Nevim Genç, Elif Durna

Pamukkale University Journal of Engineering Sciences • 2023

Energy recovery is an environmentally, economically and socially acceptable approach for the management of mucilage biomass. In this study, electricity generation potential of mucilage biomass by microbial fuel cell was evaluated. Mucilage biomass was used as electron donor substrate in the anode chamber and azo dye was used as electron acceptor in the cathode chamber. The maximum power density value (16.3 mW/m2) obtained in the raw mucilage is considerably lower than the power density (57.9 mV/m2) obtained from the mucilage biomass thermochemically pre-treated at high pressure and temperature. In the cathode chamber, over 87% azo dye removal was obtained. During operation under anaerobic conditions, an increase in soluble COD was observed with electron transfer due to the simultaneous continuation of dehydrogenation and biodegradation processes in the mucilage biomass.

Yong Jiang, Guoping Ren, Yifeng Zhang et al.

Energy &amp Environment Nexus • 2025

Amid rising global energy demands and mounting environmental challenges, the development of sustainable chemical synthesis technologies has become increasingly imperative. Biohybrid synthesis systems present a promising pathway by integrating abiotic materials capable of harnessing diverse energy sources—including direct current electricity, solar radiation, hydrovoltaic, and mechanical energy—to generate excited electrons that drive the metabolic activities of various biological components. This review first examines recent advances in microbial electrosynthesis (MES) technologies that utilize poised electrodes to replicate the activated abiotic materials capable to excite electrons. Special emphasis is placed on the structural limitations of biocathodes and innovations in formate-mediated electrocatalytic–biocatalytic tandem systems. Additionally, the review highlights progress in semi-artificial photosynthetic systems that utilize whole cells to directly capture solar energy for the biosynthesis of value-added chemicals. Emerging frontiers in biohybrid design are also explored, with a focus on the incorporation of hydrovoltaic and piezoelectric materials. The review further underscores the critical importance of understanding the interactions between abiotic materials and microbial systems, and discusses the potential of alternative energy modalities for constructing biohybrids, along with their applications in diverse environmental contexts. In conclusion, this work offers timely insights into cutting-edge technologies at the intersection of energy and environmental science, contributing to the advancement of sustainable chemical synthesis for a more resilient future.

Alicia A. Mier, Ruth Belinda Domínguez-Espíndola, Hugo Olvera‐Vargas et al.

BioEnergy Research • 2025

Abstract This study evaluated the potential of mixed microalgae-bacteria cultures as electroactive microorganisms to enhance electricity production while simultaneously treating wastewater in emerging biophotovoltaic (BPV) systems. Graphite felt decorated with TiO₂ nanotubes (TiO₂-NTs) was used as the anode, supporting the growth of a biofilm composed of mixed microalgae-bacterial cultures. Batch BPV reactors treated real domestic-industrial wastewater and were compared with BPV systems using bare graphite felt anodes, both with and without microalgae-bacteria cultures. All BPVs operated under a 12-h light/dark cycle, with continuous current monitoring and water quality assessments performed at the beginning and end of the experiments. The TiO₂-NT BPV exhibited the highest power output, reaching 2.37 mW/m 2 . BPVs with bare graphite felt anodes achieved power densities of 1.48 mW/m 2 and 0.41 mW/m 2 with and without microalgae, respectively. Systems inoculated with microalgae-bacteria cultures also showed lower ohmic losses, reaching open circuit voltages between 0.125 and 0.130 V, whereas systems without microalgae reached only 0.050 V and exhibited faster potential drops. In terms of wastewater treatment, TiO₂-NT BPVs achieved the highest removal efficiencies for chemical oxygen demand (COD) and nitrogen, exceeding 90% COD removal and over 80% removal of total ammoniacal nitrogen and nitrate. This study demonstrates that integrating mixed microalgae-bacteria cultures with TiO₂ nanostructured anodes in multifunctional BPV systems significantly enhances both wastewater treatment performance and power generation.

Veera Gnaneswar Gude, Bahareh Kokabian

Proceedings of The 1st International Electronic Conference on Water Sciences • 2016

Microbial desalination cells (MDCs), a recent technological discovery, allow for simultaneous wastewater treatment and desalination of saline water with concurrent electricity production. The premise for MDC performance is based on the principles that bioelectrochemical (BES) systems convert wastewaters into treated effluents accompanied by electricity production and the ionic species migration (i.e. protons) within the system facilitates desalination. One major drawback with microbial desalination cells (MDCs) technology is its unsustainable cathode chamber where expensive catalysts and toxic chemicals are employed for electricity generation. Introducing biological cathodes may enhance the system performance in an environmentally-sustainable manner. This study describes the use of autothrophic microorganism such as algae and Anammox bacteria as sustainable biocatalyst/biocathode in MDCs. Three different process configurations of photosynthetic MDCs (using Chlorella vulgaris) were evaluated for their performance and energy generation potentials. Static (fed-batch, SPMDC), continuous flow (CFPMDC) and a photobioreactor MDC (PBMDC, resembling lagoon type PMDCs) were developed to study the impact of process design on wastewater treatment, electricity generation, nutrient removal, and biomass production and the results indicate that PMDCs can be configured with the aim of maximizing the energy recovery through either biomass production or bioelectricity production. In addition, the microbial community analysis of seven different samples from different parts of the anode chamber, disclosed considerable spatial diversity in microbial communities which is a critical factor in sustaining the operation of MDCs. This study provides the first proof of concept that anammox mechanism can be beneficial in enhancing the sustainability of microbial desalination cells to provide simultaneous removal of ammonium from wastewater and contribute in energy generation.

