Energy generation in a novel microbial fuel cell: characterization and dynamics of microbial communities using organic matter and ammonia as electron donors

ABSTRACT The ability of Pelobacter carbinolicus to oxidize electron donors with electron transfer to the anodes of microbial fuel cells was evaluated because microorganisms closely related to Pelobacter species are generally abundant on the anodes of microbial fuel cells harvesting electricity from aquatic sediments. P. carbinolicus could not produce current in a microbial fuel cell with electron donors which support Fe(III) oxide reduction by this organism. Current was produced using a coculture of P. carbinolicus and Geobacter sulfurreducens with ethanol as the fuel. Ethanol consumption was associated with the transitory accumulation of acetate and hydrogen. G. sulfurreducens alone could not metabolize ethanol, suggesting that P. carbinolicus grew in the fuel cell by converting ethanol to hydrogen and acetate, which G. sulfurreducens oxidized with electron transfer to the anode. Up to 83% of the electrons available in ethanol were recovered as electricity and in the metabolic intermediate acetate. Hydrogen consumption by G. sulfurreducens was important for ethanol metabolism by P. carbinolicus. Confocal microscopy and analysis of 16S rRNA genes revealed that half of the cells growing on the anode surface were P. carbinolicus, but there was a nearly equal number of planktonic cells of P. carbinolicus. In contrast, G. sulfurreducens was primarily attached to the anode. P. carbinolicus represents the first Fe(III) oxide-reducing microorganism found to be unable to produce current in a microbial fuel cell, providing the first suggestion that the mechanisms for extracellular electron transfer to Fe(III) oxides and fuel cell anodes may be different.

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Effect of Different Mediators on Bio-Energy Generation and Palm Oil Mill Effluent Treatment in an Air-Cathode Microbial Fuel Cell-Adsorption System

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.411.67 ◽

2021 ◽

Vol 411 ◽

pp. 67-78

Author(s):

Ivy Ai Wei Tan ◽

J.R. Selvanathan ◽

M.O. Abdullah ◽

N. Abdul Wahab ◽

D. Kanakaraju

Keyword(s):

Fuel Cell ◽

Microbial Fuel Cell ◽

Palm Oil ◽

Oxygen Demand ◽

Energy Generation ◽

Effluent Treatment ◽

Palm Oil Mill Effluent ◽

Adsorption System ◽

Air Cathode ◽

Palm Oil Mill

Palm oil mill effluent (POME) discharged without treatment into watercourses can pollute the water source. Microbial fuel cell (MFC) has gained high attention as a green technology of converting organic wastewater into bio-energy. As an approach to overcome the limitations of the existing POME treatment methods, air-cathode MFC-Adsorption system is introduced as an innovative technology to treat POME and generate bio-electricity simultaneously. However, the use of conventional MFC with proton exchange membrane in large scale applications is restricted by the high cost and low power generation. Addition of mediator in MFC is essential in order to increase the electron transfer efficiency, hence enhancing the system performance. This study therefore aims to investigate the effect of different type of mediators i.e. congo red (CR), crystal violet (CV) and methylene blue (MB) on the performance of an affordable air-cathode MFC-Adsorption system made from earthen pot with POME as the substrate. The addition of different mediators altered the pH of the MFC-Adsorption system, in which more alkaline system showed better performance. The voltage generated in the system with CR, CV and MB mediator was 120.58 mV, 168.63 mV and 189.25 mV whereas the current generated was 2.41 mA, 3.37 mA and 3.79 mA, respectively. The power density of 290.79 mW/m3, 568.72 mW/m3 and 716.31 mW/m3 was produced in the MFC-Adsorption system with CR, CV and MB mediator, respectively. The highest POME treatment efficiency was achieved in MFC-Adsorption system with MB mediator, which resulted in biochemical oxygen demand, chemical oxygen demand, total suspended solids, turbidity and ammoniacal nitrogen removal of 75.3%, 84.8%, 91.5%, 86.1% and 23.31%, respectively. Overall, the air-cathode MFC-Adsorption system with addition of MB mediator was feasible for POME treatment and simultaneous bio-energy generation.

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EXPERIMENTAL STUDY OF BIOELECTRICITY-MICROBIAL FUEL CELL FOR ELECTRICITY GENERATION: PERFORMANCE CHARACTERIZATION AND CAPACITY IMPROVEMENT

Jurnal Teknologi ◽

10.11113/jt.v79.11271 ◽

2017 ◽

Vol 79 (5-2) ◽

Author(s):

Zul Hasrizal Bohari ◽

Nur Asyhikin Azhari ◽

Nuraina Nasuha Ab Rahman ◽

Mohamad Faizal Baharom ◽

Mohd Hafiz Jali ◽

...

Keyword(s):

Organic Matter ◽

Fuel Cell ◽

Microbial Fuel Cell ◽

Electrical Power ◽

Electrical Energy ◽

Sewage Water ◽

Electricity Production ◽

Sample Type ◽

Series Of Experiments ◽

The Right

Energy trending lately shown the need of new possible renewable energy. This paper studies about the capability and capacity generating of electricity by using Bio-electricity-Microbial Fuel Cell (Bio-MFC). Bio-MFC is the device that converts chemical energy to electrical energy by using microbes that exist in the sewage water. The energy contained in organic matter can be converted into useful electrical power. MFC can be operated by microbes that transfer electrons from anode to cathode for generating electricity. There are two major goals in this study. The first goal is to determine the performance characteristics of MFCs in this application. Specifically we investigate the relationship between the percentages of organic matter in a sample results in higher electricity production of MFCs power by that sample. As a result, the sewage (wastewater) chosen in the second series experiment because the sewage (wastewater) also produced the highest percentage of organic matter which is around 10%. Due to these, the higher percentage of organic matter corresponds to higher electricity production. The second goal is to determine the condition under which MFC work most efficiently to generating electricity. After get the best result of the combination for the electrode, which is combination of zinc and copper (900mV),the third series of experiments was coducted, that show the independent variable was in the ambient temperature. The reasons of these observations will be explained throughout the paper. The study proved that the electricity production of MFC can be increased by selecting the right condition of sample type, temperature and type of electrode.

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