Search Results (129)

Microbial fuel cells (MFCs) are an emerging technology that converts the chemical energy stored in organic substrates into electrical energy using microorganisms as catalysts. However, their performance is often limited by the anode design and architecture. To address this, conductive anodes with well-defined pore sizes were manufactured via 3D printing and evaluated for electrical energy generation and wastewater treatment in microbial fuel cells. The maximum power density, coulombic efficiency, and accumulated biomass observed were 14.94 mW/m², 4.87 ± 0.56%, and 0.186 ± 0.025 g, respectively, for the anode with a 2.3 mm pore size. The maximum chemical oxygen demand (COD) removal efficiency was 86.98 ± 1.89% for the anode with a pore size of 1.6 mm. However, this difference was minimal and not significant compared to the anode with a 2.3 mm pore size, which achieved 85.77 ± 2.31%. Additionally, the lowest internal resistance observed was 1246.44 Ω, corresponding to the MFC equipped with the anode with a pore size of 2.3 mm. Taken together, these results indicate that, when using 3D-printed anodes with controlled architectures, an intermediate pore size, neither too large nor too small, provides an adequate balance between electrochemical performance and efficient wastewater treatment in microbial fuel cells. Full article

Microbial imbalance and the spread of pathogenic microorganisms pose severe threats to human health and ecological security. Traditional microbial detection methods suffer from several drawbacks such as long detection time, low sensitivity, and insufficient specificity. As an emerging fluorescent probe, carbon dots (CDs) offer an innovative direction for microbial labeling and detection due to their ultra-small particle size, unique optical properties, excellent biocompatibility, and facile surface modifiability. Herein, this article reviews the research progress of CDs on microbial labeling and detection. The content covers a brief introduction of CDs and explores the main recognition strategies including non-covalent interactions and biomolecule-mediated targeted binding. It also elaborates on the application status of multi-modal sensing technologies for microbial detection, such as CDs-based fluorescent sensing, electrochemical sensing, and surface-enhanced Raman scattering (SERS) sensing. Additionally, the challenges faced in current research, such as achieving simultaneous detection of multiple pathogens and in vivo dynamic tracking, are analyzed, and the development prospects of CDs in fields like clinical diagnosis and public health monitoring are prospected. This review aims to provide comprehensive references for further research and application of CDs in the field of microbial detection. Full article

The intensifying global challenges of water scarcity and widespread microbial contamination underscore the urgent need for the development of efficient, chemical-free disinfection technologies. Here, we developed a compact boron-doped diamond (BDD)-based electrochemical water treatment system that generates reactive oxygen species (ROS) in situ and evaluated its antimicrobial performance using ROS-on/off controls. Bactericidal efficacy was assessed against representative Gram-negative Escherichia coli (E. coli), Gram-positive Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), a clinically relevant Gram-negative pathogen with biofilm-forming and stress-resistant properties. Under ROS-on operation, viable counts were reduced from ~10⁶ CFU/mL to near the detection limit, corresponding to 5–6 log10 reductions across all tested species, whereas ROS-off treatment showed negligible effects. The system retained strong disinfection activity in complex real water matrices, including hand-washing water, laboratory wastewater, and pond wastewater. ROS-treated water also disrupted pre-formed mono-species biofilms in a time-dependent manner, as assessed by crystal violet staining and semi-quantitative biomass analysis. A preliminary mouse exposure assessment did not reveal obvious histopathological abnormalities or hematological changes under the tested conditions. These results demonstrate that BDD-enabled electrochemical ROS water provides a rapid, reagent-free approach for bacterial inactivation and biofilm control, with potential applicability across diverse water-related settings, while acknowledging that further studies on complex natural microbial communities are warranted. Full article

