共查询到20条相似文献,搜索用时 15 毫秒
1.
Tian-shun Song Xia-yuan Wu Charles C. Zhou 《Bioprocess and biosystems engineering》2014,37(2):133-138
Single-chamber microbial fuel cells (MFCs) with air-cathode were constructed. MFCs were fed different feedstocks during their inoculation, their role on phenol degradation and MFC performance were investigated. The results showed that the MFC inoculated using glucose exhibited the highest power density (31.3 mW m?2) when phenol was used as the sole substrate for MFC. The corresponding biodegradation kinetic constant was obtained at 0.035 h?1, at an initial phenol concentration of 600 mg L?1. Moreover, the phenol degradation rates in this MFC with closed circuit were 9.8–16.5 % higher than those in MFC with opened circuit. The cyclic voltammograms revealed a different electrochemical activity of the anode biofilms in the MFC, and this led to differences in performance of the MFCs with phenol as sole substrate. These results demonstrated that phenol degradation and power production are affected by current generation and type of acclimation. 相似文献
2.
《Process Biochemistry》2010,45(6):929-934
The aim of this study is to compare the performance of different membrane cathode assembly (MCA) and cloth-cathode assembly (CCA) in air-chamber microbial fuel cells (MFCs) and provide an optimum cathode configuration for MFC scaling up. Two MCAs were prepared by hot-pressing carbon cloth containing cathodic catalyst to anion exchange membrane (AEM) and cation exchange membrane (CEM), respectively. A CCA was built by coating GORE-TEX® cloth with a mixture of nickel-based conductive paint and cathodic catalyst. Under the fed-batch mode using brewery wastewater, the MFCs were compared with respect to power production, coulombic efficiency, COD removal, internal resistance and material cost. The experimental results show that CCA is a more favorable alternative than MCAs due to its easier preparation, higher maximum power density and COD removal, and lower internal resistance and cost. The optimum cathode assembly of CCA is cost-effective and mechanically robust enough to meet the important requirements for MFC scalability. 相似文献
3.
This paper reports a novel configuration of stacked microbial fuel cells (MFCs) bridged internally through an extra cation
exchange membrane (CEM). The MFC stack (MFCstack), assembled from two single MFCs (MFCsingle), resulted in double voltage output and half optimal external resistance. COD removal rate was increased from 32.4% to 54.5%.
The performance improvement could be attributed to the smaller internal resistance and enhanced cations transfer. A result
from a half cell study further confirmed the important role of the extra CEM. This study also demonstrated MFCs where the
anode and cathode were sandwiched between two CEMs possessed significantly high power outputs 相似文献
4.
Jonathan Winfield John Greenman David Huson Ioannis Ieropoulos 《Bioprocess and biosystems engineering》2013,36(12):1913-1921
The properties of earthenware and terracotta were investigated in terms of structural integrity and ion conductivity, in two microbial fuel cell (MFC) designs. Parameters such as wall thickness (4, 8, 18 mm), porosity and cathode hydration were analysed. During the early stages of operation (2 weeks), the more porous earthenware lost anolyte quickly and was unstable between feeding compared to terracotta. Three weeks later MFCs of all thicknesses were more stable and could sustain longer periods of power production without maintenance. In all cases, the denser terracotta produced higher open circuit voltage; however, earthenware the more porous and less iron-rich of the two, proved to be the better material for power production, to the extent that the thickest wall (18 mm) MFC produced 15 % higher power than the thinnest wall (4 mm) terracotta. After 6 weeks of operation, the influence of wall thickness was less exaggerated and power output was comparable between the 4 and 8 mm ceramic membranes. Cylindrical earthenware MFCs produced significantly higher current (75 %) and power (33 %) than terracotta MFCs. A continuous dripping mode of cathode hydration produced threefold higher power than when MFCs were submerged in water, perhaps because of a short-circuiting effect through the material. This shows a significant improvement in terms of biosystems engineering, since a previously high-maintenance half-cell, is now shown to be virtually self-sufficient. 相似文献
5.
