Electricity Generation from Artificial Wastewater Using an Upflow Microbial Fuel Cell (original) (raw)
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The objective of this study was to evaluate the performance of an upflow membrane-less microbial fuel cell (UFML MFC) with various types of carbon material as cathodes in power output and chemical oxygen demand (COD) reduction. The UFML MFC was designed with carbon felt as anode material, and the bioreactor was filled with 0.6-cm diameter of gravel at the anode region. Carbon flake, Pt-loaded carbon paper, and carbon felt were used as cathode electrodes. The voltage output (power density) for the carbon flake cathode and Pt-loaded carbon paper cathode was 384± 16 mV (44.4±2.5 mW/m 2 ) and 399±9 mV (44.1± 3 mW/m 2 ), respectively. The percentage of COD reduction at the anode region and effluent was above 75 and 85 %, respectively, for all cathode materials. The coulombic efficiency was 15.95, 6.09, and 15.32 % for Ptloaded carbon paper, carbon felt, and carbon flake, respectively. The result suggests that power generation and COD reduction were influenced by the cathode material. Carbon flake can be considered as a costeffective cathode material in UFML MFC for future application in real biological wastewater treatment process.
Power generation in fed-batch and continuous up-flow microbial fuel cell from synthetic wastewater
Energy, 2015
Up-flow bioreactors have the advantages of retaining very high cell density and having high mass transfer efficiency. The recirculation rate could improve the up-flow rate in up-flow bioreactor. A twochamber UFMFC (up-flow microbial fuel cell) is constructed with flat graphite electrodes and anion exchange membrane for electricity generation. The anode chamber is seeded with compost culture enriched on xylose and operated on synthetic wastewater with 0.5 g/L xylose, external resistance of 100 U, at pH 7.0 and 37 C in fed-batch mode. The cathode chamber in the top of the UFMFC is filled with potassium ferricyanide (pH 7.0) as the electron acceptor. The effects of different recirculation rates of 1.2, 2.4, 4.8 and 7.2 RV (reactor-volumes)/h to increase the mass transfer and electricity production are determined in fed-batch mode. At a recirculation rate of 4.8 RV/h, a power density of 356 ± 24 mW/m 2 with CE (coulombic efficiency) of 21.3 ± 1.0% is obtained. Decreasing HRT (hydraulic retention time) could improve the electricity production performance of UFMFC in continuous mode. The power generation is increased to 372 ± 20 mW/m 2 , while CE remains at 13.4 ± 0.5% with HRT of 1.7 d and optimum recirculation rate of 4.8 RV/h on continuous mode. Microbial communities were characterized with PCR (polymerase chain reaction) e DGGE (denaturing gradient gel electrophoresis). In the end of the experiment, the biofilm contained both fermenting and exoelectrogenic bacteria, while fermenting and nitrate-reducing bacteria were mainly present in the anodic solutions. Moreover, some changes occurred in the microbial communities of the anodic solutions when the MFCs were switched from fed-batch to continuous mode, while the differences were minor between different recirculation rates in fed-batch mode.
The Scientific World Journal, 2013
Microbial fuel cells (MFCs) have the potential to simultaneously treat wastewater for reuse and to generate electricity. This study mainly considers the performance of an upflow dual-chambered MFC continuously fueled with actual domestic wastewater and alternatively biocatalyzed with aerobic activated sludge and strain ofBacillus Subtilis. The behavior of MFCs during initial biofilm growth and characterization of anodic biofilm were studied. After 45 days of continuous operation, the biofilms on the anodic electrode were well developed. The performance of MFCs was mainly evaluated in terms of COD reductions and electrical power output. Results revealed that the COD removal efficiency was 84% and 90% and the stabilized power outputs were clearly observed achieving a maximum value of 120 and 270 mW/m2obtained for MFCs inoculated with mixed cultures andBacillus Subtilisstrain, respectively.
Iranica Journal of Energy and Environment, 2013
A single chamber microbial fuel cell (SCMFC) was operated with distillery spent wash (DSW) wastewater and microorganisms in cow-dung as inoculum source from pH 4 to 9. MFC signifies maximum current in the sequence of pH 6 (0.46 mA) > pH 7 (0.4 mA) > pH 8-9 (0.16-0.19 mA); whereas the chemical oxygen demand (COD) removed in order of pH 8-9 (80-81%) > pH 7 (79%) > pH 6 (68%). The losses in coulombic yield were due to alternating electron acceptors and air diffusion through the reactor. The polarization curve yielded the maximum current density of 84 mA/m and maximum power density of 29 mW/m at an external resistance 2 2 of 820 (pH 6). The cyclic voltammetry (CV) demonstrated 3-electron transfer process with best electrochemical responses at pH 6 and 7. The MFC at desired operating conditions showed a positive response for bioelectricity generation.