Eutrophication is a major threat to freshwater ecosystems, leading to harmful algal blooms, biodiversity loss, and hypoxia. Excessive nutrient loading, primarily from nitrates and phosphates, is driven by fertilizer runoff, sewage discharge, and agricultural practices. Sediment microbial fuel cells (sMFCs) have emerged as a potential bioremediation strategy for nutrient removal while generating electricity. Although various studies have explored ways to enhance sMFC performance, limited research has examined the relationship between external resistance, electricity generation, and nutrient removal efficiency. This study demonstrated effective nutrient removal from overlying water, with 1200 Ω achieving the highest nitrate and phosphate removal efficiency at 59.0% and 32.2%, respectively. The impact of external resistances (510 Ω and 1200 Ω) on sMFC performance was evaluated, with the 1200 Ω configuration generating a maximum voltage of 466.7 mV and the 510 Ω configuration generating a maximum current of 0.56 mA. These findings show that external resistance plays a major role in both electrochemical performance and nutrient-removal efficiency. Higher external resistance consistently resulted in greater voltage output and improved removal of nitrate and phosphate. The findings also indicate that sMFCs can serve as a dual-purpose technology for nutrient removal and electricity generation. The power output may be sufficient to support small, eco-friendly biosensing devices in remote aquatic environments while mitigating eutrophication. Full article

Microbial fuel cell (MFC) technology represents a promising bioelectrochemical approach for the simultaneous generation of electricity and treatment of high-strength wastewater. However, the performance of MFCs strongly depends on the metabolic potential and synergistic interactions of the inoculated microbial community. This study evaluated the electrochemical activity and COD removal efficiency of three individual bacterial strains, Lysinibacillus sphericus A1, Bacillus cereus A2 and Lactococcus lactis A4, compared with a developed consortium under long-term operation using poultry slaughterhouse wastewater as a substrate. All inocula were tested in dual-chamber MFCs for 30 days, and performance indicators included power output, voltage, and removal of chemical oxygen demand (COD). The consortium showed the highest power of 170 mW/m² and the optimal voltage–current ratio at a current of 900 mA/m² and 245 mV under decreasing external resistance from 1000 to 50 Ω. The highest COD removal (84.4%) was also recorded, surpassing all pure cultures and demonstrating a significant improvement compared with B. cereus A2 and L. lactis A4. Meanwhile, the lowest power of 52 mA/m² was recorded during testing of L. lactis A4, at 650 mA/m² and 120 mV. Compared with single cultures, the consortium produced approximately 15% higher power density than L. sphericus A1, about 29% higher than B. cereus A2, and more than threefold higher than L. lactis A4. This study highlights the potential of a consortium as an efficient biocatalyst for MFC-mediated wastewater treatment and suggests that selecting complementary strains with diverse metabolic functions can substantially improve system performance. Full article

Microplastics (MPs) have emerged as persistent environmental pollutants with adverse effects on ecosystems and human health. Conventional removal methods, such as filtration and sedimentation, primarily rely on physical separation without addressing the degradation of MPs, leading to their accumulation and the risk of secondary pollution. This review explores the potential of advanced oxidation processes (AOPs), including photocatalysis, electrochemical oxidation, Fenton processes, sulfate radical-based oxidation, sonochemical treatment, ozonation, and plasma technologies, which generate reactive oxygen and nitrogen species capable of promoting polymer chain scission, microbial biodegradation, and the oxidative fragmentation and mineralization of MPs into non-toxic byproducts. Hybrid AOP systems combined with biological treatments or membrane-based filtration are also examined for their effectiveness in degrading MPs, as well as for scalability and the environmental impacts of their byproducts when integrated into existing wastewater treatment systems. The review further discusses challenges related to operational parameters, energy consumption, and the formation of secondary pollutants. By identifying current knowledge gaps and future research directions, this review provides insights into optimizing AOPs and integrations of AOPs with biological treatments or membrane-based processes for sustainable MP remediation and water treatment applications. Full article

Hydrogen production technologies are undergoing rapid diversification, driven by the dual imperative of decarbonization and resource circularity. While conventional water electrolysis, particularly PEM and alkaline systems, represents a mature and scalable solution for centralized hydrogen generation, biologically mediated pathways such as microbial electrolysis cells (MECs), dark fermentation, and anaerobic digestion are gaining visibility as decentralized, low-energy alternatives. This review presents a bibliometric analysis of hydrogen research from 2021 to 2026, based on three multi-query strategies that retrieved 6017 works in MQ1, 7551 works in MQ2, and 1930 works in MQ3. The year 2026 is included in the dataset because Scopus indexes articles already accepted and released in early access, assigning them their forthcoming official publication year. Keyword co-occurrence mapping using VOSviewer highlights thematic clusters and disciplinary shifts. The results reveal a strong dominance of electrochemical research, with biohydrogen production emerging as a distinct but less mature frontier rooted in biotechnology and environmental science. MECs, in particular, occupy a transitional zone between electrochemical and biological paradigms, offering multifunctional platforms for simultaneous waste valorization and hydrogen generation. However, their low Technology Readiness Levels (TRLs) and unresolved engineering challenges limit their current scalability. The comparative analysis of bibliometric queries underscores the importance of integrating electrochemical and biotechnological approaches to build a resilient and context-adaptive hydrogen economy. This study provides a structured overview of the evolving knowledge landscape and identifies key directions for future interdisciplinary research and innovation. Full article