Manman Li

Journal of Energy Bioscience • 2024

Microbial fuel cell (MFC) is a potential technology that combines pollution reduction and renewable energy generation in wastewater treatment. Microbial fuel cell (MFC) technology, as an innovative solution for achieving pollutant degradation and renewable energy production in wastewater treatment, has received widespread attention in recent years. This study explores the principles, mechanisms, and applications of MFC in wastewater treatment. Through case studies of industrial wastewater, the practical application and energy recovery potential of MFC are demonstrated, and its performance is compared with traditional methods. By optimizing and promoting MFC technology, this study expects to improve the energy efficiency of wastewater treatment, achieve environmental sustainability, and provide policy support recommendations.

Yongxin Liu, Ailing Xu, Chao Liu et al.

Aquaculture Research • 2023

Chlorella pyrenoidosa is a widely used microalgae in the aquaculture process of Litopenaeus vannamei. In order to evaluate the effects of supplementing C. pyrenoidosa on water quality, shrimp growth performance, and biofilm bacterial community structure in L. vannamei aquaculture systems, C. pyrenoidosa suspension was supplemented in the precultured biofilm (PB) and water exchange (WE) culture systems. The results showed that supplementation with C. pyrenoidosa significantly increased the turbidity and the concentrations of total ammonia nitrogen (TAN) and nitrite nitrogen ( NO 2 − ─N) in the PBC system (the PB system supplemented with C. pyrenoidosa), but had no significant effect on those in the WEC system (the WE system supplemented with C. pyrenoidosa). However, the TAN concentration of all systems remained at a low level (<0.1 mg/L) throughout the experiment. Additionally, supplementation with C. pyrenoidosa decreased the final concentrations of total phosphorus in the PBC and WEC systems by 15.74% and 23.33%, respectively. With the supplementation of C. pyrenoidosa, the final weight, final biomass, and average daily growth rate of L. vannamei increased, while the feed conversion ratio decreased. 16srRNA high-throughput sequencing results showed that the supplementation of C. pyrenoidosa to the PBC system resulted in a decrease in the relative abundances of Proteobacteria and Bacteroidetes and an increase in the relative abundance of Acidobacteria. Compared to those in the initial biofilm sample, the relative abundances of nitrifying bacteria, Nitrosococcus, Nitrosomonas, Nitrococcus, and Nitrospira, in PBCF (biofilm in the PB systems with C. pyrenoidosa) and PBOF (biofilm in the PB systems without C. pyrenoidosa) decreased from 10.18% to 3.05% and 0.75%, respectively. In conclusion, C. pyrenoidosa, as a supplement to the aquaculture systems, has practical application prospects.

Segundo Rojas-Flores, Rafael Liza, Renny Nazario-Naveda et al.

Processes • 2025

This study presents a bibliometric review of scientific progress concerning the synergy between microbial fuel cells (MFCs) and textile dye remediation. Drawing from the Scopus database, the analysis spans the years 2005–2025 and applies systematic filters to derive a final corpus of 239 articles compatible with Bibliometrix software (4.2.1). Quantitative and structural analyses were conducted using RStudio with the Bibliometrix package, thematic network visualizations via VOSviewer (1.6.19), and frequency matrices, citation rates, and international collaboration indicators organized in Excel. Results reveal exponential growth in scholarly output, particularly within Environmental Sciences, Chemical Engineering, and Microbiology. China and India lead in publication volume, while countries such as the United Kingdom, United States, and Australia show high impact and international collaboration. Co-authorship networks reflect consolidated clusters, though connectivity gaps remain among emerging authors. Bioresource Technology is identified as a central journal, with terms like “wastewater treatment” and “microbial fuel cell” indicating thematic consolidation. Opportunities still exist in areas such as explainable artificial intelligence, integration with microalgae, and heavy metal remediation. Highly cited articles contribute key technical insights, highlighting hybrid configurations and advancements in electrode materials. Strategic mapping suggests that MFCs have evolved from experimental concepts to viable alternatives in industrial sustainability, though scalability, operational costs, and geographic representation remain significant challenges. This bibliometric review not only maps accumulated knowledge but also serves as a strategic compass for guiding future research toward integrated, accessible, and replicable bioelectrochemical technologies for textile dye treatment.

Hayder A. Waheeb, Ahmed Faiq Al-Alawy

Egyptian Journal of Chemistry • 2021

In this work, microbial fuel cell (MFC) design of five chambers was used to investigate the effect of four types of membranes which are cation exchange membrane (CEM), Cellulose Triacetate membrane (CTA), thin film composite membrane (TFC), and proton exchange membrane (PEM). To study the influence of the membrane type on the cathode performance, the four cathode chambers were filled with 20 g/l NaCl catholyte and the sodium acetate of 1.5 g/l was supplied to the central chamber as anolyte. The results revealed that the membrane proton selectivity plays an important role in the cathodic reduction reaction for electrical generation and water production. It was observed that the PEM has a significant effect on the power generation with a maximum power density of 20.492 mW/m2 with water production of 4.21 g/day. Whereas the competition of the other cations to the proton transfer was clearly observed by using the CTA membrane with power production of 12.646 mW/m2, and the abundance of the water production of 178.16 g/day was attributed to the water transport across the CTA membrane. For studying the influence of the membrane type on the anode performance, the sodium acetate of 1.5 g/l was supplied to the four chambers as an anolyte at a flow rate of 0.0272 cm3/sec and the central chamber were filled with 20 g/l NaCl catholyte. The salt reverse transfer from the cathode chamber to the anode chamber across the CTA membrane contributed to increasing the anolyte electrical conductivity and consequently increased the power production to 12.555 mW/m2. Meanwhile, the effect of the proton selectivity and the electrical resistance of the other membrane were observed in the other chambers. Thus, the usage of CEM, TFC, and PEM produced electrical power of 6.751, 3.004, and 9.712 mW/m2 respectively.

