scholarly journals Microbial fuel cell power overshoot studied with microfluidics: from quantification to elimination

Author(s):  
Mehran Abbaszadeh Amirdehi ◽  
Lingling Gong ◽  
Nastaran Khodaparastasgarabad ◽  
Bruce E. Logan ◽  
Jesse Greener

Power overshoot can hinder determination of maximum power densities in microbial fuel cells (MFCs). In this work, a microfluidic approach was used to study overshoot in an MFC containing a pure culture of electroactive biofilms (EAB) containing Geobacter sulfurreducens. After 1-month operation under constant flow of an ideal nutrient medium, the MFC health began to degrade, marked by voltage loss and the appearance of anomalies in the power density curves. One such anomaly was a chronic power overshoot, accompanying a loss of both measured power and current density on the high-current side of the power density curve. The degree of power overshoot was quantified while certain flow-based interventions were applied, notably the shear erosion of the EAB outer layer. Next, two approaches to acclimation were demonstrated to treat the remaining overshoot. The standard approach, which acclimates the MFC to high currents before a standard polarization test, eliminated the remaining overshoot and returned maximum power densities to initial levels, but maximum current density remained lower than the initial level. A microfluidic-assisted “long-hold polarization test” enabled efficient in situ acclimation of each external resistor during the measurement. Despite the health-compromised MFC, this method provided long-term stability during the polarization test, resulting in power and current density measurements that exceeded those made on the healthy MFC using the standard polarization test. We conclude that slower electron transfer kinetics in unhealthy MFCs can provoke overshoot by prolonging the time to reach steady state during the polarization test, but a properly designed measurement overcomes this problem.

2015 ◽  
Vol 3 (2) ◽  
pp. 151-161
Author(s):  
A.N.Z. Alshehri

Microbial fuel cells (MFCs) are increasingly attracting attention as a sustainable technology as they convert chemical energy in organic pollutants to renewable electricity. Anthracene is a polycyclic aromatic hydrocarbon (PAH) that presents a high pollution and health risk. In this study, anthracene degradation with electricity production in Single – chamber air cathode MFC was investigated with respect to values of its biodegradation and MFC performance using different inocula combinations (Anaerobic sludge (AS), Pseudomonas putida (PP), Geobacter sulfurreducens (GS), Shewanella putrefaciens(SP), mixed cultures, and combinations thereof). All the inocula showed high potentials for anthracene degradation efficiency and power density, ranged 41 – 98 % within 120 – 216h and 110.08 – 156.06 mW/m2, respectively. The best overall performing inoculum was anaerobic sludge supplemented with P. putida (AS+PP), having a degradation rate, degradation efficiency, COD removal, maximum power density and coulombic efficiency of 38 μM/d, 98 %, 83 %, 156.06 mW/m2 and 21, respectively. Effect of initial anthracene concentration was also investigated. Results indicated that increasing of initial anthracene concentration to 40 mg/L has a positive effect on both the anthracene degradation rate and the power density by 79 and 83.93 %, respectively, which attained by the best inoculum AS+PP (degradation rate of 41 μM/d and a maximum power density of 287.04 mW/m2).This study highlights the possibility of using MFCs technology to generate renewable electricity and achieve high degradation rates of anthracene simultaneously, through co-metabolism.Int J Appl Sci Biotechnol, Vol 3(2): 151-161 DOI: http://dx.doi.org/10.3126/ijasbt.v3i2.12731 


2018 ◽  
Vol 8 (12) ◽  
pp. 2504
Author(s):  
Junxian Shi ◽  
Anhuai Lu ◽  
Haibin Chu ◽  
Hongyu Wu ◽  
Hongrui Ding

Developing simple and cheap electrocatalysts or photocatalysts for cathodes to increase the oxygen reduction process is a key factor for better utilization of microbial fuel cells (MFCs). Here, we report the investigation of natural wolframite employed as a low-cost cathode photocatalyst to improve the performance of MFCs. The semiconducting wolframite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The band gap and photo respond activities were determined by UV-vis spectroscopy and linear sweep voltammetry (LSV), respectively. Compared with the normal graphite cathode, when MFCs were equipped with a wolframite-coated cathode, the maximum power density was increased from 41.47 mW·m−2 to 95.51 mW·m−2. Notably, the maximum power density further improved to 135.57 mW·m−2 under light irradiation, which was 2.4 times higher than with a graphite cathode. Our research demonstrated that natural wolframite, a low-cost and abundant natural semiconducting mineral, showed promise as an effective photocathode catalyst which has great potential applications related to utilizing natural minerals in MFCs and for environmental remediation by MFCs in the future.


REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 52-58
Author(s):  
Marcelinus Christwardana ◽  
Linda Aliffia Yoshi ◽  
J. Joelianingsih

This study demonstrates the feasibility of producing bioelectricity utilizing yeast microbial fuel cell (MFC) technology with sugarcane bagasse juice as a substrate. Yeast Saccharomyces cerevisiae was employed as a bio-catalyst in the production of electrical energy. Sugarcane bagasse juice can be used as a substrate in MFC yeast because of its relatively high sugar content. When yeast was used as a biocatalyst, and Yeast Extract, Peptone, D-Glucose (YPD) Medium was used as a substrate in the MFC in the acclimatization process, current density increased over time to reach 171.43 mA/m2 in closed circuit voltage (CCV), maximum power density (MPD) reached 13.38 mW/m2 after 21 days of the acclimatization process. When using sugarcane bagasse juice as a substrate, MPD reached 6.44 mW/m2 with a sugar concentration of about 5230 ppm. Whereas the sensitivity, maximum current density (Jmax), and apparent Michaelis-Menten constant (𝐾𝑚𝑎𝑝𝑝) from the Michaelis-Menten plot were 0.01474 mA/(m2.ppm), 263.76 mA/m2, and 13594 ppm, respectively. These results indicate that bioelectricity can be produced from sugarcane bagasse juice by Saccharomyces cerevisiae.Keywords: biomass valorization, biofuel cell, acclimatization, maximum power density, Michaelis-Menten constant


2019 ◽  
Vol 43 (24) ◽  
pp. 9389-9395 ◽  
Author(s):  
Cuie Zhao ◽  
Jinxiang Li ◽  
Yan Chen ◽  
Jianyu Chen

In this study, nitrogen- and sulfur-codoped graphene (N/S-G) was prepared and used as an efficient metal-free electrocatalyst for the oxygen reduction reaction (ORR) in microbial fuel cells (MFCs), exhibiting a maximum power density of 1368 mW m−2, relatively higher than that of commercial Pt/C.


2005 ◽  
Vol 2 (4) ◽  
pp. 234-237 ◽  
Author(s):  
A. Verma ◽  
A. K. Jha ◽  
S. Basu

The performance of an alkaline fuel cell (AFC) is investigated using three different fuels, e.g., methanol, ethanol, and sodium borohydride. Pt∕C∕Ni was used as anode, whereas MnO2∕C∕Ni was used as standard (Electro-Chem-Technic, UK) cathode for all the fuels. Fresh mixture of electrolyte, potassium hydroxide (5M), and fuel (2M) was fed to AFC and withdrawn at a rate of 1ml∕min. The anode was prepared by dispersing platinum and activated carbon in Nafion® (DuPont USA) dispersion and placing it onto a carbon paper (Lydall, USA). Finally prepared anode material was pressed onto Ni mesh and sintered to produce the required anode. The maximum power density of 16.5mW∕cm2 is obtained at 28mA∕cm2 of current density for sodium borohydride at 25°C, whereas methanol produces 31.5mW∕cm2 of maximum power density at 44mA∕cm2 of current density at 60°C. The results obtained showed that the AFC could accept multifuels.


2017 ◽  
Vol 76 (3) ◽  
pp. 683-693 ◽  
Author(s):  
Edson Baltazar Estrada-Arriaga ◽  
Yvonne Guillen-Alonso ◽  
Cornelio Morales-Morales ◽  
Liliana García-Sánchez ◽  
Erick Obed Bahena-Bahena ◽  
...  