Flexible and Stretchable Biobatteries: Monolithic Integration of Membrane‐Free Microbial Fuel Cells in a Single Textile Layer
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The fabrication and performance of a flexible and stretchable microbial fuel cell (MFC) monolithically integrated into a single sheet of textile substrate are reported. The single‐layer textile MFC uses Pseudomonas aeruginosa (PAO1) as a biocatalyst to produce a maximum power of 6.4 µW cm?2 and current density of 52 µA cm?2, which are substantially higher than previous textile‐MFCs and are similar to other flexible paper‐based MFCs. The textile MFC demonstrates a stable performance with repeated stretching and twisting cycles. The membrane‐less single‐chamber configuration drastically simplifies the fabrication and improves the performance of the MFC. A conductive and hydrophilic anode in a 3D fabric microchamber maximizes bacterial electricity generation from a liquid environment and a silver oxide/silver solid‐state cathode reduces cathodic overpotential for fast catalytic reaction. A simple batch fabrication approach simultaneously constructs 35 individual devices, which will revolutionize the mass production of textile MFCs. This stretchable and twistable power device printed directly onto a single textile substrate can establish a standardized platform for textile‐based biobatteries and will be potentially integrated into wearable electronics in the future. 相似文献
6.
Microbial fuel cells (MFCs) are a technology that provides electrical energy from the microbial oxidation of organic compounds. Most MFCs use oxygen as the oxidant in the cathode chamber. This study examined the formation in culture of an unidentified bacterial oxidant and investigated the performance of this oxidant in a two-chambered MFC with a proton exchange membrane and an uncoated carbon cathode. DNA, FAME profile and characterization studies identified the microorganism that produced the oxidant as Burkholderia cenocepacia. The oxidant was produced by log phase cells, oxidized the dye 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), had a mass below 1 kD, was heat stable (121°C) and was soluble in ethanol. In a MFC with a 1000 Ω load and ABTS as a mediator, the oxidizer increased cell voltage 11 times higher than atmospheric oxygen and 2.9 times higher than that observed with ferricyanide in the cathode chamber. No increase in cell voltage was observed when no mediator was present. Organisms that produce and release oxidizers into the media may prove useful as bio-cathodes by improving the electrical output of MFCs. 相似文献
7.
Libin Zhang Jinyou Shen Lianjun Wang Lili Ding Ke Xu Hongqiang Ren 《Bioprocess and biosystems engineering》2014,37(5):819-827
Performances of microbial fuel cells (MFCs) were studied at 5–10 and 25–30 °C. Results showed stable operation of the MFCs at low temperatures with only slight reductions of voltage and power generation (11 versus 14 % for double-chamber MFC, while 14 versus 21 % for single-chamber MFC, 1,000 Ω) compared to those at mesophilic temperatures. MFCs operated at low temperatures showed lower COD removal rates accompanied by higher coulombic efficiencies (CEs). PCR-DGGE analysis revealed that psychrotrophic microbes (mainly Arcobacter, Pseudomonas, and Geobacter) dominated on anodes of the MFCs at low temperatures. Interestingly, light-induced red substances appeared on anode of the MFCs operated at low temperature and were proven to be the main anodic microbes (Arcobacter and Pseudomonas). Co-existence of the aforementioned microbes could assist stable low-temperature operation of the MFCs. Cyclic voltammetry analysis supported the results of the CE and DGGE. Stable performance of MFCs at low temperatures might be achieved by the control of anodic bacteria. 相似文献
8.
