Types Of Microbial Fuel Cells Research Articles

Analysis of the potential of the electroactive biofilm growth in a microbial fuel cell type H

Microbial fuel cells (MFC) constitute an attractive alternative as an environmental remediation technology since they can generate electrical current using organic waste as a substrate. Since the performance of MFCs depends on the characteristics of the biofilm on the anode surface, it is important to assess the genetic information of the microorganisms that grow on the electrode. For this purpose, a sewage sludge sample was obtained from a wastewater treatment plant and used to inoculate a type H MFC. Electrochemical characterization, on one hand, indicates that while the biofilm has a typical electrochemical performance reflected by the generated voltage (near 0.4 V) and by the electroactivity observed in cyclic voltammetry experiments, and on the other hand, the metagenomic analysis shows that the most abundant genera are Pseudomonacea, Nitrosomonas, Hyphomonas, and Opitutus. The study also indicates that the biofilm’s electroactive microorganisms can metabolize amino acids, lipids, and carbohydrates and possess genetic tools for ionic transport and energy production. Regarding the electron acceptor/donator capabilities, several oxidases, reductases, and complexes were identified, mainly terminal cytochrome C oxidase and respiratory complex I, which could be associated with the exoelectrogenic capacity of the microorganisms. Finally, the metagenomic information indicates that the biofilm can synthesize rhamnose, sialic acid, and alginate molecules, which could possibly be associated with the formation and consolidation of the microbial biofilm.

Key operational parameters assessment for a chromium (VI)-reducing annular upflow microbial fuel cell

Development of upflow microbial fuel cells (MFCs) is of importance since these types of MFCs can be integrated in wastewater treatment plants for the provision of continuous treatment and energy recovery. In this study, key operational parameters were assessed for a hexavalent chromium [Cr(VI)] reducing annular upflow MFC (approximately 5 L total liquid volume). The optimized operational parameters were cathode and anode hydraulic retention times of 2 days, temperature of 34 °C, influent Cr(VI) concentration of 800 mg L−1, and anode and cathode pH of 7 and 4 respectively. This study demonstrated that a parallel configuration is advantageous since it leads to a high current and power density operation due to low internal resistance when compared to series configuration. The precipitation of Cr(III) over time was demonstrated to have a potential to reduce MFC performance and operating at high influent Cr(VI) pHs (7–10) should be avoided. The optimized peak output potential difference and maximum power density achieved under parallel configuration were 896 mV and 994 mW m−3 respectively, at a current density of 1191 mA m−3. This study provides a step into developing continuous metal reducing MFCs for use in simultaneous treatment of heavy metals in wastewater and energy recovery.

New insights into microbial electrolysis cells (MEC) and microbial fuel cells (MFC) for simultaneous wastewater treatment and green fuel (hydrogen) generation

Hydrogen is the green fuel with higher eco-friendly and efficient vehicular fuel. In past hydrogen gas is derived from non-renewable resources. In recent years renewable resources are utilized for generation of bio-hydrogen gas. Hydrogen gas is preferably produced via electrochemical, photochemical, thermochemical and biochemical processes. Microbial fuel cell (MFC) and microbial electrolysis cell (MEC) are the notable systems used for hydrogen production from organic wastes and wastewater. This review mainly focuses on bio-hydrogen production from both MFC and MEC from wastewater. The mechanism, factors influencing the process, different types of MFCs, energy harvesting ways are signposted in this review. This review addresses on the difficulties in harvesting the energy as well as the economic aspect of harvested energy in detail. In MEC, microbial activity happens at anode and in electrode the hydrogen evolution occurs. Upscaling of the process is mainly influenced by the reactor design and microbiology. Performance of various catalysts on hydrogen evolution are discussed in detail. The scalability of integrating MFC and MEC needs to be decoded in near future for the better of hydrogen production and achieving sustainable development goals (SDGs).