Chetan Pandit, Siddhant Srivastava, Chang‐Tang Chang

Catalysts • 2025

Biohydrogen, a low-carbon footprint technology, can play a significant role in decarbonizing the energy system. It uses existing infrastructure, is easily transportable, and produces no greenhouse gas emissions. Four technologies can be used to produce biohydrogen: photosynthetic biohydrogen, dark fermentation (DF), photo-fermentation, and microbial electrolysis cells (MECs). DF produces more biohydrogen and is flexible with organic substrates, making it a sustainable method of waste repurposing. However, low achievable biohydrogen yields are a common issue. To overcome this, catalytic mechanisms, including enzymatic systems such as [Fe-Fe]- and [Ni-Fe]-hydrogenases in DF and electroactive microbial consortia in MECs, alongside advanced electrode catalysts which collectively surmount thermodynamic and kinetic constraints, and the two stage system, such as DF connection to photo-fermentation and anaerobic digestion (AD) to microbial electrolysis cells (MECs), have been investigated. MECs can generate biohydrogen at better yields by using sugars or organic acids, and combining DF and MEC technologies could improve biohydrogen production. As such, this review highlights the challenges and possible solutions for coupling DF–MEC while also offering knowledge regarding the technical and microbiological aspects.

Jinlong Li, Xiaowei Wang, Shihai Deng et al.

Water • 2024

Iron–carbon galvanic-cell-supported autotrophic denitrification (IC-ADN) is a burgeoning efficient and cost-effective process for low-carbon wastewater treatment. This study revealed the influence of organic carbon (OC) and dissolved oxygen (DO) on IC-ADN in terms of functional and microbiological characteristics. The nitrogen removal efficiency increased to 91.6% and 94.7% with partial organic carbon source addition to COD/TN of 1 and 3, respectively. The results of 16S rRNA high-throughput sequencing with nirS and cbbL clone libraries showed that Thiobacillus was the predominant autotrophic denitrifying bacteria (ADB) in the micro-electrolysis-based autotrophic denitrification, which obtained nitrogen removal efficiency of 80.9% after 96 h. The ADBs shifted gradually to heterotrophic denitrifying bacteria Thauera with increasing COD/TN ratio. DO concentration of 0.8 rarely affected the denitrification efficiency and the denitrifying communities. When the DO concentration increased to 2.8 mg/L, the nitrogen removal efficiency decreased to 69.1%. These results demonstrated that autotrophic denitrification was notably affected by COD/TN and high DO concentration, which could be used to acquire optimum conditions for nitrogen removal. These results provided an in-depth understanding of the influential factors for galvanic-cell-based denitrification and helped us construct a stable and highly efficient treatment process for insufficient carbon source wastewater.

Emna Mhedhbi, Paola Foladori, Issam Smaali

Euro-Mediterranean Journal for Environmental Integration • 2025

Musa Bishir, Catalina Rodríguez Correa, Maciej P. Olszewski et al.

International Journal of Biomass and Renewables • 2023

Microbial Fuel Cell (MFC) is a dual-edged technology which combines wastewater treatment with power generation. The chemical energy present in the organic matter of wastewater is usually transformed into electricity in MFCs through the action of electroactive bacteria on electrodes which act as catalysts. The MFC technology has piqued the interest of numerous researchers since it has the unique capability for wastewater treatment while concurrently generating some bioelectricity. When compared with traditional energy sources, MFCs have various advantages over other wastewater treatment processes, such as the trickling filter method and the commonly employed activated sludge process. These advantages include but are not limited to low energy requirements, low or no production of hazardous products, and mild reaction conditions. As a result, this wastewater treatment process is both cost-effective and long-term. The various designs of MFCs, electrode materials, and various wastewaters (substrates) that electrogenic bacteria could utilize are discussed in this work. The review gave succinct information on the components of microbial fuel cells, their operations as well as the stability and sustainability of the fuel cell systems Keywords: microbial fuel cell, wastewater, substrate, electrodes, electroactive bacteria, bioelectricity

A. Yağmur Gören, Hatice Eser Ökten

Desalination • 2022

Segundo Rojas-Flores, Magaly De La Cruz-Noriega, Luis Cabanillas-Chirinos et al.

Fermentation • 2024

Currently, industry in all its forms is vital for the human population because it provides the services and goods necessary to live. However, this process also pollutes soils and rivers. This research provides an environmentally friendly solution for the generation of electrical energy and the bioremediation of heavy metals such as arsenic, iron, and copper present in river waters used to irrigate farmers’ crops. This research used single-chamber microbial fuel cells with activated carbon and zinc electrodes as anodes and cathodes, respectively, and farmers’ irrigation water contaminated with mining waste as substrate. Pseudomonas stutzeri was used as a biocatalyst due to its ability to proliferate at temperatures between 4 and 44 °C—at which the waters that feed irrigated rivers pass on their way to the sea—managing to generate peaks of electric current and voltage of 4.35 mA and 0.91 V on the sixth day, which operated with an electrical conductivity of 222 mS/cm and a pH of 6.74. Likewise, the parameters of nitrogen, total organic carbon, carbon lost on the ignition, dissolved organic carbon, and chemical oxygen demand were reduced by 51.19%, 79.92%, 64.95%, 79.89%, 79.93%, and 86.46%. At the same time, iron, copper, and arsenic values decreased by 84.625, 14.533, and 90.831%, respectively. The internal resistance values shown were 26.355 ± 4.528 Ω with a power density of 422.054 mW/cm2 with a current density of 5.766 A/cm2. This research gives society, governments, and private companies an economical and easily scalable prototype capable of simultaneously generating electrical energy and removing heavy metals.