The expensive nature and limited availability of platinum (Pt) cathodes pose a significant challenge for the widespread adoption of microbial fuel cell (MFC) technology. Although many alternatives have been studied, very few reports provide a systematic head-to-head comparison of different Ni–oxide cathodes under the same operational conditions. This research investigates cost-effective nickel-based metal oxide composites (Ni–TiO₂, Ni–Cr₂O₃, Ni–Al₂O₃) as catalysts for the oxygen reduction reaction (ORR), using Pt as a reference point. The performance of the MFC was thoroughly evaluated in terms of power output, chemical oxygen demand (COD) removal, and Coulombic efficiency (CE). The Pt cathode exhibited the highest performance (275 mW m⁻², 87% COD removal, 35% CE), confirming its catalytic advantages. Among the alternative materials, the Ni–TiO₂ composite yielded the best outcomes (224 mW m⁻², 79% COD removal, 17.7% CE), markedly surpassing the performances of Ni–Cr₂O₃ (162 mW m⁻², 72%, 24% CE) and Ni–Al₂O₃ (134 mW m⁻², 64%, 11.6% CE). Koutecký–Levich analysis clarified the mechanisms at play: Pt facilitated a direct 4-electron ORR process, while the composites operated through a 2-electron mechanism. Notably, the semiconductor properties of Ni–TiO₂ resulted in a higher electron transfer number (n = 2.8) compared to the other composites (n ≈ 2.3), which accounts for its increased efficiency. With its low production cost, Ni–TiO₂ presents an exceptional cost-to-performance ratio. By linking catalytic performance directly to the electronic nature of the oxide supports, this study offers clear design guidelines for selecting non-precious cathodes. The dual evaluation of electrochemical efficiency and cost-to-performance distinguishes this study from prior reports and underscores its practical significance and originality. This study highlights Ni–TiO₂ as a highly sustainable and economically viable catalyst, making it a strong candidate to replace Pt for practical MFC applications that focus on simultaneous power generation and wastewater treatment. Full article

Microbial fuel cells are a new alternative for sustainable energy generation and wastewater treatment technology. To scale up this technology, cost-effective electrodes are required. The electrochemical reduction of oxygen at the cathode is a key reaction for power generation. Noble metals, especially Pt, are extensively used as cathode catalysts in MFC; however, its application is limited to its high cost and catalyst poisoning. Ferroelectric materials are reported as a good candidate due to their spontaneous polarization. The main objective of this study is to prepare and characterize the cost-effective ferroelectric materials LiTa_0.6 Nb_0.4 O₃ and Li_0.95 Ta_0.57 Nb_0.38 Mg_0.15 O₃ in order to test their catalytic activity in air-cathode MFC. Powders were prepared following the solid-state synthesis and characterized using Scanning Electron Microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. To evaluate the electrochemical performance of the catalysts, electrochemical studies such as EIS, CV, LSV, and CA were conducted. In MFC, the performance of our material has been investigated using COD determination and polarization measurement. The obtained results demonstrate the potential of Li_0.95 Ta_0.57 Nb_0.38 Mg_0.15 O₃ as a low-cost and effective catalyst material in MFCs, showing a high COD removal up to 75%, and power-density output of 764 mW/m². Full article

