Microbial Fuel Cell Research Research Articles

Is it time to start moving soil microbial fuel cell research out of the lab and into the field?

Soil microbial fuel cells (SMFCs) function as bioelectrochemical energy harvesters that convert electrons stored in soil organic matter into useful electrical energy. Broadly, an SMFC comprises three essential components: an anode buried in the soil (the negative terminal), a colony of exoelectrogenic microorganisms residing on this anode, and a cathode (the positive terminal). As the exoelectrogens respire, they release electrons to the anode, which acts as an external receptor. These released electrons then flow through a load (e.g. a resistor), connecting the anode and cathode. Though minuscule, the electrical power produced by SMFCs has a number of potential applications such as sustaining low-power embedded electronics, pollutant remediation, or as a bio-sensing proxy for soil qualities and microbial activity. This discussion aims to emphasize the potential of SMFCs in addressing real-world environmental issues and to generate interest in the larger scientific community for broad interdisciplinary research efforts, particularly in field deployments.

Microbial Fuel Cells Performance Evaluation through the Application of Fuzzy Logic

Objective: This work aimed to employ fuzzy logic combined with the design of experiments technique to statistically evaluate how the microbial fuel cells operating parameters influence their performance. Theoretical Framework: Microbial fuel cells (MFC) are a technology of interest in the current scenario as they allow simultaneously promoting the biotreatment of waste and the bio generation of electrical energy. Methodology: Through a bibliographical search based on publications on Google Scholar platform over the last 10 years, it was noticed that anode area, external electrical resistance and reactor volume are the most reported input parameters in MFC research and current density and power density are the output parameters most frequently portrayed in these studies, which is why these variables were selected for statistical investigation. Results and Discussion: The results showed that, for both outputs studied, reactor volume and anode area showed a positive effect, while the external electrical resistance showed a negative effect. It was also possible to develop mathematical models that indicated the relationship between the input and output variables studied, with statistical significance for power density model (R2 = 86%). Originality: Applying computational simulations and subsequent design of experiments to obtain results in accordance with those obtained experimentally in the laboratory.

Microbial Fuel Cell, Their Type, Working Principle and Different Factors Affecting Their Performance: A Review

Microbial fuel cell (MFC) is a green technology and is an alternative energy resource of fossil fuels. MFC is the class of Bio-electro-chemical patterns with novel property, like wastewater treatment, electricity generation and biosensor operation. MFCs are ingenious devices that harness the power of bio-electrochemical processes to generate electric current by breaking down organic waste found in wastewater. These systems establish a fascinating connection between microbial metabolism and electricity production. The microbes within the MFCs thrive on the nutrients present in their environment and convert the energy stored in the organic matter into usable electricity. This electrical energy can be effectively utilized to power various essential portable electronic devices such as mobile phones, laptops, TVs, air dryers, threading machines, chargeable torches, as well as devices used in the air force, outer space, and weather stations. The maximum power produced by MFC using an Iron anode is 170 mW·m-2, 0.645 v, while MFCs have better power efficiency in mix culture Microbs 30 mA, 3,600 mW·m-2. It has been observed that MFCs equipped with carbon-based electrodes tend to have a longer lifespan compared to those using metal-based electrodes. However, one drawback of carbon-based electrode MFCs is that they generally exhibit lower power output. In recent times, the investment focus on MFC research has significantly improved the analysis of its chemical, microbiological, and electrochemical aspects. These advancements have led to notable enhancements in the sensing capabilities of MFCs. In this review, we have summarized the MFCs, their working principle, types, composition and the various factors which affect the performance of these MFCs.

Waste treatment and Sustainable Bioelectricity Generation using Microbial fuel cell

In the last decade, great attentions have been paid to microbial fuel cells (MFC) due to the possibility to be the solution for the three bigger world project – energy security, climate changes and waste management. Different from all the conventional wastewater treatment which are energy intensive, MFC can use waste as substrate/fuel to directly generate electricity through microbial reactions in anode and microbial/enzymatic/abiotic electrochemical reactions in cathode. In this sense, the MFC is an emerging technology for treat waste and produce wealth products (energy and some added value substance – organic acids, nutrients). Although, there are a large number of research in new materials and operational conditional to improve the MFC performance, as yet there are practical barriers, such as low power generation, expensive electrode materials and the inability to scale up MFC. Therefore, this work summarizes information about the recent advances in MFC research, focused on MFC configurations, material electrodes, and performances. Limitations and challenges in applying MFC to treat waste are also discussed, moreover future perspective pointed the new hot topics to solve these problems.