Production of electricity during wastewater treatment using a single chamber microbial fuel cell
2004
Microbial fuel cells (MFCs) have been used to produce electricity from different compounds, including acetate, lactate, and glucose. We demonstrate here that it is also possible to produce electricity in a MFC from domestic wastewater, while at the same time accomplishing biological wastewater treatment (removal of chemical oxygen demand; COD). Tests were conducted using a single chamber microbial fuel cell (SCMFC) containing eight graphite electrodes (anodes) and a single air cathode. The system was operated under continuous flow conditions with primary clarifier effluent obtained from a local wastewater treatment plant. The prototype SCMFC reactor generated electrical power (maximum of 26 mW m -2 ) while removing up to 80% of the COD of the wastewater. Power output was proportional to the hydraulic retention time over a range of 3-33 h and to the influent wastewater strength over a range of 50-220 mg/L of COD. Current generation was controlled primarily by the efficiency of the cathode. Optimal cathode performance was obtained by allowing passive air flow rather than forced air flow (4.5-5.5 L/min). The Coulombic efficiency of the system, based on COD removal and current generation, was <12% indicating a substantial fraction of the organic matter was lost without current generation. Bioreactors based on power generation in MFCs may represent a completely new approach to wastewater treatment. If power generation in these systems can be increased, MFC technology may provide a new method to offset wastewater treatment plant operating costs, making advanced wastewater treatment more affordable for both developing and industrialized nations.
Potential Use of Microbial Fuel Cell Technology in Wastewater Treatment
Processes, 2022
Two options, in regard to applying microbial fuel cells (MFCs) in water treatment, are under discussion, namely the conversion of the chemical energy of organic substrates to electricity, as well as the use their potential to reduce different species, such as the ionic form of copper (Cu2+ converted to metal copper) and iron (Fe3+ converted to Fe2+). The high reduction potential of Cu2+ and Fe3+ makes the processes of electricity production and metal reduction, to be performed simultaneously in MFC, achievable. The electrical yield measurement during the experiments of anodic organic matter degradation by MFC in treating an artificial wastewater with chemical oxygen demand (COD) 0.6 and 1.6 g O2·dm−3, as initial COD, are given. It is demonstrated that the higher organic load is associated with better electrical yield. A comparison of MFC and conventional anaerobic digestion performance is discussed, as well. Experimental proofs of copper removal and phosphate mobilization, following...
Microbial Fuel Cells for Direct Electrical Energy Recovery from Urban Wastewaters
The Scientific World Journal, 2013
Application of microbial fuel cells (MFCs) to wastewater treatment for direct recovery of electric energy appears to provide a potentially attractive alternative to traditional treatment processes, in an optic of costs reduction, and tapping of sustainable energy sources that characterizes current trends in technology. This work focuses on a laboratory-scale, air-cathode, and single-chamber MFC, with internal volume of 6.9 L, operating in batch mode. The MFC was fed with different types of substrates. This study evaluates the MFC behaviour, in terms of organic matter removal efficiency, which reached 86% (on average) with a hydraulic retention time of 150 hours. The MFC produced an average power density of 13.2 mW/m3, with a Coulombic efficiency ranging from 0.8 to 1.9%. The amount of data collected allowed an accurate analysis of the repeatability of MFC electrochemical behaviour, with regards to both COD removal kinetics and electric energy production.
TREATMENT OF WASTEWATER AND ELECTRICITY GENERATION USING MICROBIAL FUEL CELL TECHNOLOGY
The need for alternate eco-friendly fuel is increasing rapidly with the depletion of non-renewable energy resources. Microbial fuel cells (MFCs) represent a new form of renewable energy, which converts organic matter into electricity with the help of bacteria present in wastewater, while simultaneously treating the wastewater. In the present study single chamber (MFC-1) and double chambered (MFC-2) MFCs were compared for domestic and dairy wastewater treatment and electricity generation. MFC-1 was proved to be more efficient and found to be producing maximum current of 0.84 mA and 1.02mA whereas MFC-2 produced maximum current of 0.56mA and 0.58mA from full strength (100%) domestic and dairy wastewater concentrations respectively. COD removal efficiency achieved in MFC-2 was 88.4% and 86.42% for 100% domestic and dairy wastewater concentrations respectively when compared with MFC-1 which attained 86.6% and 84.8% respectively for 100% domestic and dairy wastewater concentrations respectively. The performance of MFC-1 and MFC-2 decreased, when the wastewater concentration was decreased from 100% to 75% and 50% concentrations.