Kinetics of substrate degradation and electricity generation in anodic denitrification microbial fuel cell (AD-MFC)

Effect of substrate concentration on substrate degradation and electricity generation in anodic denitrification microbial fuel cell (AD-MFC) was investigated over a broad range of substrate concentrations. Substrate degradation rates and power generation could be promoted with increasing substrate concentration in a certain range, but both of them would be inhibited at high substrate concentrations. Maximum denitrification rate of 1.26 +/- 0.01 kg NO--N/m(3) d and maximum output voltage of 1016.75 +/- 4.74 mV could be achieved when initial NO3--N concentration was 1999.95 +/- 2.86 mg/L. Based on Han-Levenspiel model, kinetics of substrate degradation and power generation in the AD-MFC were established. According to the kinetic model, the half-saturation coefficient and the critical inhibitory concentration for nitrate were more than 200 and 4300 mg/L, respectively. The results demonstrated that AD-MFC was capable of treating nitrate-containing wastewater and generating electricity simultaneously, and tolerant to high strength nitrate-containing wastewater. (C) 2013 Elsevier Ltd. All rights reserved.