Wei Guo Yanrui Cui Hong Song Jianhui Sun 《Bioprocess and biosystems engineering》2014,37(9):1749-1758
Development of highly efficient anode is critical for enhancing the power output of microbial fuel cells (MFCs). The aim of this work is to investigate whether modification of carbon paper (CP) anode with graphene (GR) via layer-by-layer assembly technique is an effective approach to promote the electricity generation and methyl orange removal in MFCs. Using cyclic voltammetry and electrochemical impedance spectroscopy, the GR/CP electrode exhibited better electrochemical behavior. Scanning electron microscopy results revealed that the surface roughness of GR/CP increased, which was favorable for more bacteria to attach to the anode surface. The MFCs equipped with GR/CP anode achieved a stable maximum power density of 368 mW m?2 under 1,000 Ω external resistance and a start time for the initial maximum voltage of 180 h, which were, respectively, 51 % higher and 31 % shorter than the corresponding values of the MFCs with blank anode. The anode and cathode polarization curves revealed negligible difference in cathode potentials but obviously difference in anode potentials, indicating that the GR-modified anode other than the cathode was responsible for the performance improvement of MFC. Meanwhile, compared with MFCs with blank anode, 11 % higher decolorization efficiency and 16 % higher the chemical oxygen demand removal rate were achieved in MFC with GR-modified anode during electricity generation. This study might provide an effective way to modify the anode for enhanced electricity generation and efficient removal of azo dye in MFCs. 相似文献
9.
Amor Larrosa-Guerrero Keith Scott Krishna P. Katuri Carlos Godinez Ian M. Head Thomas Curtis 《Applied microbiology and biotechnology》2010,87(5):1699-1713
The influence of various carbon anodes; graphite, sponge, paper, cloth, felt, fiber, foam and reticulated vitreous carbon (RVC); on microbial fuel cell (MFC) performance is reported. The feed was brewery wastewater diluted in domestic wastewater. Biofilms were grown at open circuit or under an external load. Microbial diversity was analysed as a function of current and anode material. The bacterial community formed at open circuit was influenced by the anode material. However at closed circuit its role in determining the bacterial consortia formed was less important than the passage of current. The rate and extent of organic matter removal were similar for all materials: over 95% under closed circuit. The biofilm in MFCs working at open circuit and in the control reactors, increased COD removal by up to a factor of nine compared with that for baseline reactors. The average voltage output was 0.6 V at closed circuit, with an external resistor of 300 kΩ and 0.75 V at open circuit for all materials except RVC. The poor performance of this material might be related to the surface area available and concentration polarizations caused by the morphology of the material and the structure of the biofilm. Peak power varied from 1.3 mW m?2 for RVC to 568 mW m?2 for graphite with biofilm grown at closed circuit. 相似文献
10.
Raw primary sludge and the prefermentation liquor (PL) of primary sludge were used to generate electricity in single-chambered air-cathode microbial fuel cells (MFCs). The MFCs treating the primary sludge produced 0.53 V and 370 mW/m2 for the maximum potential and power density, respectively. In the primary sludge-fed MFCs, only 5 % of the total energy production was produced from direct electricity generation, whereas 95 % of that resulted from the conversion of methane to electricity. MFCs treating the PL generated the maximum potential of 0.58 V and maximum power density of 885 mW/m2, respectively. In the energy production analysis, direct electricity production (1,921 Wh/kg TCODrem) in the MFCs treating the PL was much higher than that of the primary sludge-fed MFC (138 Wh/kg TCODrem). Volatile suspended solids during 10 days were reduced to 18.3 and 38 % in the primary sludge-fed MFCs and prefermentation reactor, respectively. These findings suggest that a two-stage process including prefermentation and MFCs is of great benefit on sludge reduction and higher electricity generation from primary sludge. 相似文献
11.