The Study of Plant Microbial Fuel Cell for Alternative Energy Source

Plant Microbial Fuel Cell (P-MFC) is one of Microbial Fuel Cell type. It can produce electricity and source for plant living. By using the humus soil in the anode chamber, the electron can flow to the cathode chamber. The principle of Plant Microbial Fuel Cell is same with the battery. It flows the direct current. This research makes dual chamber of P-MFC prototype. The salt bridge is used as connection between anode chamber to cathode chamber. The humus soil comes from burning organic waste. Its color is black and contains a lot of microbes. The plant selected in this research was Water Spinach. The number of water spinach were 20 and 25 stems. P-MFC which has more Water Spinach will produce more voltage and current than the others. For 25 Water Spinach, P-MFC produced 762.4 mV no-load average voltage and 125.8 mV, 085 mA for load condition. The result was bigger caused by for more plants will be more microbes resulted in the humus soil.

Microbial Fuel Cell as New Renewable Energy for Simultaneous Waste Bioremediation and Energy Recovery

Microbial fuel cell (MFC) is an outstanding technology recently creating the headlines relating to energy and environment field that been discovered since the earlier 20th century. It has been furthered implemented for energy renewable through simultaneous bioremediation of wastes. MFC works by converting chemical energy store in the waste into electrical energy with the help of selected microorganisms. Regarding to this, the principle of bioremediation was applied using MFC as the renewable energy where the microorganisms consume the substrate thus generating electrical energy. Many studies done by researches are mostly focusing on MFC utilizing waste and measuring the power generation on different type of MFC but lack of studies on the effect of series and parallel circuit in MFC setup and how does it differentiate the outcome of the studies. This paper reviews the history, working principle, design of MFC, classification of different substrates and its power output and the effect of series and parallel circuit of MFC setup for simultaneous bioremediation and energy recovery.

Conversion of lignocellulose residue obtained from biorefinery stream to electricity by microbial fuel cell

In general, lignocellulose biorefinery has the main functions to fractionate biomass compositions and convert them to value-added products. However, leftover organic compounds in output streams are mixed with large amounts of wastewater becoming the cost and burden for treatment. Therefore, to close the loop of circular economy, this review paper explores the potential of microbial fuel cells (MFCs) as a sustainable and efficient way to convert lignocellulose residue, a byproduct of biorefinery processes, into electricity. Lignocellulose residue is a complex mixture of carbohydrates and lignin that is often difficult to dispose of properly. By using MFCs, this waste material can be converted into valuable energy while reducing the environmental impact of its disposal. The paper covers the different types of MFCs, their working principles, and their potential application in lignocellulose residue conversion. It also discusses the factors that affect the performance of MFCs, including substrate availability, electrode material, and reactor design. Additionally, the paper reviews the current state of research in this area, highlighting recent advances and identifying areas for future exploration. Overall, this review paper demonstrates the promise of MFCs as a sustainable and innovative approach to converting lignocellulose residue into electricity.

Research on Microbial Fuel Cell in Water Treatment and Power Generation

With the development of economics, water pollution is becoming increasingly serious, and the existing sewage treatment technology has high energy consumption. Therefore, the development of low energy consumption, safe and environmental protection technology is the trend of in further. Microbial fuel cell (MFC), as an emerging comprehensive technical method for wastewater disposal, shows great application prospects. In this work, the working principle and function of different types of MFC, the application of MFC in sewage treatment field, and the shortcomings of MFC devices to be perfected in the market are discussed.

MFC based in situ electrocatalytic persulfate activation for degradation of 2,4-dichlorophenol: Process and mechanism

Electrocatalytic persulfate (PS) generation of sulfate radicals has been extensively studied for the removal of organic pollutants, while continuous electricity output causes high energy consumption. Microbial fuel cell (MFC) is an environmentally friendly approach that can catalyze PS for degradation of pollutants through bioelectricity and achieve electricity recovery and utilization at the same time. In this study, a MFC based on electrocatalytic PS activation in cathode (PS-MFC) was constructed to remove 2,4-dichlorophenol (2,4-DCP) with simultaneous electricity recovery. Results showed that 2,4-DCP was successfully removed by PS-MFC with a maximum removal rate of 68.7% after 220 mins of reaction, and the removal process followed pseudo-second-order kinetic. In addition to the wide pH reaction range (pH 3–11), PS-MFC exhibited excellent electrical performance with a higher maximum power density (300.28 mW/m2) than reported studies of the similar type of MFC. Active species for the degradation of 2,4-DCP by PS-MFC system are O2•−, •OH, SO4•−and O21, with O2•− and •OH accounting for major part. The degradation pathway of 2,4-DCP in PS-MFC was proposed by free radical quenching experiments and intermediate product analysis. This work provided a green and sustainable solution for the removal of refractory organic pollutants and promoted research for the further practical application of MFCs.