Abhijeet Das, Satchidananda Mishra

Green Technology Resilience and Sustainability • 2025

The improper management of wastewater, leading to its contamination of clean water sources, results in water pollution, ecological degradation, and significant health hazards. Addressing these challenges requires the removal of pollutants from wastewater streams and their reintegration into the water cycle to protect environmental health and public well-being. However, the goal is not merely to eliminate pollutants but to repurpose them as valuable resources, aligning with the principles of sustainability. Concurrently, the rising demand for energy and the depletion of conventional resources necessitates the adoption of renewable alternatives. Microbial fuel cells (MFCs) represent an innovative solution, enabling the conversion of organic compounds in wastewater into electrical energy while simultaneously producing clean water. Despite their potential, MFCs face significant challenges related to scalability and technical limitations that hinder their widespread application. To enhance the practicality of MFCs, it is crucial to investigate the parameters influencing their performance and explore advancements in areas such as electrode materials, microbial communities, and operational conditions. This study aims to evaluate the constraints on MFC performance and efficiency in the dual roles of sustainable energy generation and wastewater treatment. It further seeks to propose innovative approaches to support the real-world implementation of MFCs as a cornerstone technology for promoting a circular economy and advancing global sustainability goals. • Clean Water Generation: Microbial Fuel Cells (MFCs) treat wastewater while simultaneously producing electricity. • Renewable Energy Source: MFCs harness bioenergy from organic waste using microbial metabolism. • Circular Economy Integration: MFCs promote resource recovery—clean water, energy, and nutrients—from waste streams. • Sustainability Potential: They offer low-carbon, decentralized solutions for water-energy nexus challenges.

Tahereh Jafary, Ali Mousavi, Anteneh Mesfin Yeneneh et al.

Sustainability • 2026

Microbial fuel cells (MFCs) are a promising technology for simultaneously treating wastewater and recovering energy, yet scaling them from lab prototypes to practical systems poses persistent challenges. This review addresses the scale-up gap by systematically examining recent pilot-scale MFC studies from multiple perspectives, including reactor design configurations, materials innovations, treatment performance, energy recovery, and environmental impact. The findings show that pilot MFCs reliably achieve significant chemical oxygen demand (COD) removal (often 50–90%), but power densities remain modest (typically 0.1–10 W m−3)—far below levels needed for major energy generation. Key engineering advances have improved performance; modular stacking maintains higher power output, low-cost electrodes and membranes reduce costs (with some efficiency trade-offs), and power-management strategies mitigate issues like cell reversal. Life cycle assessments indicate that while MFC systems can outperform conventional treatment in specific scenarios, overall sustainability gains depend on boosting energy yields and optimizing materials. The findings highlight common trade-offs and emerging strategies. By consolidating recent insights, a roadmap of design principles and research directions to advance MFC technology toward sustainable, energy-positive wastewater treatment was outlined.

Kun Tang, Suxuan Li, Yijing Luo et al.

RSC Advances • 2025

Microbial Fuel Cells (MFC) are an emerging biomass energy technology that harnesses the power of electroactive bacteria living on a bacterial biofilm to convert biomass energy within waste materials into usable electricity. A pivotal aspect of MFC research involves understanding the behavior and underlying mechanisms of electroactive bacteria during extracellular electron transfer to the anode, which plays a crucial role in energy conversion. In this paper, four MFCs were operated at external resistances of 500 and 1000 ohms, and the changes in the biofilm's electroactive bacterial composition due to altered external resistances were indicated by the voltage and power differences. After stable power generation, total DNA was extracted from the biofilm for sequencing, and metabolites were tested. The expression trends of genes and the differences in final metabolites from the whole period indicate that electron transfer gene families are associated with Shewanella , Pseudomonas , Trichococcus , and Enterococcus , while tyrosine and purine metabolism showed significant differences in effective metabolite accumulation among communities with varying energy output efficiency. Omics techniques revealed, to some extent, the coordination mechanisms and bacterial interactions within biofilms during microbial community succession.

Mithra Geetha, Kishor Kumar Sadasivuni, Maryam Al‐Ejji et al.

Current Biotechnology • 2022

Abstract: Energy generation from renewable sources and effective management are two critical challenges for sustainable development. Biofuel Cells (BFCs) provide an elegant solution by com-bining these two tasks. BFCs are defined by the catalyst used in the fuel cell and can directly gener-ate electricity from biological substances. Various nontoxic chemical fuels, such as glucose, lactate, urate, alcohol, amines, starch, and fructose, can be used in BFCs and have specific components to oxide fuels. Widely available fuel sources and moderate operational conditions make them promise in renewable energy generation, remote device power sources, etc. Enzymatic biofuel cells (EBFCs) use enzymes as a catalyst to oxidize the fuel rather than precious metals. The shortcoming of the EBFCs system leads to integrated miniaturization issues, lower power density, poor operational sta-bility, lower voltage output, lower energy density, inadequate durability, instability in the long-term application, and incomplete fuel oxidation. This necessitates the development of non-enzymatic bio-fuel cells (NEBFCs). The review paper extensively studies NEBFCs and its various synthetic strat-egies and catalytic characteristics. This paper reviews the use of nanocomposites as biocatalysts in biofuel cells and the principle of biofuel cells as well as their construction elements. This review briefly presents recent technologies developed to improve the biocatalytic properties, biocompatibil-ity, biodegradability, implantability, and mechanical flexibility of BFCs.

B. Senthil Rathi, P. Senthil Kumar, VA Parthasarathy et al.

Water Practice & Technology • 2024

ABSTRACT Hazardous pollutants include a variety of pollutants, including emerging contaminants (ECs), organic pollutants, inorganic pollutants, and heavy metals. Scientists have lately become interested in ECs in effluent because they represent serious hazards to both biodiversity and human health even at low concentrations. For the elimination of different ECs, several treatment technologies, including chemical-based, physical-based, and biological-based methods, have been developed. Nonetheless, no one technique can presently efficiently eradicate ECs; biological treatments are frequently found to be more beneficial. This review aims to give a brief analysis of the sources, kinds, impacts, and monitoring and detection techniques for ECs. This review provides information on such biological processes for the quick and eco-friendly removal methods of ECs from effluent. The article highlights the methodology used by the hybrid system to eliminate distinct EC types. The hybrid structure of a membrane bioreactor (MBR) accompanied by filtrations using membrane successfully got rid of a bunch of ECs. For the biosorptive elimination of pharmaceuticals various hybrid structures comprising constructed wetlands (CWs) and waste stabilization ponds demonstrated amazing possibilities. Future directions of study for the elimination of ECs using green, sustainable technologies and hybrid techniques have been proposed.