Increased power generation from primary sludge by a submersible microbial fuel cell and optimum operational conditions 总被引:1,自引:0,他引:1
Valentina Vologni Ramesh Kakarla Irini Angelidaki Booki Min 《Bioprocess and biosystems engineering》2013,36(5):635-642
Microbial fuel cells (MFCs) have received attention as a promising renewable energy technology for waste treatment and energy recovery. We tested a submersible MFC with an innovative design capable of generating a stable voltage of 0.250 ± 0.008 V (with a fixed 470 Ω resistor) directly from primary sludge. In a polarization test, the maximum power density was 0.18 W/m2 at a current density of 0.8 A/m2 with an external resistor of 300 Ω. The anodic solution of the primary sludge needs to be adjusted to a pH 7 for high power generation. The modified primary sludge with an added phosphate buffer prolonged the current generation and increased the power density by 7 and 1.5 times, respectively, in comparison with raw primary sludge. These findings suggest that energy recovery from primary sludge can be maximized using an advanced MFC system with optimum conditions. 相似文献
12.
Gábor Márk Tardy Bálint Lóránt Máté Lóka Balázs Nagy Krisztina László 《Biotechnology letters》2017,39(7):993-999
Objectives
Catalytic efficiency of a nitrogen-doped, mesoporous carbon aerogel cathode catalyst was investigated in a two-chambered microbial fuel cell (MFC) applying graphite felt as base material for cathode and anode, utilizing peptone as carbon source.Results
This mesoporous carbon aerogel containing catalyst layer on the cathode increased the maximum power density normalized to the anode volume to 2.7 times higher compared to the maximum power density obtained applying graphite felt cathode without the catalyst layer. At high (2 and 3) cathode/anode volume ratios, maximum power density exceeded 40 W m?3. At the same time, current density and specific substrate utilization rate increased by 58% resulting in 31.9 A m?3 and 18.8 g COD m?3 h?1, respectively (normalized to anode volume). Besides the increase of the power and the rate of biodegradation, the investigated catalyst decreased the internal resistance from the range of 450–600 to 350–370 Ω.Conclusions
Although Pt/C catalyst proved to be more efficient, a considerable decrease in the material costs might be achieved by substituting it with nitrogen-doped carbon aerogel in MFCs. Such cathode still displays enhanced catalytic effect.13.
Recent advances in the separators for microbial fuel cells 总被引:2,自引:0,他引:2
Separator plays an important role in microbial fuel cells (MFCs). Despite of the rapid development of separators in recent years, there are remaining barriers such as proton transfer limitation and oxygen leakage, which increase the internal resistance and decrease the MFC performance, and thus limit the practical application of MFCs. In this review, various separator materials, including cation exchange membrane, anion exchange membrane, bipolar membrane, microfiltration membrane, ultrafiltration membranes, porous fabrics, glass fibers, J-Cloth and salt bridge, are systematically compared. In addition, recent progresses in separator configuration, especially the development of separator electrode assemblies, are summarized. The advances in separator materials and configurations have opened up new promises to overcome these limitations, but challenges remain for the practical application. Here, an outlook for future development and scaling-up of MFC separators is presented and some suggestions are highlighted. 相似文献
14.
Ola M. Gomaa Segun Fapetu Godfrey Kyazze Tajalli Keshavarz 《World journal of microbiology & biotechnology》2017,33(3):56
Dissimilatory metal reducing bacteria can exchange electrons extracellularly and hold great promise for their use in simultaneous wastewater treatment and electricity production. This study investigated the role of riboflavin, an electron carrier, in the decolourisation of Congo red in microbial fuel cells (MFCs) using Shewanella oneidensis MR-1 as a model organism. The contribution of the membrane-bound protein MtrC to the decolourisation process was also investigated. Within the range of riboflavin concentrations tested, 20 µM was found to be the best with >95% of the dye (initial concentration 200 mg/L) decolourised in MFCs within 50 h compared to 90% in the case where no riboflavin was added. The corresponding maximum power density was 45 mW/m2. There was no significant difference in the overall decolourisation efficiencies of Shewanela oneidensis MR-1 ΔMtrC mutants compared to the wild type. However, in terms of power production the mutant produced more power (Pmax 76 mW/m2) compared to the wild type (Pmax 46 mW/m2) which was attributed to higher levels of riboflavin secreted in solution. Decolourisation efficiencies in non-MFC systems (anaerobic bottles) were similar to those under MFC systems indicating that electricity generation in MFCs does not impair dye decolourisation efficiencies. The results suggest that riboflavin enhances both decolourisation of dyes and simultaneous electricity production in MFCs. 相似文献
15.