Sensitivity enhancement for microbial fuel cell type oil sensor by regulation of anode area, external resistance and substrate concentration

To promote application of the microbial fuel cell (MFC)-based oil sensor in monitoring oil leak risks of oil pipelines and to overcome the influence of signal fluctuation, the sensor sensitivity needs to be enhanced. Simple and viable start-up measures such as regulating anode area, external resistance and substrate concentration were implemented to investigate their influence on the sensitivity. Results show that enlarging anode area and lessening external resistance will significantly promote the sensitivity (change of current signal per oil amount). Increasing anode area from 3.1 to 9.6 cm2 resulted in a 711 % increase in the initial sensitivity and a 358 % increase in the average sensitivity. Decreasing external resistance from 1300 to 400 Ω led to a 797 % increase in the initial sensitivity and a 378 % increase in the average sensitivity. While controlling substrate concentration from 155.7 to 500.7 mg-COD/L had a much smaller impact on the sensitivity. Manipulating substrate concentration over an augmented range (41.2–500.7 mg-COD/L) showed that insufficient substrate (< 80 mg-COD/L) induced a drastic current drop. A theoretical sensitivity formula was derived from a data fitting model based on charge conservation. The formula reveals that a sensitivity factor relating to the ratio of ORR and oxygen transfer is key to enhancing sensitivity, which was verified to have a strong positive correlation with current by data analysis and EIS. In general, this study shows that measures to elevate current will significantly enhance sensitivity besides keeping substrate concentration at a high level is a prerequisite for maintaining it.

Microbial fuel cell compared to a chemostat

Microbial Fuel Cells (MFCs) represent a green and sustainable energy conversion system that integrate bacterial biofilms within an electrochemical two-electrode set-up to produce electricity from organic waste. In this review, we focus on a novel exploratory model, regarding “thin” biofilms forming on highly perfusable (non-diffusible) anodes in small-scale, continuous flow MFCs due to the unique properties of the electroactive biofilm. We discuss how this type of MFC can behave as a chemostat in fulfilling common properties including steady state growth and multiple steady states within the limit of biological physicochemical conditions imposed by the external environment. With continuous steady state growth, there is also continuous metabolic rate and continuous electrical power production, which like the chemostat can be controlled. The model suggests that in addition to controlling growth rate and power output by changing the external resistive load, it will be possible instead to change the flow rate/dilution rate.

Modelling of self-sustainable microbial fuel cell type oil sensors based on restricted oxygen transfer and two-population competition

Oil leaks during oil industrial chain pose threats to the ecosystem. The microbial fuel cell-type oil sensor has been developed for early warning of such issues. Oil contacting with the sensor restricts oxygen availability and triggers correlative signal anomaly which serves as indicative of the oil presence. To extend its application for the real world, modelling of the sensor is required to pre-describe the signal behavior under unknown conditions. Therefore, by integrating Butler-Volmer, restricted oxygen transfer (ROT) and Monod equations, a dynamic ROT-MFC model with sufficient substrate precondition was developed. The ROT-MFC model was trained on the experimental single-oil-shock test (R 2 = 0.996) and validated by the experimental sequential-shocktest (R 2 = 0.998). Numerical analysis of the trained ROT-MFC model indicates that the single-shock detection has higher sensitivity (≥40.6 mV/detection) and the sequential-shocks detection spends a shorter response time (≤2.2 h). Besides, the sequential-shocks detection with proper strategy is more applicable due to flexible options on detection limit and working range. The model was further evolved into the TPC-ROT-MFC model by introducing a two-population competition (TPC) theory to describe performance under limited substrate conditions. Results indicate a critical substrate concentration range (42.1 to 62.8 mg-COD/L) for dividing baseline steadiness, and that the impact of substrate concentration on anodic charge transfer coefficient soars when the substrate concentration lessens furtherly. This sensor model is relatively easy to implement and may enhance practical use for design and operation.