Sourabh Chakraborty, Nurhan Turgut Dunford

Biomass • 2024

Microalgae-based renewable energy, industrial chemicals, and food have received great attention during the last decade. This review article highlights the versatility of algal biomass as a feedstock for producing various commodities and high-value products, including aromatic hydrocarbons and lipids within biorefinery systems. Lipid content and the composition of algal biomass cultivated in various media, specifically in wastewater streams generated at agricultural and industrial production facilities, are reviewed. Technical and chemical aspects of algal biomass conversion via thermochemical techniques including pyrolysis, hydrothermal liquefaction, and hydrothermal carbonization are discussed. The properties of the final products are reviewed based on the conversion process employed. Studies published within the last 5 years are reviewed. The importance of further research on inexpensive and more effective catalysts and the development of downstream processes to upgrade crude products obtained from thermal conversion processes is emphasized. This review concludes with an in-depth discussion of the opportunities and challenges involved in algal biomass-based bioproduct manufacturing and commercialization.

Segundo Rojas-Flores, Magaly De La Cruz-Noriega, Luis Cabanillas-Chirinos et al.

Sustainability • 2024

Currently, two significant problems involve the government, population, and environment: the accelerated increase in organic waste and the need to replace conventional energy with environmentally sustainable energy. The sustainable use of organic waste is being intensely investigated to generate energy plants that produce alternative sustainable electrical energy beneficial to the population at a low cost. The novelty of this research is given by the use of pepper waste as fuel in the generation of bioelectricity, giving added value to these types of waste, benefiting farmers and companies dedicated to the export and import of these fruits, because they will be able to generate their own electrical energy using their own waste at a lower cost. For this reason, this research uses pepper waste as fuel in single-chamber microbial fuel cells manufactured at a low cost as its primary objective. The maximum values of the electric current (5.118 ± 0.065 mA) and electric potential (1.018 ± 0.101 V) were shown on the fourteenth day, with an optimal operating pH of 7.141 ± 0.134 and electrical conductivity of 112.846 ± 4.888 mS/cm. Likewise, a reduction in the COD was observed from 1210.15 ± 0.89 mg/L to 190.36 ± 16.58 mg/L in the 35 days of monitoring and with a maximum ORP of 426.995 ± 8.615 mV, whose internal resistance was 33.541 ± 2.471 Ω. The peak power density was 154.142 ± 8.151 mW/cm2 at a current density of 4.834 A/cm2, and the Rossellomorea marisflavi strain was identified with 99.57% identity.

Veera Gnaneswar Gude

Journal of Water Supply Research and Technology—AQUA • 2021

Abstract This article presents the evolving challenges and roles of our water resources in this contemporary world. First, water quality issues surrounding water supplies are discussed. Potential pathways to address the water quality challenges are presented, which include technological approaches for minimizing waste and enhancing resource recovery. Focused discussions on emerging global pollutants such as microplastics and PFAS (per- and poly-fluoro alkyl substances) and treatment alternatives are included. Next, the roles of used water (wastewater) in the wake of circular economy and recent outbreaks are discussed. The potential for energy and resource recovery possibilities and the critical role of wastewater treatment plants in controlling the spread of outbreaks are discussed in detail. Finally, perspectives on some of the key developments essential for transforming our water infrastructure, addressing water-centered socio-economic issues and the critical needs of digitalization in water sector operations are presented.

Rui N. L. Carvalho, Luísa Monteiro, Sílvia A. Sousa et al.

Energies • 2023

The increased demand for alternative sustainable energy sources has boosted research in the field of fuel cells (FC). Among these, microbial fuel cells (MFC), based on microbial anodes and different types of cathodes, have been the subject of renewed interest due to their ability to simultaneously perform wastewater treatment and bioelectricity generation. Several different MFCs have been proposed in this work using different conditions and configurations, namely cathode materials, membranes, external resistances, and microbial composition, among other factors. This work reports the design and optimization of MFC performance and evaluates a hydrogel (Ion Jelly®) modified air-breathing cathode, with and without an immobilized laccase enzyme. This MFC configuration was also compared with other MFC configuration performances, namely abiotic and biocathodes, concerning wastewater treatment and electricity generation. Similar efficiencies in COD reduction, voltage (375 mV), PD (48 mW/m2), CD (130 mA/m2), and OCP (534 mV) were obtained. The results point out the important role of Ion Jelly® in improving the MFC air-breathing cathode performance as it has the advantage that its electroconductivity properties can be designed before modifying the cathode electrodes. The biofilm on MFC anodic electrodes presented a lower microbial diversity than the wastewater treatment effluent used as inocula, and inclusively Geobacteracea was also identified due to the high microbial selective niches constituted by MFC systems.

Priya Pilania, K. G. Bhushan, Urmila Gupta Phutela

Fermentation • 2025

Electro-fermentation (EF) is an emerging bioprocess with the ability to regulate the metabolism of electrochemically active microorganisms. In various fermentation processes, electrodes perform either as an electron acceptor or donor, facilitating the formation and movement of electrons and protons. The bioelectric activity created by external electrodes enhances the metabolic reactions, resulting in a higher yield of value-added chemicals. The conventional fermentation process has a number of limitations in terms of usability and economic feasibility, whereas electro-fermentation presents a hybrid technology, minimizing redox instabilities and enhancing the metabolic process in general to achieve increased product production and a higher biomass yield. Electrochemically active microorganisms such as Geobacter and Shewanella species can carry out the exchange of electrons with electrodes directly or indirectly by using electron mediators. Furthermore, the integration of microbial fuel cells (MFCs) with microbial electrolysis cells (MECs) precludes the need for external manipulation of the fermentation system as the required change in electrochemical gradient is provided by the MFC counterpart. The major beneficial aspects of electro-fermentation include its role as a potential tool for enhancing the production of value-added compounds. The mixed-culture system clearly had a favorable impact on the synthesis of butyric acid from rice straw. Furthermore, cathodic electro-fermentation (CEF) exhibited benefits over anaerobic fermentation, influencing NADH/NAD+, enabling a higher product titer, and reducing the accumulation of byproducts. Hence, in this review, we emphasize the importance of electro-fermentation over conventional fermentation for biofuel and biochemical production, covering its fundamentals, interactions, types, future challenges, and ability to provide several benefits to boost the fermentation process, such as the process efficiency and product yield, on an industrial scale.

