Enhanced bioelectricity generation of air-cathode buffer-free microbial fuel cells through short-term anolyte pH adjustment

Short-term initial anolyte pH adjustment can relieve the performance deterioration of the single-chamber air cathode buffer-free microbial fuel cell (BFMFC) caused by anolyte acidification. Adjusting the initial anolyte pH to 9 in 5 running cycles is the optimum strategy. The relative abundance of the electrochemically active Geobacter in the KCl-pH 9-MFC anode biofilm increased from 59.01% to 75.13% after the short-term adjustment. The maximum power density (P-max) of the KCI-pH 9-MFC was elevated from 316.4 mW.m(-2) to 511.6 mW.m(-2), which was comparable with that of the PBS-MFC And, after the short-term adjusting, new equilibrium between the anolyte pH and the anode biofilm electrochemical activity has been established in the BFMFC, which ensured the sustainability of the improved bioelectricity generation performance. (C) 2017 Elsevier B.V. All rights reserved.