Abstract
► The microbes from anaerobic sludge were various and easy to obtain. ► The toxic and refractory N-heterocyclic compounds were used as carbon sources, which indicated MFC technology could be linked with wastewater treatment in practical applications. ► The metabolic pathways of N-heterocyclic compound under anaerobic conditions were investigated by GC/MS, which provide some new information for biological treatment of these target compounds (pyridine, quinoline, indole).
Growing energy needs and concerns about environmental pollution have stimulated increased interest in the research and application of microbial fuel cell (MFC) systems. The objective of this study was to investigate possible electricity production with nitrogenous heterocyclic (N-heterocyclic) compounds degradation in the MFCs. Two-chamber MFCs were designed and inoculated with anaerobic sludge acclimated for several months. The experiments were conducted to test the potential for biodegradation of refractory organic matters and electricity generation using representative N-heterocyclic compounds such as pyridine, quinoline and indole. A maximum voltage of 524
mV, 494
mV, 413
mV (based on an external resistance of 1000
Ω), and the corresponding maximum power densities of 228.8
mW
m
−2, 203.4
mW
m
−2, 142.1
mW
m
−2 were obtained from pyridine, quinoline, and indole, respectively. Meanwhile, the maximum degradation efficiency of these substrates and COD (chemical oxygen demand) removal were up to 90% and 88%, respectively. The metabolic intermediate products were detected by GC/MS analyses of the anode solution. These results indicated that N-heterocyclic compound may be used as the MFC fuel in practical applications of wastewater treatment.