Influence of carbon anode properties on performance and microbiome of Microbial Electrolysis Cells operated on urine

Anode performance of Microbial Electrolysis Cells (MECs) fed with urine using different anodes, Keynol (phenolic-based), C-Tex (cellulose-based) and PAN (polyacrylonitrile-based) was compared under cell potential control (1st assay) and anode potential control (2nd assay). In both assays, C-Tex MEC outperformed MECs using Keynol and PAN. C-Tex MEC under anode potential control (−0.300 V vs. Ag/AgCl) generated the highest current density (904 mA m−2), which was almost 3-fold higher than the Keynol MEC and 8-fold higher than the PAN MEC. Analysis of anodes textural, chemical and electrochemical characteristics suggest that the higher external surface area of C-Tex enabled higher current density generation compared to Keynol and PAN. Anodes properties did not influence significantly the microbial diversity of the developed biofilm. Nonetheless, C-Tex had higher relative abundance of bacteria belonging to Lactobacillales and Enterobacteriales suggesting its correlation with the higher current generation.