Rainwater-driven microbial fuel cells for power generation in remote areas.

The possibility of using rainwater as a sustainable anolyte in an air-cathode microbial fuel cell (MFC) is investigated in this study. The results indicate that the proposed MFC can work within a wide temperature range (from 0 to 30°C) and under aerobic or anaerobic conditions. However, the rainwater season has a distinct impact. Under anaerobic conditions, the summer rainwater achieves a promised open circuit potential (OCP) of 553 ± 2 mV without addition of nutrients at the ambient temperature, while addition of nutrients leads to an increase in the cell voltage to 763 ± 3 and 588 ± 2 mV at 30°C and ambient temperature, respectively. The maximum OCP for the winter rainwater (492 ± 1.5 mV) is obtained when the reactor is exposed to the air (aerobic conditions) at ambient temperature. Furthermore, the winter rainwater MFC generates a maximum power output of 7 ± 0.1 mWm−2 at a corresponding current density value of 44 ± 0.7 mAm−2 at 30°C. While, at the ambient temperature, the maximum output power is obtained with the summer rainwater (7.2 ± 0.1 mWm−2 at 26 ± 0.5 mAm−2). Moreover, investigation of the bacterial diversity indicates that Lactobacillus spp. is the dominant electroactive genus in the summer rainwater, while in the winter rainwater, Staphylococcus spp. is the main electroactive bacteria. The cyclic voltammetry analysis confirms that the electrons are delivered directly from the bacterial biofilm to the anode surface and without mediators. Overall, this study opens a new avenue for using a novel sustainable type of MFC derived from rainwater.

Investigation of Polymer Biofilm Formation on Titanium-Based Anode Surface in Microbial Fuel Cells with Poplar Substrate

Microbial fuel cells (MFCs) have attracted attention by directly converting the bioelectrochemical energy possessed by the organic materials that make up the biomass into electrical energy. In this study, the relationship between the biofilm formed on the titanium-based anode electrode surface, and the chemical composition of the substrate, the energy source of MFC, was investigated. For this, MFCs were made by using poplar wood shavings rich in organic material as the substrate, titanium-based material as the anode electrode, and natural soil as bacterial habitat. Three types of MFCs containing 1%, 10%, and 20% poplar wood shavings by weight were made and named P1-MFC, P2-MFC, and P3-MFC, respectively. According to electrochemical analysis, P3-MFC provided the highest open circuit voltage with 490 mV value, and the highest power density with 5.11 mW/m2 value compared to other MFCs. According to optical microscopy examinations, there were Bacillus and Coccus species of bacteria in the soil structure, and these bacteria also existed around the fiber of poplar wood shavings in MFCs. Scanning electron microscopy (SEM), energy-dispersive spectrum (EDS), and Fourier transform infrared spectroscopy (FTIR) analysis showed that MFCs formed biofilm in the titanium-based anode, and the chemical composition of this biofilm with poplar tree was similar. As a result, due to the catalysis reactions of bacteria, the titanium-based anode electrode surface was coated with polymer biofilm released from poplar wood shavings.

Effects of cathode/anode electron accumulation on soil microbial fuel cell power generation and heavy metal removal

Microbial fuel cells (MFCs) with different electrode configurations were constructed to study the mechanism of influence of multiple current paths on their electrical performance and the removal of heavy metals in soil. Three types of MFCs were constructed, namely, double anode–single cathode (DASC), single anode–dual cathode (SADC), and single anode–single cathode (SASC). The total electricity generation of the three kinds of MFC was similar: 143.44 × 10–3 mW, 114.90 × 10–3 mW, and 132.50 × 10–3 mW, respectively. However, the maximum voltage and cathode current density produced by a single current path differed significantly. The corresponding values were 0.27, 0.23, and 0.42 V and 0.130, 0.122, and 0.096 A/m 2, respectively. The SASC had the best electricity generation performance. Based on a limited reduction rate of oxygen at the cathode, the accumulation of cathode electrons was facilitated by the construction of multiple current paths in the MFC, which significantly increased the cathode electron transfer resistance and limited the electricity generation performance of the MFC. However, at the same time, the construction of multiple current paths promoted output of more electrons in the anode, reducing the retention of anode electrons and anode electron transfer resistance. The heavy metal removal efficiencies of SASC, DASC, and SADC were 2.68, 2.18, and 1.70 times that of the open circuit group, respectively. The migration of heavy metals in the soil depended mainly on the internal electric field intensity of the MFC rather than the total electricity generation. As the internal electric field intensity increased, the removal efficiency of heavy metals in the MFC increased.