Optimizing total ammonia–nitrogen concentration for enhanced microbial fuel cell performance in landfill leachate treatment: a bibliometric analysis and future directions

Untreated landfill leachate can harm the environment and human health due to its organic debris, heavy metals, and nitrogen molecules like ammonia. Microbial fuel cells (MFCs) have emerged as a promising technology for treating landfill leachate and generating energy. However, high concentrations of total ammonia–nitrogen (TAN), which includes both ammonia and the ammonium ion, can impede MFC performance. Therefore, maintaining an adequate TAN concentration is crucial, as both excess and insufficient levels can reduce power generation. To evaluate the worldwide research on MFCs using landfill leachate as a substrate, bibliometric analysis was conducted to assess publication output, author-country co-authorship, and author keyword co-occurrence. Scopus and Web of Science retrieved 98 journal articles on this topic during 2011–2022; 18 were specifically evaluated and analysed for MFC ammonia inhibition. The results showed that research on MFC using landfill leachate as a substrate began in 2011, and the number of related papers has consistently increased every 2 years, totaling 4060 references. China, India, and the USA accounted for approximately 60% of all global publications, while the remaining 40% was contributed by 70 other countries/territories. Chongqing University emerged as one of the top contributors among this subject’s ten most productive universities. Most studies found that maintaining TAN concentrations in the 400–800 mg L−1 in MFC operation produced good power density, pollution elimination, and microbial acclimatization. However, the database has few articles on MFC and landfill leachate; MFC ammonia inhibition remains the main factor impacting system performance. This bibliographic analysis provides excellent references and future research directions, highlighting the current limitations of MFC research in this area.

Benchmark and strategy development for microbial fuel cells in industrial wastewater treatment

The chemical energy hidden in wastewater can be extracted, turning an energy‐intensive treatment process into an energy‐independent one. However, conventional aerobic treat‐ ment is very energy intensive, and anaerobic treatment requires a post‐treatment step to meet stringent discharge requirements. Therefore, Microbial Fuel Cells (MFCs) have attracted a lot of attention because of their ability to extract electrical energy directly from wastewater during the treatment process. Since combustion losses can be avoided, theoretically the greatest energy value can be obtained from the organic load. However, most MFC research is currently still taking place on a laboratory scale in the treatment of synthetic or municipal wastewater. Commercialization of MFC technology will require large‐scale plants, for which a suitable MFC design and operation concepts must first be identified, since neither configuration nor operating system has been clearly established yet. In addition, no specific concepts and application fields currently exist for the treat‐ ment of industrial wastewater.Consequently, with regard to MFCs in industrial wastewater treatment, the aim of this work is to develop a benchmark that serves for modeling the required overall efficiency of MFCs and to identify the most relevant key factors in order to derive enhancement strate‐ gies. By providing an overview of current MFCs in industrial wastewater treatment and developing a benchmark, the targets for long‐term operation of MFCs can be established allowing critical factors for design and operation to be identified. The resulting enhance‐ ment strategies were validated and the overall evaluation with the developed benchmark allowed an assessment regarding the commercialization potential.Compared to the first MFC design (MFC 1.0), the enhanced MFC design (MFC 2.0) increased the power density by a factor of up to 11 and extended the long‐term stability to one year by increasing the specific cathode surface area and reducing the electrode spacing in conjunction with avoiding fiber clogging on the anode side. In addition to using beneficial brewery wastewater with high content of easily degradable organic acids and high conductivity, the performance of the MFC was further stabilized and improved by changing the operating mode to continuous operation and reducing the hydraulic re‐ tention time to 6 h, resulting in a mean organic removal rate of 6.5 ± 1.9 kg/(m3 · d). Although the overall energy efficiency is low compared to anaerobic treatment, the enor‐ mous wastewater treatment potential forms the basis for MFCs to become an alternative to conventional treatment technologies if self‐sufficient treatment is targeted. Due to the wide range of operating conditions and the modularity of stack systems, MFCs can become a promising option especially for industrial wastewater treatment.

