Electricity production by Ochrobactrum-related strain CD-1 and pb2+ removal in dual-chamber microbial fuel cell

Abstract

<p>Dual-chamber microbial fuel cell (MFC) was constructed to treat heavy metal wastewater (Pb2+ solution). The results showed the maximum voltage, the maximum electric power density and pb2+ removal were 9.6 mV, 371.0 mV/m2 and 52.3% respectively. The effects of different cathode chamber environments on the production potential (V, volts) and Pb2+ removal rate of strained CD-1 were investigated. The results show that when the cathode chamber is soil, the maximum voltage is 8.88mV, and when the cathode chamber is solution, the maximum voltage is 12.11mV. The removal efficiency of heavy metals polluted from near to far from the electrode plate in the soil is 68.9%, 62.1%, 57.5%, and the removal efficiency of heavy metals in the solution is 67.46%. It can be concluded that when the soil is the cathode chamber. The removal rate of local heavy metals was the highest. When the solution was used as a cathode chamber, the average removal rate of heavy metals was the highest. The bacteria, named strain CD-1, as the electricity production bacteria (EPB) used in the dual chamber microbial fuel cell (MFC), was isolated from activate sludge and identified on its morphology, physichemical properties and phylogenetic positions. The results indicated that strain CD-1 was Gram-negative, rod. Oxidase and catalase reactions were positive. Strain CD-1 could use gluconate, lactose, D-fructose, L-Arabinose, D-arabinose, acetate, propionate, butyrate, lactate, sucrose and glucose, not use melibiose, galactose, N-acetylglucosamine, ethanol and glycerol.16S rRNA gene sequences analysis showed that strain CD-1 was most related to Ochrobactrum sp. (AJ245941）with the homology similarities of 98%. Based on the above results, strain CD-1 was belonged to the genus of Ochrobactrum and seemed to represent a novel species.</p>