeruginosa (20-SW) and from 141.59 ± 11.82 to 54.66 ± 2.39 mg/dm3 in the biocathode with P. aeruginosa (3-SW) during the 96 h experiment). Thus, the conducted studies make it possible to recommend a culture of P. aeruginosa (20-SW), isolated from APP wastewater, to obtain MFC biocathode with its simultaneous use for nitrate wastewater treatment.