Microbial Fuel Cell Construction Features and Application for Sustainable Wastewater Treatment

A microbial fuel cell (MFC) is a system that can generate electricity by harnessing microorganisms’ metabolic activity. MFCs can be used in wastewater treatment plants since they can convert the organic matter in wastewater into electricity while also removing pollutants. The microorganisms in the anode electrode oxidize the organic matter, breaking down pollutants and generating electrons that flow through an electrical circuit to the cathode compartment. This process also generates clean water as a byproduct, which can be reused or released back into the environment. MFCs offer a more energy-efficient alternative to traditional wastewater treatment plants, as they can generate electricity from the organic matter in wastewater, offsetting the energy needs of the treatment plants. The energy requirements of conventional wastewater treatment plants can add to the overall cost of the treatment process and contribute to greenhouse gas emissions. MFCs in wastewater treatment plants can increase sustainability in wastewater treatment processes by increasing energy efficiency and reducing operational cost and greenhouse gas emissions. However, the build-up to the commercial-scale still needs a lot of study, as MFC research is still in its early stages. This study thoroughly describes the principles underlying MFCs, including their fundamental structure and types, construction materials and membrane, working mechanism, and significant process elements influencing their effectiveness in the workplace. The application of this technology in sustainable wastewater treatment, as well as the challenges involved in its widespread adoption, are discussed in this study.

Bibliometric analysis of artificial intelligence algorithms used for microbial fuel cell research

Abstract Research regarding microbial fuel cells has been stimulated to reduce the operating costs and energy consumption of conventional wastewater treatment, and increase its profitability. However, these devices are challenging to study due to their complexity and sensitivity to both internal and external factors. Artificial intelligence (AI) has been used to analyze microbial fuel cells as an effective alternative to the use of mathematical models, which are still in development. In this study, the main goals were to perform the first bibliometric analysis of AI applied to microbial fuel cell research and to find the most popular algorithms used to date. Using the Web of Science database, a total of 102 articles published between 1999 and 2022 were retrieved. The cumulative number of articles has greatly increased over the past 10 years. About 55% were contributed by researchers from China and USA, leading among 20 countries. Some 50 algorithms were used, with principal component analysis and feed-forward neural networks being the most popular used to study and optimize microbial fuel cells.

Determination of optimum retention time in an air–cathode single-chamber microbial fuel cell batch-mode reactor by comparing different substrate types and concentrations

The disadvantages of the air–cathode single-chamber microbial fuel cell (AC-SCMFC) performance can be caused by numerous factors, and retention time (RT) is one such factor. It is difficult to conclude the ideal RT run for the specific tests under the same conditions. To determine the optimum RT for various types of microbial fuel cell (MFC), an AC-SCMFC batch-mode reactor was carried out by comparing different types and concentrations of substrates based on the main parameters of organic removal and power generation. The AC-SCMFC reactor was designed for the effective working volume of 500 mL and operated for 52 d in batch mode with factors being significantly correlated with the performance of the MFC reactor, which were two different substrates, sucrose and acetate, and three different chemical oxygen demand (COD) levels of 400; 1000, and 2500 mg/L (low, medium, and high, respectively) equipped with two graphene nanoplatelets (GNPs)-based electrodes connected to 100 Ω resistance and plugged onto a data logger. The results of this study indicated a significant pattern at the medium level, at which the optimum RT of sucrose was achieved at 24 h and that of acetate at 48 h. In comparison, the performances pattern at low and high levels of both substrates was insignificant to determine the optimum RT. For further application, the recommended RT for both substrates at any concentration is 24 h due to high overall performance, and the optimum RT established in this study could be applied to all types of MFC research, particularly in oxidizable or biodegradable organic ranges, which ensures high performance.