Treatment of domestic wastewater using microbial fuel cells (MFCs) will require reactors with multiple electrodes, but this presents unique challenges under continuous flow conditions due to large changes in the chemical oxygen demand (COD) concentration within the reactor. Domestic wastewater treatment was examined using a single-chamber MFC (130 mL) with multiple graphite fiber brush anodes wired together and a single air cathode (cathode specific area of 27 m2/m3). In fed-batch operation, where the COD concentration was spatially uniform in the reactor but changed over time, the maximum current density was 148?±?8 mA/m2 (1,000 Ω), the maximum power density was 120 mW/m2, and the overall COD removal was >90 %. However, in continuous flow operation (8 h hydraulic retention time, HRT), there was a 57 % change in the COD concentration across the reactor (influent versus effluent) and the current density was only 20?±?13 mA/m2. Two approaches were used to increase performance under continuous flow conditions. First, the anodes were separately wired to the cathode, which increased the current density to 55?±?15 mA/m2. Second, two MFCs were hydraulically connected in series (each with half the original HRT) to avoid large changes in COD among the anodes in the same reactor. The second approach improved current density to 73?±?13 mA/m2. These results show that current generation from wastewaters in MFCs with multiple anodes, under continuous flow conditions, can be improved using multiple reactors in series, as this minimizes changes in COD in each reactor. 相似文献
16.
Oxygen availability is a potential rate-limiting step in the bioelectrochemical process catalyzed by microbes in microbial fuel cells (MFC). Determination of oxygen availability using a minimally invasive oxygen sensor is advantageous in terms of ease of usage, maintenance and cost-effectiveness as compared to using conventional probe-type oxygen sensors. The utility of this method is substantiated by using this sensor to demonstrate the relationship between oxygen availability and current density. 10 % drop in oxygen concentration resulted in a concomitant drop in current density by about 36 %, further establishing the criticality of monitoring oxygen levels in the MFC. The detachable sensor membrane of the minimally invasive sensor confers multiple advantages. The novel method would enable real-time monitoring of oxygen in MFCs, simplify process optimization and validation and more importantly, provide an impetus for development of more efficient MFC designs. 相似文献
17.
The purpose of this study was to determine the effect of enrichment procedure on the performance and microbial diversity of
an air-cathode microbial fuel cell (MFC) which was explored for simultaneous azo dye decolorization and electricity generation.
Two different enrichment procedures in which glucose and Congo red were added into the MFCs sequentially (EP1) or simultaneously
(EP2) were tested by operating parallel MFCs independently for more than 6 months. The power density, electrode potential,
Congo red decolorization, biofilm morphology, and bacterial diversity of the MFCs under the two enrichment procedures were
compared and investigated. The results showed that the enrichment procedures have a negligible effect on the dye decolorization,
but significantly affected the electricity generation. More than 90% decolorization at dye concentration of 300 mg/L was achieved
within 170 h for the two tested enrichment procedures. However, the MFC with EP2 achieved a maximum power density of 192 mW/m2, which was 75% higher than that of the MFC with EP1 (110 mW/m2). The depressed surfaces of the bacteria in the MFC with EP1 indicated the allergic response caused by the subsequent addition
of Congo red. 16S rRNA sequencing analysis demonstrated a phylogenetic diversity in the communities of the anode biofilm and
showed clear differences between the anode-attached populations in the MFCs with a different enrichment procedure. This study
suggests that the enrichment procedure is important for the MFC explored for simultaneous dye decolorization and electricity
generation. 相似文献
18.