Two different air-cathode stacked microbial fuel cell (MFC) configurations were evaluated under continuous flow during the treatment of municipal wastewater and electricity production at a hydraulic retention time (HRT) of 3, 1, and 0.5 d. Stacked MFC 1 was formed by 20 individual air-cathode MFC units. The second stacked MFC (stacked MFC 2) consisted of 40 air-cathode MFC units placed in a shared reactor. The maximum voltages produced at closed circuit (1,000 Ω) were 170 mV for stacked MFC 1 and 94 mV for stacked MFC 2. Different power densities in each MFC unit were obtained due to a potential drop phenomenon and to a change in chemical oxygen demand (COD) concentrations inside reactors. The maximum power densities from individual MFC units were up to 1,107 mW/m2 for stacked MFC 1 and up to 472 mW/m2 for stacked MFC 2. The maximum power densities in stacked MFC 1 and MFC 2 connected in series were 79 mW/m2 and 4 mW/m2, respectively. Electricity generation and COD removal efficiencies were reduced when the HRT was decreased. High removal efficiencies of 84% of COD, 47% of total nitrogen, and 30% of total phosphorus were obtained during municipal wastewater treatment.


2020 ◽  
Vol 49 (12) ◽  
pp. 3229-3241
Author(s):  
Aisyah Nadhirah Juhari ◽  
Muhd Syazwan Sharani ◽  
Wan Ramli Wan Daud ◽  
Tahereh Jafary ◽  
Mimi Hani Abu Bakar

A biophotovoltaic cell (BPV) is an electrobiochemical system that utilises a photosynthetic microorganism for instance is algae to trap sunlight energy and convert it into electricity. In this study, a local algae strain, UKM2 Chlorella sp. was grown in a BPV under different trophic conditions and light wavelengths. Once the acclimatisation phase succeeded, and biofilm formed, power generation by UKM2 algae at the autotrophic mode in synthetic Bold’s Basal media (BBM) under white, blue and red lights were tested. Polarisation and power curves were generated at these different conditions to study the bioelectrochemical performance of the system. Later, the condition switched to algal mixotrophic nutritional mode, with palm oil mill effluent (POME) as substrate. Maximum power generation obtained when using UKM2 in BBM under red light where a power density of 1.19 ± 0.16 W/m3 was obtained at 25.74 ± 3.89 A/m3 current density, while the open circuit voltage OCV reached 226.08 ± 8.71 mV. UKM2 in POME under blue light recorded maximum power density of 0.85 ± 0.18 W/m3 at current density of 16.75 ± 3.54 A/m3, while the OCV reached 214.05 ± 23.82 mV. Chemical oxygen demand (COD) removal reached an efficiency of 35.93%, indicating the ability of wastewater treatment and electricity generation in BPV at the same time.


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2194
Author(s):  
Chikashi Sato ◽  
N. Evelin Paucar ◽  
Steve Chiu ◽  
Muhammad Z. I. M. Mahmud ◽  
John Dudgeon

In this study, three single-chamber microbial fuel cells (MFCs), each having Pt-coated carbon cloth as a cathode and four bamboo charcoal (BC) plates as an anode, were run in a fed-batch mode, individually and in series. Simulated potato-processing wastewater was used as a substrate for supporting the growth of a mixed bacterial culture. The maximum power output increased from 0.386 mW with one MFC to 1.047 mW with three MFCs connected in series. The maximum power density, however, decreased from 576 mW/m2 (normalized to the cathode area) with one MFC to 520 mW/m2 with three MFCs in series. The experimental results showed that power can be increased by connecting the MFCs in series; however, choosing low resistance BC is crucial for increasing power density.


Author(s):  
A. Verma ◽  
A. K. Jha ◽  
S. Basu

The performance of an alkaline fuel cell is investigated using three different fuels, e g., methanol, ethanol and sodium borohydride. Pt/C/Ni was used as anode whereas Mn/C/Ni was used as standard (Electro-Chem-Technic, UK) cathode for all the fuels. Thus, the alkaline fuel cell is used for multi-fuel system. Fresh mixture of electrolyte, potassium hydroxide (5M), and fuel (2M) was fed to and withdrawn from the AFC at a rate of 1 ml/min. The anode was prepared by dispersing platinum and activated carbon in Nafion® (DuPont USA) dispersion and placing it onto a carbon paper (Lydall, USA). Finally prepared anode sheet was pressed onto Ni mesh and sintered to produce the required anode. The maximum power density of 16.5 mW/cm2 is obtained at 28 mA/cm2 of current density for sodium borohydride at 25 °C. Whereas, methanol produces 31.5 mW/cm2 of maximum power density at 44 mA/cm2 of current density at 60 °C.


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