Md. Al Sadikul Islam, Tanveer Saeed, Nehreen Majed

Frontiers in Environmental Science • 2022

One of the most persistent issues affecting individuals in developing countries is the lack of access to safe drinking water and sanitary facilities. The adoption of centralized water, energy, and cost-intensive technology has proven ineffective in addressing the complex water-related challenges that have arisen as a consequence of growing urbanization in developing nations. Constructed wetlands have emerged as an effective wastewater treatment solution with natural applications. The fundamental goal of this study is to offer a complete overview of the wide variety of practices, uses, and investigations of constructed wetlands systems for eliminating different pollutants from wastewater in developing countries leading to placing them in the context of climate change, environmental resource planning, and sustainable wastewater treatment systems. CWs offer significant levels of treatment performances with hybrid systems achieving contaminant removal efficiencies up to 93.82% for total suspended solids, 85.65% for chemical oxygen demand, and 80.11% for ammonia nitrogen which is adequate with respect to other viable alternatives. In terms of Biological Oxygen Demand (BOD 5 ), the highest elimination (84.06%) was achieved in hybrid systems when compared to Free water surface CWs (65.34%), Horizontal sub-surface CWs (75.1%), and Floating treatment wetland (55.29%). The maximum power density generation through the microbial fuel cell-based constructed wetlands ranges between 50 and 86 mW/m 2 in Bangladesh (integrated tidal flow) and 852 mW/m 3 in China (vertical flow), and the production of bioenergy has been evidenced up to 1,836.5 GJ/hector/year. Annually, wastewater treatment plant systems (WTPs) generate around a hundred times more Methane (CH 4 ), Nitrous oxide (N 2 O), and carbon dioxide (CO 2 ) than CWs. In metropolitan cities, WTPs may lead to a considerable increase in upstream land use, which could be minimized by promoting CWs in these areas. The potential utility of different CWs in protecting and preserving estuarine quality within the present regulatory framework is finally addressed in the study, emphasizing that it can balance the impacts of industrial expansions in developing countries for subsequent mitigation and adaptation to climate change.

Sili Qing, Linlin Wang, Liping Jiang et al.

SmartMat • 2022

Abstract Electrochemical oxygen reduced reaction (ORR) is a critical element in clean energy development. Despite efforts to enhance gas transfer to the reaction interface, the low solubility of O 2 molecules and slow diffusion rate in liquid electrolyte is still a significant challenge. Herein, we design an artificial outer membrane on microalgal cells, which consists of a carbon dots/bilirubin oxidase (CDs/BOD) ORR catalyst layer and a L‐cystine/Au nanoporous O 2 supply layer. O 2 generated by photosynthesis from microalgal cells then can be directly transported to the CDs/BOD catalytic interfaces, overcoming the sluggish gas transfer in the electrolyte. Thus, the cathode constructed by the fabricated microalgal cells realizes an ORR current density of 655.2 μA/cm 2 with fast ORR kinetics, which is 2.68 times higher than that of a BOD cathode fed with pure O 2 . A membrane‐less glucose/O 2 biofuel cell is further developed using the hybrid artificial cells as the cathode, and the power density is 2.39 times higher than that of a BOD cathode biofuel cell in O 2 saturated solution. This biomimetic design supplies O 2 directly to the carbon dots/BOD catalyst layer from the microalgae membrane through a nanoporous L‐cys/Au layer, providing an alternative solution for the transfer barrier of O 2 in the electrolyte.

Pimprapa Chaijak, Panisa Michu

Polish Journal of Environmental Studies • 2022

The biochar electrode is an alternative low-cost electrode for electricity generation and wastewater treatment by the microbial fuel cell (MFC). In this study, the water hyacinth biochar (WHB) was prepared by pyrolysis at 350C and activated by chemical immersion. The activated WHB was integrated with ceramic-separator MFC (CMFC) and used for the pharmaceutical wastewater (containing 100 g/mL penicillin) treatment and electricity generation. The maximal power output and penicillin removal of 0.0320.001 W/m 2 and 65.120.02% were achieved. This study gained new knowledge of using the WHB electrode coupled with the CMFC for pharmaceutical wastewater treatment and electricity generation.

Abdelghani Ghanam, Sébastien Cecillon, Andreï Sabac et al.

Micromachines • 2023

This research sought to enhance the efficiency and biocompatibility of anodes in bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs), with an aim toward large-scale, real-world applications. The study focused on the effects of acid-heat treatment and chemical modification of three-dimensional porous pristine carbon felt (CF) on power generation. Different treatments were applied to the pristine CF, including coating with carbon nanofibers (CNFs) dispersed using dodecylbenzene sulfonate (SDBS) surfactant and biopolymer chitosan (CS). These processes were expected to improve the hydrophilicity, reduce the internal resistance, and increase the electrochemically active surface area of CF anodes. A high-resolution scanning electron microscopy (HR-SEM) analysis confirmed successful CNF coating. An electrochemical analysis showed improved conductivity and charge transfer toward [Fe(CN)6] 3-/4- redox probe with treated anodes. When used in an air cathode single-chamber MFC system, the untreated CF facilitated quicker electroactive biofilm growth and reached a maximum power output density of 3.4 W m -2 , with an open-circuit potential of 550 mV. Despite a reduction in charge transfer resistance (R ct ) with the treated CF anodes, the power densities remained unchanged. These results suggest that untreated CF anodes could be most promising for enhancing power output in BESs, offering a cost-effective solution for large-scale MFC applications.