Microbial fuel cells (MFCs) are a technology that provides electrical energy from the microbial oxidation of organic compounds.
Most MFCs use oxygen as the oxidant in the cathode chamber. This study examined the formation in culture of an unidentified
bacterial oxidant and investigated the performance of this oxidant in a two-chambered MFC with a proton exchange membrane
and an uncoated carbon cathode. DNA, FAME profile and characterization studies identified the microorganism that produced
the oxidant as Burkholderia cenocepacia. The oxidant was produced by log phase cells, oxidized the dye 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS),
had a mass below 1 kD, was heat stable (121°C) and was soluble in ethanol. In a MFC with a 1000 Ω load and ABTS as a mediator,
the oxidizer increased cell voltage 11 times higher than atmospheric oxygen and 2.9 times higher than that observed with ferricyanide
in the cathode chamber. No increase in cell voltage was observed when no mediator was present. Organisms that produce and
release oxidizers into the media may prove useful as bio-cathodes by improving the electrical output of MFCs. 相似文献
19.
Performance and microbial ecology of air-cathode microbial fuel cells with layered electrode assemblies 总被引:1,自引:0,他引:1
Microbial fuel cells (MFCs) can be built with layered electrode assemblies, where the anode, proton exchange membrane (PEM),
and cathode are pressed into a single unit. We studied the performance and microbial community structure of MFCs with layered
assemblies, addressing the effect of materials and oxygen crossover on the community structure. Four MFCs with layered assemblies
were constructed using Nafion or Ultrex PEMs and a plain carbon cloth electrode or a cathode with an oxygen-resistant polytetrafluoroethylene
diffusion layer. The MFC with Nafion PEM and cathode diffusion layer achieved the highest power density, 381 mW/m2 (20 W/m3). The rates of oxygen diffusion from cathode to anode were three times higher in the MFCs with plain cathodes compared to
those with diffusion-layer cathodes. Microsensor studies revealed little accumulation of oxygen within the anode cloth. However,
the abundance of bacteria known to use oxygen as an electron acceptor, but not known to have exoelectrogenic activity, was
greater in MFCs with plain cathodes. The MFCs with diffusion-layer cathodes had high abundance of exoelectrogenic bacteria
within the genus Geobacter. This work suggests that cathode materials can significantly influence oxygen crossover and the relative abundance of exoelectrogenic
bacteria on the anode, while PEM materials have little influence on anode community structure. Our results show that oxygen
crossover can significantly decrease the performance of air-cathode MFCs with layered assemblies, and therefore limiting crossover
may be of particular importance for these types of MFCs. 相似文献
20.
Microbial fuel cells (MFCs) have been used for several years as biosensors for measuring environmental parameters such as biochemical oxygen demand and water toxicity. The present study is focused on the detection of toxic matter using a novel silicon-based MFC. Like other existing toxicity sensors based on MFCs, this device is capable of detecting the variation on the current produced by the cell when toxic compounds are present in the medium. The MFC approach presented in this work aims to obtain a simple, compact and planar device for its further application as a biosensor in the design and fabrication of equipment for toxicity monitoring. It consists on a proton exchange membrane placed between two microfabricated silicon plates that act as current collectors. An array of square 80 μm × 80 μm vertical channels, 300 μm deep, have been defined trough the plates over an area of 6 mm × 6 mm. The final testing assembly incorporates two perspex pieces positioned onto the plates as reservoirs with a working volume of 144 μL per compartment. The operation of the microdevice as a direct electron transfer MFC has been validated by comparing its performance against a larger scale MFC, run under the same conditions. The device has been tested as a toxicity sensor by setting it at a fixed current while monitoring changes in the output power. A drop in the power production is observed when a toxic compound is added to the anode compartment. The compact design of the device makes it suitable for its incorporation into measurement equipment either as an individual device or as an array of sensors for high throughput processing. 相似文献