scholarly journals Electricity Generation in Microbial Fuel Cells Using Neutral Red as an Electronophore

2000 ◽  
Vol 66 (4) ◽  
pp. 1292-1297 ◽  
Author(s):  
Doo Hyun Park ◽  
J. Gregory Zeikus

ABSTRACT Neutral red (NR) was utilized as an electron mediator in microbial fuel cells consuming glucose to study both its efficiency during electricity generation and its role in altering anaerobic growth and metabolism of Escherichia coli andActinobacillus succinogenes. A study of chemical fuel cells in which NADH, NR, and ferricyanide were the electron donor, the electronophore, and the electron acceptor, respectively, showed that electrical current produced from NADH was proportional to the concentration of NADH. Fourfold more current was produced from NADH in chemical fuel cells when NR was the electron mediator than when thionin was the electron mediator. In microbial fuel cells in which E. coli resting cells were used the amount of current produced from glucose when NR was the electron mediator (3.5 mA) was 10-fold more than the amount produced when thionin was the electron mediator (0.4 mA). The amount of electrical energy generated (expressed in joules per mole of substrate) and the amount of current produced from glucose (expressed in milliamperes) in NR-mediated microbial fuel cells containing either E. coli or A. succinogeneswere about 10- and 2-fold greater, respectively, when resting cells were used than when growing cells were used. Cell growth was inhibited substantially when these microbial fuel cells were making current, and more oxidized end products were formed under these conditions. When sewage sludge (i.e., a mixed culture of anaerobic bacteria) was used in the fuel cell, stable (for 120 h) and equivalent levels of current were obtained with glucose, as observed in the pure-culture experiments. These results suggest that NR is better than other electron mediators used in microbial fuel cells and that sludge production can be decreased while electricity is produced in fuel cells. Our results are discussed in relation to factors that may improve the relatively low electrical efficiencies (1.2 kJ/mol) obtained with microbial fuel cells.

2008 ◽  
Vol 8 (8) ◽  
pp. 4132-4134 ◽  
Author(s):  
Tushar Sharma ◽  
A. Leela Mohana Reddy ◽  
T. S. Chandra ◽  
S. Ramaprabhu

Microbial Fuel Cells (MFC) are robust devices capable of taping biological energy, converting sugars into potential sources of energy. Persistent efforts are directed towards increasing power output. However, they have not been researched to the extent of making them competitive with chemical fuel cells. The power generated in a dual-chamber MFC using neutral red (NR) as the electron mediator has been previously shown to be 152.4 mW/m2 at 412.5 mA/m2 of current density. In the present work we show that Pt thin film coated carbon paper as electrodes increase the performance of a microbial fuel cell compared to conventionally employed electrodes. The results obtained using E. coli based microbial fuel cell with methylene blue and neutral red as the electron mediator, potassium ferricyanide in the cathode compartment were systematically studied and the results obtained with Pt thin film coated over carbon paper as electrodes were compared with that of graphite electrodes. Platinum coated carbon electrodes were found to be better over the previously used for microbial fuel cells and at the same time are cheaper than the preferred pure platinum electrodes.


2008 ◽  
Vol 136 ◽  
pp. S474-S475
Author(s):  
Yifeng Zhang ◽  
Liping Huang ◽  
Jingwen Chen ◽  
Xianliang Qiao ◽  
Xiyun Cai

2012 ◽  
Vol 66 (4) ◽  
pp. 748-753 ◽  
Author(s):  
Jaecheul Yu ◽  
Younghyun Park ◽  
Haein Cho ◽  
Jieun Chun ◽  
Jiyun Seon ◽  
...  

Microbial fuel cells (MFCs) can convert chemical energy to electricity using microbes as catalysts and a variety of organic wastewaters as substrates. However, electron loss occurs when fermentable substrates are used because fermentation bacteria and methanogens are involved in electron flow from the substrates to electricity. In this study, MFCs using glucose (G-MFC), propionate (P-MFC), butyrate (B-MFC), acetate (A-MFC), and a mix (M-MFC, glucose:propionate:butyrate:acetate = 1:1:1:1) were operated in batch mode. The metabolites and microbial communities were analyzed. The current was the largest electron sink in M-, G-, B-, and A-MFCs; the initial chemical oxygen demands (CODini) involved in current production were 60.1% for M-MFC, 52.7% for G-MFC, 56.1% for B-MFC, and 68.3% for A-MFC. Most of the glucose was converted to propionate (40.6% of CODini) and acetate (21.4% of CODini) through lactate (80.3% of CODini) and butyrate (6.1% of CODini). However, an unknown source (62.0% of CODini) and the current (34.5% of CODini) were the largest and second-largest electron sinks in P-MFC. Methane gas was only detected at levels of more than 10% in G- and M-MFCs, meaning that electrochemically active bacteria (EAB) could out-compete acetoclastic methanogens. The microbial communities were different for fermentable and non-fermentable substrate-fed MFCs. Probably, bacteria related to Lactococcus spp. found in G-MFCs with fermentable substrates would be involved in both fermentation and electricity generation. Acinetobacter-like species, and Rhodobacter-like species detected in all the MFCs would be involved in oxidation of organic compounds and electricity generation.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hsuanyi Huang ◽  
Rong Li ◽  
Cuixia Li ◽  
Feng Zheng ◽  
Giovanni A. Ramirez ◽  
...  

Abstract To drive the next ‘technical revolution’ towards commercialization, we must develop sustainable energy materials, procedures, and technologies. The demand for electrical energy is unlikely to diminish over the next 50 years, and how different countries engage in these challenges will shape future discourse. This perspective summarizes the technical aspects of nanomaterials’ design, evaluation, and uses. The applications include solid oxide fuel cells (SOFCs), solid oxide electrolysis cells (SOEC), microbial fuel cells (MFC), supercapacitors, and hydrogen evolution catalysts. This paper also described energy carriers such as ammonia which can be produced electrochemically using SOEC under ambient pressure and high temperature. The rise of electric vehicles has necessitated some form of onboard storage of fuel or charge. The fuels can be generated using an electrolyzer to convert water to hydrogen or nitrogen and steam to ammonia. The charge can be stored using a symmetrical supercapacitor composed of tertiary metal oxides with self-regulating properties to provide high energy and power density. A novel metal boride system was constructed to absorb microwave radiation under harsh conditions to enhance communication systems. These resources can lower the demand for petroleum carbon in portable power devices or replace higher fossil carbon in stationary power units. To improve the energy conversion and storage efficiency, we systematically optimized synthesis variables of nanomaterials using artificial neural network approaches. The structural characterization and electrochemical performance of the energy materials and devices provide guidelines to control new structures and related properties. Systemic study on energy materials and technology provides a feasible transition from traditional to sustainable energy platforms. This perspective mainly covers the area of green chemistry, evaluation, and applications of nanomaterials generated in our laboratory with brief literature comparison where appropriate. The conceptual and experimental innovations outlined in this perspective are neither complete nor authoritative but a snapshot of selecting technologies that can generate green power using nanomaterials.


Sign in / Sign up

Export Citation Format

Share Document