Microbial fuel cells, a renewable energy technology for bio-electricity generation: A mini-review

The unsustainable nature and the environmental impact of fossil fuels have shifted attention to renewable energy and fuel cells, especially in the transportation sector. In this study, the generation of electricity based on the electrons released from biochemical reactions facilitated by microbes is evaluated. Microbial fuel cell (MFC) represents an eco-friendly approach to generating electricity while purifying wastewater concurrently, achieving up to 50% chemical oxygen demand removal and power densities in the range of 420–460 mW/m2. The system utilizes the metabolism power of bacteria for electricity generation. This mini-review is quite comprehensive. It is different from other reviews, it is all-inclusive focusing on the; types of MFCs; substrates and microbes; areas of applications; device performances; design, and technology configuration. All these were evaluated, presented and discussed which can now be accessed in a single paper. It was discovered that higher power density and coulombic efficiency could be achieved through proper selection of microbes, mode of operation, a suitable material for construction, and improved MFC types. Also, the full-scale application of MFC is impeded by materials cost and the wastewater low buffering capacity. Though the electricity generated is still at the demonstration stage, to date, there is no industrial application. Therefore, this study reviewed articles on the technology to set new and insightful perspectives for further research and highlighted steps for scale-up while reinforcing the criteria for microbe selection and their corresponding activity.

Graphitic carbon nitride/carbon brush composite as a novel anode for yeast-based microbial fuel cells

A biocompatible graphitic carbon nitride (g-C3N4) was prepared on the surface of carbon brush fiber (CB) via a facile one-step preparation method. The prepared g-C3N4 formed a composite with the carbon brush’s fibers (g-C3N4@CB), as shown from the XRD analysis. The g-C3N4@CB was used as an anode in a yeast-based microbial fuel cell (MFC), and demonstrated an outstanding performance compared to plain CB. An anode potential of −0.27 V “vs. Ag/AgCl” and an open-circuit voltage of 0.77 V was obtained in the case of the composite electrode, compared to −0.1 V vs. Ag/AgCl and 0.62 V, respectively, in the case of the CB. The cell using the composite electrode demonstrated a maximum power of 772 mWm−2, which is twelve times that obtained using the CB. The outstanding performance of the composite electrode can be credited to the biocompatibility of the composite anode and its roughness, which improved the yeast biofilm formation and decreased the ohmic resistance. This is the first report involving the application of g-C3N4 in a yeast-based MFC, and it demonstrated promising results which can be used for other types of MFCs.

From Waste to Wealth: Making Millivolts from Microbes!

Biofuels can reduce our reliance on fossil energy sources while also protecting our environment. A Microbial Fuel Cell (MFC) is a system in which microorganisms produce electricity while performing their normal metabolism. The purpose of this project was to engineer a series of MFCs and manipulate circuit components to optimize voltage production. Each two-chamber MFC was created using creek mud, presumably rich in anaerobic exoelectrogenic bacteria, in the anode chamber and water in the cathode chamber. Four types of MFCs (three in each group) were constructed: 1) Mud in anode and water in cathode chambers; 2) Mud and sucrose in anode and water in cathode chambers; 3) Mud in anode and water and iron filings in cathode chambers; 4) Mud and sucrose in anode and water and iron filings in cathode chambers. Voltage output was recoded over twelve days. MFCs with iron filings (alone or with sucrose) consistently produced more voltage than the MFC with mud alone. Adding iron filings to the cathode chamber increased voltage output by 49%. While sugar alone in the anode chamber did not increase voltage output, the combination of sugar in the anode and iron filings in the cathode chambers did increase voltage output by 69% when compared to the MFC with mud alone. Our experiment demonstrated that MCFs can be optimized by manipulating bacterial substrate and using metal electron acceptors. We must invest in our planet’s future by supporting large scale research on MFCs that can produce clean electric energy and purify environmental waste.