A Comprehensive Review on Oxygen Reduction Reaction in Microbial Fuel Cells

The focus of microbial fuel cell research in recent years has been on the development of materials, microbes, and transfer of charges in the system, resulting in a substantial improvement in current density and improved power generation. The cathode is generally recognized as the limiting factor due to its high-distance proton transfer, slow oxygen reduction reaction (ORR), and expensive materials. The heterogeneous reaction determines power generation in MFC. This comprehensive review describes-recent advancements in the development of cathode materials and catalysts associated with ORR. The recent studies indicated the utilization of different metal oxides, the ferrite-based catalyst to overcome this bottleneck. These studies conclude that some cathode materials, in particular, graphene-based conductive polymer composites with non-precious metal catalysts provide substantial benefits for sustainable development in the field of MFCs. Furthermore, it also highlights the potentiality to replace the conventional platinum air cathode for the large-scale production of the next generation of MFCs. It was evident from the experiments that cathode catalyst needs to be blended with conductive carbon materials to make cathode conductive and efficient for ORR. This review discusses various antifouling strategies for cathode biofouling and its effect on the MFC performance. Moreover, it also depicts cost estimations of various catalysts essential for further scale-up of MFC technology.

Microbial Fuel Cells: An Alternate Approach for Bioelectricity Generation and Waste Management

Microbial Fuel Cells (MFCs) are the device that involves bacteria and organic matter, to generate electrical current via bacterial metabolism from a wide range of organic and inorganic substrates. MFCs are novel bioreactors, that convert chemical energy into electrochemical energy through bio-catalysis of various wastes (agriculture, food, households, food processing industries) using microorganisms. MFC is a promising approach that offers direct, clean, green energy generation, ease of waste recyclability, and by-product utilization of different sources. In recent, MFCs research advances related to electrode development and utilization of suitable different rural and urban wastes is a significant interest in the MFC application. Hence in a large-scale application, the MFC concept is one of the effective technologies for the management of different wastes and is simultaneously used for electricity generation to cater to the energy demand in rural or remote areas that are not linked to the electric grid. MFCs help reduce the global energy crisis and reduce the pressure on non-renewable energy resources.

Mapping the field of microbial fuel cell: A quantitative literature review (1970–2020)

Microbial fuel cell (MFC) has received much attention in the last decade as a promising technology to simultaneously generate electricity and decontaminate wastewater. This study aims to quantitatively review the published literature on MFC, published in the period of 1970–2020, based on the Web of Science (WoS) database. For the first time in literature, a comprehensive quantitative review of MFC has been conducted by employing the technique of bibliometric and content analyses. A total of 11,397 publications have been retrieved from WoS, out of which 81.6% are research articles. The evaluation in the field of MFC has been mapped in various categories, such as publication history, publication distribution, subject category distribution, leading journals, leading countries and leading organizations in MFC research. Additionally, content analysis has been conducted to unearth the research trends in MFC; and some hot research topics in MFC have been spotted. Results depict that the period 2011–2020 has been the most appreciating era for MFC research, as it contributed 87% of the total publications. Among the subject categories, energy fuel and microbiology lead with contributions of 26.5% for each, butthe overall growth of the energy fuel category in the last decade has been the highest. Out of 1,147 journals publishing MFC research, Bioresource Technology is the leading one; and countries like China, USA and India are the main hub of MFC research with 26.47%, 16.95% and 7.69% contributions in publications, respectively. The hottest topics in MFC research are nanoparticles, catalysts, air electrodes, graphene electrodes, power enhancement, air cathode and nitrogen removal. Moreover, major research areas are engineering, energy fuels and biotechnology with each contribution 26.5% of the total publications.

Microbial fuel cells: a comprehensive review for beginners.

Microbial fuel cells (MFCs) have shown immense potential as a one-stop solution for three major sustainability issues confronting the world today-energy security, global warming and wastewater management. MFCs represent a cross-disciplinary platform for research at the confluence of the natural and engineering sciences. The diversity of variables influencing performance of MFCs has garnered research interest across varied scientific disciplines since the beginning of this century. The increasing number of research publications has made it necessary to keep track of work being carried out by research groups across the globe and consolidate significant findings on a regular basis. Review articles are often the nodal points for beginners who are required to undertake an exploratory survey of literature to identify a suitable research problem. This 'review of reviews' is a ready-reckoner that directs readers to relevant reviews and research articles reporting significant developments in MFC research in the last two decades. The article also highlights the areas needing research attention which when addressed could take this technology a few more steps closer to practical implementation.

