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

I Merino-Jimenez; O Obata; G Pasternak; I Gajda; J Greenman; I Ieropoulos

doi:10.1016/j.procbio.2020.10.014

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

Process Biochem. 2021 Feb:101:294-303. doi: 10.1016/j.procbio.2020.10.014.

Authors

I Merino-Jimenez^{1

2}, O Obata³, G Pasternak^{1

2}, I Gajda³, J Greenman⁴, I Ieropoulos^{3

4}

Affiliations

¹ Laboratory of Microbial Electrochemical Systems, Faculty of Chemistry, Wroclaw University of Science and Technology, 50-370, Wroclaw, Poland.
² Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Spanish National Research Council, C/ del Til·lers, Campus Universitat Autònoma de Barcelona (UAB), 08193, Bellaterra, Barcelona, Spain.
³ Bristol BioEnergy Centre, Bristol Robotics Laboratory, University of the West of England, BS16 1QY, UK.
⁴ Biological, Biomedical and Analytical Sciences, University of the West of England, BS16 1QY, UK.

Abstract

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.

Keywords: Catholyte production; Ceramic membrane; Electroosmotic drag; Energy from waste; Microbial Fuel Cell (MFC); Urine; Urine treatment.