Abreham Tesfaye Besha, Misgina Tilahun Tsehaye, Girum Ayalneh Tiruye et al.

Sustainability • 2020

Membrane-based energy technologies are presently gaining huge interest due to the fundamental engineering and potentially broad range of applications, with economic advantages over some of the competing technologies. Herein, we assess the potential deployability of the existing and emerging membrane-based energy technologies (MEnT) in Ethiopia. First, the status of the current energy technologies is provided along with the active energy and environmental policies to shape the necessary research strategies for technology planning and implementation. Ethiopia is a landlocked country, which limits the effective extraction of energy, for instance, from seawater using alternative, clean technologies such as reverse electrodialysis and pressure retarded osmosis. However, there exists an excess off-grid solar power (up to 5 MW) and wind which can be used to drive water electrolyzers for hydrogen production. Hydrogen is a versatile energy carrier that, for instance, can be used in fuel cells providing zero-emission solutions for transport and mobility. Although Ethiopia is not among the largest CO2 emitters, with more than 90% energy supply obtained from waste and biomass, the economic and industrial growth still calls for alternative CO2 capture and use technologies, which are highlighted in this work. We believe that the present work provides (i) the status and potential for the implementation of MEnT in Ethiopia (ii) and basic guidance for researchers exploring new energy pathways toward sustainable development in developing countries.

Walter Rojas-Villacorta, Segundo Rojas-Flores, Santiago M. Benites et al.

Energy Reports • 2023

The research aimed to generate bioelectricity using pepper waste and the microalgae Spirulina sp by a double-chamber microbial fuel cell (dcMFC). A dcMFC was constructed with Cu and Zn electrodes, where organic waste and microalgae were placed in the anodic and cathodic chambers, respectively. Also, electrochemical parameters were measured for 35 days. Finally, possible electrogenic microorganisms were isolated and identified. It was possible to generate maximum values of current (6.04414 ± 0.2145 mA) and voltage (0.77328 ± 0.213 V). The maximum conductivity value was 134.1636 ± 7.121 mS/cm, while the internal resistance value was 83.784 ±7.147Ω. The values of power and current density reached were 584.45 ± 19.14 mW/cm 2 and 5.983 A/cm 2, respectively. The optimal operating pH was 4.59 ± 0.14. From the microbial growth on the anode, the yeast Yarrowia phangngaensis (1) and Pseudomonas stutzeri (2) were identified, which may be involved in the transfer of electrons to the electrode. In conclusion, it was possible to generate clean energy in a laboratory-scale dcMFC when pepper waste and Spirulina sp. were used. These results are promising because organic waste can generate sustainable and environmentally friendly energy.

П. М. Готовцев, Vitaly Vorobiev, A. S. Migalev et al.

Robotics • 2018

This paper presents the problem of application of modern developments in the field of bio-energy for the development of autonomous mobile robots’ power sources. We carried out analysis of biofuel cells, gasification and pyrolysis of biomass. Nowadays, very few technologies in the bioenergy field are conducted with regards to the demands brought by robotics. At the same time, a number of technologies, such as biofuel cells, have now already come into use as a power supply for experimental autonomous mobile robots. The general directions for research that may help to increase the efficiency of power energy sources described in the article, in case of their use in robotics, are also presented.

K. Elangovan, Prabhu Saravanan, Cristian H. Campos et al.

Frontiers in Chemical Engineering • 2023

The microbial fuel cells (MFCs) which demonstrates simultaneous production of electricity and wastewater treatment have been considered as one of the potential and greener energy production technology among the available bioelectrochemical systems. The air-cathode MFCs have gained additional benefits due to using air and avoiding any chemical substances as catholyte in the cathode chamber. The sluggish oxygen reduction reaction (ORR) kinetics at the cathode is one of the main obstacles to achieve high microbial fuel cell (MFC) performances. Platinum (Pt) is one of the most widely used efficient ORR electrocatalysts due to its high efficient and more stable in acidic media. Because of the high cost and easily poisoned nature of Pt, several attempts, such as a combination of Pt with other materials, and using non-precious metals and non-metals based electrocatalysts has been demonstrated. However, the efficient practical application of the MFC technology is not yet achieved mainly due to the slow ORR. Therefore, the review which draws attention to develop and choosing the suitable cathode materials should be urgent for the practical applications of the MFCs. In this review article, we present an overview of the present MFC technology, then some significant advancements of ORR electrocatalysts such as precious metals-based catalysts (very briefly), non-precious metals-based, non-metals and carbon-based, and biocatalysts with some significant remarks on the corresponding results for the MFC applications. Lastly, we also discussed the challenges and prospects of ORR electrocatalysts for the practical application of MFCs.

V.M. Ortiz-Martínez, Khaled Touati, M.J. Salar-García et al.

Biochemical Engineering Journal • 2019

Rojas-Flores Segundo, Magaly De La Cruz-Noriega, Renny Nazario-Naveda et al.

Fermentation • 2022

The environmental problems caused by the excessive use of fossil fuels for electricity generation have led to the development of new technologies. Microbial fuel cells constitute a technology that uses organic sources for electricity generation. This research gives a novel means of using Golden Berry waste as fuel for electricity generation through microbial fuel cells made at low cost, achieving current and voltage peaks of 4.945 ± 0.150 mA and 1.03 ± 0.02 V, respectively. Conductivity values increased up to 148 ± 1 mS/cm and pH increased up to 8.04 ± 0.12 on the last day. The internal resistance of cells was 194.04 ± 0.0471 Ω, while power density was 62.5 ± 2 mW/cm2 at a current density of 0.049 A/cm2. Transmittance peaks of the Fourier-transform infrared (FTIR) spectrum showed a decrease when comparing the initial and final spectra, while the bacterium Stenotrophomonas maltophilia was molecularly identified with an identity percentage of 99.93%. The three cells connected in series managed to generate 2.90 V, enough to turn on a TV remote control. This research has great potential to be scalable if it is possible to increase the electrical parameters, generating great benefits for companies, farmers, and the population involved in the production and marketing of this fruit.

