Methanogenesis suppression in microbial fuel cell by aluminium dosing

Abstract

Reduction in power production due to loss of substrate to methanogens makes methanogenesis a serious performance limitation in microbial fuel cell (MFC). Aluminium (Al) due to its antibacterial properties easily affects the methanogens, which have a thinner cell membrane and slower growth rate. The effect of Al in suppressing methanogens was thus studied by adding 5 mg/L of aluminium sulphate in anolyte of the treated MFC (MFCT). Reduced COD removal efficiency of 86.11 � 1.3% was observed in MFCT which was lower than that observed (96.25 � 1.7%) in the control MFC (MFCC) operated without Al addition. An average volumetric power density of 1.84 � 0.40 W/m3 was observed in MFCT whereas the average volumetric power density observed in MFCC was 1.54 � 0.46 W/m3. An internal resistance of 195 ? was observed in MFCT, which was significantly lower than 349 ?, as observed in MFCC. The coulombic efficiency (CE) of MFCT was found to be 2.5 times higher than the CE of MFCC. This improved performance of MFCT denoted better biocatalytic activity and electron transfer capability of anodic biofilm of MFCT than MFCC. Higher current generation during electrochemical analysis showed better electron discharge at the anode and lesser electron loss at the interface of electrode and electrolyte. � 2019 Elsevier B.V.