Mineralization of pentachlorophenol with enhanced degradation and power generation from air cathode microbial fuel cells

The combined anaerobicaerobic conditions in air-cathode single-chamber MFCs were used to completely mineralize pentachlorophenol (PCP; 5?mg/L), in the presence of acetate or glucose. Degradation rates of 0.140?+/-?0.011?mg/L-h (acetate) and 0.117?+/-?0.009?mg/L-h (glucose) were obtained with maximum power densities of 7.7?+/-?1.1?W/m3 (264?+/-?39?W/m2, acetate) and 5.1?+/-?0.1?W/m3 (175?+/-?5?W/m2, glucose). At a higher PCP concentration of 15?mg/L, PCP degradation rates increased to 0.171?+/-?0.01?mg/L-h (acetate) and 0.159?+/-?0.011?mg/L-h (glucose). However, power was inversely proportional to initial PCP concentration, with decreases of 0.255?W/mg PCP (acetate) and 0.184?W/mg PCP (glucose). High pH (9.0, acetate; 8.0, glucose) was beneficial to exoelectrogenic activities and power generation, whereas an acidic pH?=?5.0 decreased power but increased PCP degradation rates (0.195?+/-?0.002?mg/L-h, acetate; 0.173?+/-?0.005?mg/L-h, glucose). Increasing temperature from 22 to 35 degrees C enhanced power production by 37% (glucose) to 70% (acetate), and PCP degradation rates (0.188?+/-?0.01?mg/L-h, acetate; 0.172?+/-?0.009?mg/L-h, glucose). Dominant exoelectrogens of Pseudomonas (acetate) and Klebsiella (glucose) were identified in the biofilms. These results demonstrate that PCP degradation using air-cathode single-chamber MFCs may be a promising process for remediation of water contaminated with PCP as well as for power generation. Biotechnol. Bioeng. 2012;109: 22112221. (c) 2012 Wiley Periodicals, Inc.