Bioelectricity Production Using Microbial Fuel Cell–a Review

This paper summarised different methods used for the electrical power generation using microorganisms in MFC. In the past decade, Microbial Fuel Cells (MFC) attracted many researchers due to their ability to convert organic waste into electric currents by the usage of microorganisms. It has been developing as a great source of renewable energy. This device makes use of simple cathode and anode compartments and a separating membrane. This can be efficiently used for power generations and wastewater treatments. Microbial electrolysis cell (MEC), a type of MFC is also used in generating Hydrogen energy from various biological matters. The performance of MFC totally depends upon the nature of microorganisms, electrodes selected, and the separating membarane used. MFCs serve as a sustainable and alternate energy source to reduce the pollution caused by industrialization. In this review, a detailed explanation about MFC and different ways of generating bioelectricity and hydrogen from wastewater treatment are explained.

Investigating the potential of locally sourced wastewater as a feedstock of microbial desalination cell (MDC) for bioenergy production.

Freshwater sources are limited and access to clean water is an acute challenge in recent decades. The sustainable water treatments methods are need of time and water desalination is one of the most interesting technology. Most desalination technologies are required high energy input while Microbial Desalination Cells (MDCs) represent a sustainable option that has added benefit of solving the ever-increasing wastewater treatment and management problem. MDCs are a customized type of Microbial Fuel Cells (MFCs) that depend on the electric potential generated by organic media to decrease salt concentration by electro-dialysis and give an unconventional way of clean water production. In this research, various experiments were conducted to examine the desalination ability of an indigenously designed experimental setup using domestic wastewater inoculated with sewage sludge under identical conditions. The electrochemical properties of the system, comprising the polarization curve and Electrochemical Impedance Spectroscopy (EIS), were examined along with the scope of chemical oxygen demand (COD) exclusion, to distinguish the cell behaviour. Furthermore, acidic water and Phosphate Buffer Solution (PBS) were tested as potential catholytes compared to the performance of the wastewater was gauged at various salt concentrations. The maximum salt removal efficiency was 31%, power density and current density were 32 mW-m-2 and 246mA-m-2 respectively at a salt concentration of 35g-L-1 that decreases with a decline in salt concentration. The maximum achieved power density and current density were 32 mW-m-2 and 246mA-m-2 respectively. The applied method has huge potential to scaleup for large scale application in coastal regions.

A COMPARATIVE STUDY OF ELECTRICITY GENERATION FROM INDUSTRIAL WASTEWATER THROUGH MICROBIAL FUEL CELL

The present study presents a comparison of the electricity generation from industrial wastewater via Microbial Fuel Cell (MFC). Four experimental setups with four types of MFC were developed for this study. For MFC 1, 75% of wastewater from Factory A added to a fixed concentration of cow manure to obtain a solution of 600ml in the anodic chamber while adding distilled water into the cathodic chamber. Contrastingly, for MFC 2, 75% of wastewater from Factory A was added to a fixed concentration of cow manure to obtain a solution of 600ml in the anodic chamber, whereas distilled water mixed with 15g of potassium ferricyanide was added to the cathodic chamber. For MFC 3, a similar setup was made as in MFC 1 though it utilizes wastewater from Factory B. MFC 4 in return replicated the setup of MFC 2, yet the wastewater was collected from Factory B. Two (2) tests were conducted where Test 1 was to compare the voltage readings from MFC 1 and MFC 3, while Test 2 was for MFC 2 and MFC 4. It was observed that the voltage produced by the wastewater from Factory A was higher than that of voltage produced from Factory B by 41% in test 1 and 82.4% in test 2. Interestingly, the addition of potassium ferricyanide further increased the voltage by 63.17% when comparing between MFCs 4 and 3, while 111% for MFCs 2 and 1, respectively. Hence, it can be deduced that the addition of an external electron acceptor such as the potassium ferricyanide greatly increases the voltage produced. For future studies, other types of external electron acceptors could be tested in identifying its potential in improving the capability of the MFC.Keywords: microbial fuel cell, natural mixes, isoelectronic microbes, ecological concern