Effect of microbial fuel cell operation time on the disinfection efficacy of electrochemically synthesised catholyte from urine

• Published in: Process biochemistry (1991) Vol. 101; pp. 294 - 303
• Main Authors: Merino-Jimenez, I., Obata, O., Pasternak, G., Gajda, I., Greenman, J., Ieropoulos, I.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2021; Elsevier BV; Elsevier Applied Science
• Subjects: Alternative energy; Biochemical fuel cells; Biocides; Catholyte production; Ceramic membrane; Composition; Disinfection; E coli; Electricity; Electricity generation; Electrochemistry; Electroosmotic drag; Energy from waste; Energy sources; Flow cytometry; Fuel cells; Fuel technology; Microbial Fuel Cell (MFC); Microorganisms; pH effects; Renewable energy; Resource recovery; Sustainability; Urine; Urine treatment; Waste management; Wastewater treatment; Water reuse; Water stress; Water treatment; Energy from waste; Urine; Ceramic membrane; Microbial Fuel Cell (MFC); Electroosmotic drag; Urine treatment; Catholyte production
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2020.10.014

[Display omitted] •The MFC with the thickest ceramic membrane produced the best quality catholyte.•MFC operation time contributes to the catholyte quality and killing properties.•Catholyte from ceramic MFC (10 mm) reached pH 11 at day 42 and eradicated E. coli. Microbial fuel cells (MFCs) offer an excellent solution to tackle some of the major challenges currently faced by humankind: sustainable energy sources, waste management and water stress. Besides treating wastewater and producing useful electricity from urine, ceramic MFCs can also generate biocidal catholyte in-situ. It has been proved that the electricity generation from the MFCs has a high impact in the catholyte composition. Therefore, the catholyte composition constantly changes while electricity is generated. However, these changes in catholyte composition with time has not yet been studied and that could highly contribute to the disinfection efficacy. In this work, the evolution of the catholyte generation and composition with the MFC operation time has been chemically and microbiologically evaluated, during 42 days. The results show an increase in pH and conductivity with the operation time, reaching pH 11.5. Flow cytometry and luminometer analyses of bioluminescent pathogenic E. coli exposed to the synthesised catholyte revealed killing properties against bacterial cells. A bio-electrochemical system, capable of electricity generation and simultaneous production of bactericidal catholyte from human urine is presented. The possibility to electrochemically generate in-situ a bacterial killing agent from urine, offers a great opportunity for water reuse and resource recovery for practical implementations.