In situ carbon felt anode modification via codeveloping Saccharomyces cerevisiae living-template titanium dioxide nanoclusters in a yeast-based microbial fuel cell

Titanium dioxide (TiO2) nanoclusters grown in situ by Saccharomyces cerevisiae as a living-template atop a seeded and polyethylenimine functionalized carbon felt are explored for the first time for the enhanced performance of the anode within a yeast-based microbial fuel cell (MFC). Widespread, extensive, and synergistic growth of both the yeast biofilm and TiO2 nanoclusters are observed on the hydrophilic surface of the functionalized carbon felt fibers. The entirely green and inexpensive process required only the use of a nanoparticle seed that also acts as the nanoparticle growth initiator: titanium(IV) oxide anatase. The structure and morphology of the TiO2 nanostructures are examined through optical measurements after full experimentation within a yeast-based MFC system. Due to the extensive evocation of the exopolysaccharides matrix of the yeast through the well-timed introduction of the nanoparticle growth initiator, the yeast biofilm is beneficially affected by the presence of the TiO2 nanoclusters, thus improving the yeast biofilm maturation and electrochemical behaviour. How the yeast biofilm reacts to the invasion of foreign metallic nanoparticles and how this is beneficial to MFC research are explored. The best power density of the MFC achieved through this method was 25.9 ± 6.2 W m−2, an astounding value that far exceeds similar modification techniques to the MFC anode.

Biophotovoltaics: Green Power Generation From Sunlight and Water.

Biophotovoltaics is a relatively new discipline in microbial fuel cell research. The basic idea is the conversion of light energy into electrical energy using photosynthetic microorganisms. The microbes will use their photosynthetic apparatus and the incoming light to split the water molecule. The generated protons and electrons are harvested using a bioelectrochemical system. The key challenge is the extraction of electrons from the microbial electron transport chains into a solid-state anode. On the cathode, a corresponding electrochemical counter reaction will consume the protons and electrons, e.g., through the oxygen reduction to water, or hydrogen formation. In this review, we are aiming to summarize the current state of the art and point out some limitations. We put a specific emphasis on cyanobacteria, as these microbes are considered future workhorses for photobiotechnology and are currently the most widely applied microbes in biophotovoltaics research. Current progress in biophotovoltaics is limited by very low current outputs of the devices while a lack of comparability and standardization of the experimental set-up hinders a systematic optimization of the systems. Nevertheless, the fundamental questions of redox homeostasis in photoautotrophs and the potential to directly harvest light energy from a highly efficient photosystem, rather than through oxidation of inefficiently produced biomass are highly relevant aspects of biophotovoltaics.

Novel Applications of Microbial Fuel Cells in Sensors and Biosensors

A microbial fuel cell (MFC) is a type of bio-electrochemical system with novel features, such as electricity generation, wastewater treatment, and biosensor applications. In recent years, progressive trends in MFC research on its chemical, electrochemical, and microbiological aspects has resulted in its noticeable applications in the field of sensing. This review was consequently aimed to provide an overview of the most interesting new applications of MFCs in sensors, such as providing the required electrical current and power for remote sensors (energy supply device for sensors) and detection of pollutants, biochemical oxygen demand (BOD), and specific DNA strands by MFCs without an external analytical device (self-powered biosensors). Moreover, in this review, procedures of MFC operation as a power supply for pH, temperature, and organic loading rate (OLR) sensors, and also self-powered biosensors of toxicity, pollutants, and BOD have been discussed.

Bibliometric analysis of global research trends on microbial fuel cells using Scopus database

The rising demand for sustainable energy and the availability of abundant wastes have stimulated research efforts around the world. As a newly emerging energy-based technology, microbial fuel cell (MFC) has received a significant attention due to its broad range of applications. Therefore, understanding the topics of interest and broadening collaboration networks are necessary to advance the research development towards integrated efforts. In this bibliometric study, our aim was to evaluate the global research trends in MFC area based on publication outputs, co-authorships among authors and affiliated countries, and co-occurrences of author keywords. Using the Scopus database, a total of 4126 journal articles published between 1962–2017 were retrieved. Results have shown that since 2008, the number of publications increased by 100 articles every two years, resulting in the steady increase in the cumulative total publications until present. About 60% of the global total publications were contributed by researchers from China and USA, leading the other 70 countries/territories. Also, among the most productive university from each of the 15 leading countries, four were amongst the world’s top 100 universities. In conclusion, recent progress in MFC research includes the following (but not limited to) (i) electrode materials incorporated nanotechnology, ceramic, and biochar; (ii) mathematical modeling (e.g. artificial neural network); and (iii) economic assessment and life cycle analysis.