Shir Reen Chia, Jing Ling, Wen Yi Chia et al.

Green Chemistry • 2023

Future sustainable approach of bioenergy production that uses microalgae–bacteria consortium to produce bioelectricity and biofuel for industrial and daily activities.

Jakub Dziegielowski, Benjamin Metcalfe, Paola Villegas-Guzmán et al.

Applied Energy • 2020

Shuli Zhu, Ke Zhang, Wei Chen et al.

Journal of Environmental Engineering • 2023

In view of the current bottlenecks of low nitrogen and phosphorus removal efficiency and high cathode cost of microbial fuel cells (MFCs), this study constructed single-chamber biocathode MFCs to carry out related research. Single-chamber MFCs with microalgae were fabricated, and nitrogen removal efficiency and greenhouse gas emissions (GHG) were investigated. The results indicated that algae MFCs could significantly reduce GHG (CH4, CO2, and N2O) emissions through the competition of electron donor and sequestrating atmospheric CO2. Compared with the control group, the microalgal MFC significantly promoted the removal of total nitrogen (TN) and total phosphorus (TP). The highest open-circuit voltage (0.33 V) and power density (49 mW m−3) were observed in the closed circuit with algae (CC) reactor. Running MFC significantly increased the biomass of algae and produced good quality of biofuel. Quantitative polymerase chain reaction (q-PCR) analysis indicated that mcrA gene copies in the CC reactor (3.2×103 copies mL−1) were significantly higher than those of the no algae (NA) and CC reactors, while the lowest denitrifying gene copies (narG, nirS, and nosZ) were observed in the NA reactor. The Chloroflexi (22%) and Proteobacteria (31%) were the predominant bacterial communities in the CC reactor. Geobacter and Desulfobulbus were the main genera of exoelectrogens. This study can provide reference for nutrients (nitrogen, phosphorus) removal and GHG control in MFC wastewater treatment, but its long-term stability needs to be further studied.

E. Elakkiya, Subramaniapillai Niju

Energy Sources Part A Recovery Utilization and Environmental Effects • 2020

Microbial fuel cells have been constantly explored as robust technology for complex industrial wastewater treatment. The partial treatment of wastewater in anode chamber of MFC discourages its ability to thrive as stand-alone treatment process and further necessitates secondary treatment, prior to disposal. In our study, we have evaluated sequential treatment of ghee industry wastewater in the anode (primary) and later in microalgae-based biocathode chamber (secondary) to improve the treatment efficiency of bioelectrochemical system. The wastewater collected from ghee manufacturing unit was biochemically treated in the anode chamber after primary sedimentation and at the end of each batch, the anode effluent was transferred to a transient beaker and was used as a source for microalgal growth in cathode chamber without any modification. On comparison with conventional anaerobic treatment, microbial fuel cell could render higher COD removal with lower batch time. The highest power density and current density of 13.7 mW m−2 and 53.5 mA m−2 was produced with abiotic cathode. Though the power production was low in photo-bioelectrochemical system (3.33 mW m−2, 13.45 mA m−2) compared to abiotic cathode the treatment efficiency improved to 96%. Further, the photo-bioelectrochemical reactors enabled eco-friendly and efficient wastewater treatment with considerable power production.

Abdulrahman Itopa Suleiman, Ahmad Abdulrazaq Itopa, Mustapha Omenesa Idris et al.

Eurasian journal of physics and functional materials • 2025

Microbial fuel cell technology is seen as a viable replacement for conventional fossil fuels. It holds significant promises for energy generation, waste management and biomass enhancement. They are viewed as an emerging and economical solution for treating organic waste while generating bioelectricity. To ensure their practical application, careful optimization and precise design are essential. However, there are certain technological hurdles, including low power efficiency and operating stability. These challenges hinder the feasibility and commercialization of MFC systems. The technology behind microbial fuel cells has been shown to effectively treat chemical waste while recovering valuable chemical products like heavy metals, all while generating electrical energy. However, a major obstacle in the development of MFCs is scaling them up for real-world applications, which involves enhancing the potential for the treatment of wastewater and generating energy from several cells within a single MFC system. This review provides an extensive overview of recent breakthroughs in MFC technology, the examination of many substrates, microbial processes in MFCs, fruitful applications of this technology and insights for researchers investigating various factors in microbial fuel cell studies.

Rebecca Bährle, Stefanie Böhnke, Jonas Englhard et al.

Bioresources and Bioprocessing • 2023

Anthropogenic carbon dioxide (CO 2 ) levels are rising to alarming concentrations in earth's atmosphere, causing adverse effects and global climate changes. In the last century, innovative research on CO 2 reduction using chemical, photochemical, electrochemical and enzymatic approaches has been addressed. In particular, natural CO 2 conversion serves as a model for many processes and extensive studies on microbes and enzymes regarding redox reactions involving CO 2 have already been conducted. In this review we focus on the enzymatic conversion of CO 2 to carbon monoxide (CO) as the chemical conversion downstream of CO production render CO particularly attractive as a key intermediate. We briefly discuss the different currently known natural autotrophic CO 2 fixation pathways, focusing on the reversible reaction of CO 2 , two electrons and protons to CO and water, catalyzed by carbon monoxide dehydrogenases (CODHs). We then move on to classify the different type of CODHs, involved catalyzed chemical reactions and coupled metabolisms. Finally, we discuss applications of CODH enzymes in photochemical and electrochemical cells to harness CO 2 from the environment transforming it into commodity chemicals.