Biofilm (bio-catalyst) formation on the working electrode in a microbial fuel cell

A microbial fuel cell (MFC) is a bioelectrochemical reactor in which microorganisms, feeding on organic matter, generate electricity. In such a reactor, microorganisms active on the anode form a biofilm, whose activity is a key factor determining the performance of the MFC. Biofilm also forms in water transfer installations, in substrate transfer installations in biogas plants, etc. However, in such cases such biofilm can be a source of microbiological infections or corrosion. In addition, such biofilm is composed of various microorganisms, not necessarily producing electrons. In the case of biofilm formed on the electrode in MFC, the most important thing is to build a thin layer of biofilm from electron-producing microorganisms. This paper discusses the theoretical part of biofilm (bio-catalyst) formation and carries out the procedure of building a biofilm on a carbon electrode. It has been shown that to obtain a biofilm capable of generating electricity, at least three start-ups are necessary before the electrode reaches the appropriate operating parameters. After obtaining a ready-to-use electrode with an active biofilm, measurements of electricity generation in the MFC were carried out. The results demonstrated the effectiveness of performing multiple startups to achieve a suitable working electrode with an active biofilm.