Harvesting Energy using Biocatalysts

<i>Harvesting Energy using Biocatalysts</i>

(Invited) Limitations in Electrochemically Active Biofilms

Almost a decade has passed since the rediscovery of microbial fuel cell research, yet the power generation of these devices has not advanced. This is mainly due to the research being focused solely on the improvement of power generation rather than on a fundamental understanding of electron transfer processes and their limitations in the biofilms grown on the anode and cathode. The chemical and electrochemical gradients in these biofilms play a critical role in electron transfer rates between cells and a solid electron acceptor or donor. Our research group has developed and used novel microelectrodes and in situ Nuclear Magnetic Resonance (NMR) imaging techniques to investigate electron transfer mechanisms in biofilms. The newly developed microelectrodes were successfully operated on polarized surfaces. Both NMR and microelectrode technologies allowed us to quantify metabolic and chemical variations in biofilms while the cells respired on polarized electrode surfaces. We combined our techniques with two new techniques – rotating disk electrode (RDE) and electrochemical quartz crystal balance (eQCM). The addition of both these techniques allowed us to differentiate mass transfer limitations from intra-biofilm electron transfer processes. When we attempted to identify limitations in anodic biofilms, first, we addressed the importance of local acetate concentrations within G. sulfurreducens biofilms using a novel acetate microelectrode which has better resolution than NMR. The microelectrode work confirmed our previous NMR findings and generated profiles on the order of µM. We should note that the microelectrode method developed is significantly more economical to use than NMR and can facilitate rapid in situ measurements of acetate in anoxic biofilms. Second, we integrated our previous RDE method with our eQCM methods to show that, on both a per current basis and a per mass basis, biofilm capacitance is a better indicator of biofilm performance than conductance.In particular, we compared the capacitance/conductance relationship of G. sulfurreducens biofilms to those of both polyaniline films and diffusing flavin systems. The results indicated that the tandem increase in capacitance and conductance is unique to the extracellular electron transfer mechanisms operating in G. sulfurreducens biofilms. Our local potential and current measurements indicated that the upper layers of the biofilms are always under a reducing condition. This knowledge also confirmed that the amount of cytochromes in the biofilm is not high enough or the biofilm conductivity is not sufficient to generate an oxidizing condition near the top of a biofilm. Finally, we extended the role of excess surface area in the scale-up of bioelectrochemical systems by examining biomass accumulation under this condition. We found that biomass continues to accumulate on the excess surface area electrodes with net arithmetic growth rates and acetate consumption during steady-state current. The linear growth rates constrained by ion transport limitations that we found may be important factors in understanding the current generation using high-surface-area 3D electrodes with advection. In conclusion, we demonstrated the importance of the metabolic inactivity of layers within G. sulfurreducens biofilms using microelectrodes and NMR. In addition, we verified these findings using electrochemical impedance spectroscopy (EIS) by demonstrating the pseudocapacitive behavior of biofilm impedance. We also demonstrated the feasibility of directly measuring biofilm inefficiencies via intra-biofilm electron transfer rates and local current depth profiles.

A Review on Various Microbial Fuel Cells (MFCs) for Power Generation

The growing concerns for environment, health and monetary aspects have triggered a search for efficient and economic renewable sources of energy production. Microbial fuel cell (MFC) is an emerging technology that uses biofilms as catalysts to convert chemical energy in organic (and some inorganic) matters directly into electricity. MFC has a distinct advantage that is it can utilise low-grade biomass or even wastewater, which is otherwise not utilised, to produce bioelectricity. MFC research has intensified in the past decade, and the maximum MFC power density output has been increased greatly, and many types of waste streams have been tested. MFC power output is still much lower than that needed for practical power generation beyond powering small sensors, despite recent advances in reactor design.