화학공학소재연구정보센터
International Journal of Energy Research, Vol.41, No.14, 2345-2355, 2017
Enhanced bioremediation of toxic metals and harvesting electricity through sediment microbial fuel cell
Performance of sediment microbial fuel cells (SMFCs) with aerated (A-SMFC) and nonaerated (NA-SMFC) cathodes was evaluated at different operating conditions in toxic metal removal and power generation. The A- and NA-SMFC open-circuit voltages were respectively about 665 and 275mV, with quite steady performances for 120days. The cell design points of both SMFCs were calculated by implementing polarization curves, and they were at 1k (power density 8.1mW/m(2) and current density 0.0504mA/m(2) with voltage 150mV) for NA-SMFC and 100 (power density 252.81mW/m(2) and current density 0.954mA/m(2) with voltage of 275mV) for A-SMFC, respectively. Cathode potentials were at 30k 290mV (NA-SMFC) and 500mV (A-SMFC). As to the anode, at 30K, it was -180mV (NA-SMFC) and 190mV (A-SMFC). The voltammetry profiles of A-SMFC showed maximum current (forward scan, 22.7A; reverse scan, -19.4A) followed by NA-SMFC (forward scan, 11.3A; reverse scan, -9.5A). The cell design points of A-SMFC and NA-SMFC were altered after pH and temperature amendments at 200 and 700, respectively. As to metal removal rate, the maximum arsenic cadmium and lead removal was observed in A-SMFC at pH 7.0 (77.70%, 90.86%, and 83.91%) and 45 degrees C (66.22%, 79.03%, and 71.17%). Scanning electron microscopy confirmed, at pH 7.0 and 45 degrees C, an optimal biofilm growth at cathode and anode graphite of both SMFCs. After 120days of operation, genomic DNA was extracted from biofilms and analyzed for rDNA 16S sequences. Similarity search was performed by using Basic Local Alignment Search Tool algorithm against the National Center for Biotechnology Information Gen Bank showing Pseudomonas spp. dominance at both anode and cathode. The results revealed that the A-SMFC system could be employed as an effective and long-term tool for power generation as well as stimulated bioremediation of the polluted sediments.