Anaerobic digestion (AD) is increasingly recognized as a key technology for renewable energy generation and sustainable waste management within the circular economy. However, its performance is highly sensitive to feedstock variability and environmental fluctuations, making stable operation and high methane yields difficult to sustain. Conventional monitoring and control systems, based on limited sensors and mechanistic models, often fail to anticipate disturbances or optimize process performance. This review discusses recent progress in electrochemical, optical, spectroscopic, microbial, and hybrid sensors, highlighting their advantages and limitations in artificial intelligence (AI)-assisted monitoring. The role of soft sensors, data preprocessing, feature engineering, and explainable AI is emphasized to enable predictive and adaptive process control. Various machine learning (ML) techniques, including neural networks, support vector machines, ensemble methods, and hybrid gray-box models, are evaluated for yield forecasting, anomaly detection, and operational optimization. Persistent challenges include sensor fouling, calibration drift, and the lack of standardized open datasets. Emerging strategies such as digital twins, data augmentation, and automated optimization frameworks are proposed to address these issues. Future progress will rely on more robust sensors, shared datasets, and interpretable AI tools to achieve predictive, transparent, and efficient biogas production supporting the energy transition. Full article

Reinforced concrete durability depends on a passive oxide film protecting embedded steel, sustained by high-alkalinity pore solutions. Cracking fundamentally alters transport, allowing rapid chloride and carbon dioxide ingress, which undermines passivity and accelerates corrosion. Self-healing concrete technologies aim to autonomously restore transport barriers and reestablish electrochemical stability. This review critically synthesizes evidence on healing effectiveness for corrosion mitigation through a dual framework of barrier restoration and interface stabilization, integrating depth-resolved chloride profiles with electrochemical performance indices. Critically, visual crack closure proves an unreliable indicator of corrosion protection. Healing mechanisms exhibit characteristic spatial signatures: autogenous and microbial approaches preferentially seal surface zones with diminishing effectiveness at reinforcement depth, while encapsulated low-viscosity polymers achieve greater depth continuity. However, electrochemical recovery consistently lags transport recovery, with healed specimens achieving only partial restoration of intact corrosion resistance. Recovery effectiveness depends on crack geometry, moisture conditions, and healing mechanism characteristics, with systems performing effectively only within narrow, condition-specific windows. Effective corrosion protection requires coordinated barrier and interface strategies targeting both bulk transport and steel surface chemistry. The path forward demands rigorous field validation emphasizing electrochemical outcomes over appearance metrics, long-term durability assessment, and performance-based verification frameworks to enable predictable service life extension. Full article

Microbial electrosynthesis (MES) has emerged as a promising bio-electrochemical technology for sustainable CO₂ conversion into valuable organic compounds since it uses living electroactive microbes to directly convert CO₂ into value-added products. This review synthesizes advancements in MES from 2010 to 2025, focusing on the electrode materials, microbial communities, reactor engineering, performance trends, techno-economic evaluations, and future challenges, especially on the results reported between 2020 and 2025, thus highlighting that MES technology is now a technology to be reckoned with in the spectrum of biofuel technology production. While the current productivity and scalability of microbial electrochemical systems (MESs) remain limited compared to conventional CO₂ conversion technologies, MES offers distinct advantages, including process simplicity, as it operates under ambient conditions without the need for high pressures or temperatures; modularity, allowing reactors to be stacked or scaled incrementally to match varying throughput requirements; and seamless integration with circular economy strategies, enabling the direct valorization of waste streams, wastewater, or renewable electricity into valuable multi-carbon products. These features position MES as a promising platform for sustainable and adaptable CO₂ utilization, particularly in decentralized or resource-constrained settings. Recent innovations in electrode materials, such as conductive polymers and metal–organic frameworks, have enhanced electron transfer efficiency and microbial attachment, leading to improved MES performance. The development of diverse microbial consortia has expanded the range of products achievable through MES, with studies highlighting the importance of microbial interactions and metabolic pathways in product formation. Advancements in reactor design, including continuous-flow systems and membrane-less configurations, have addressed scalability issues, enhancing mass transfer and system stability. Performance metrics, such as the current densities and product yields, have improved due to exceptionally high product selectivity and surface-area-normalized production compared to abiotic systems, demonstrating the potential of MES for industrial applications. Techno-economic analyses indicate that while MES offers promising economic prospects, challenges related to cost-effective electrode materials and system integration remain. Future research should focus on optimizing microbial communities, developing advanced electrode materials, and designing scalable reactors to overcome the existing limitations. Addressing these challenges will be crucial for the commercialization of MES as a viable technology for sustainable chemical production. Microbial electrosynthesis (MES) offers a novel route to biofuels by directly converting CO₂ and renewable electricity into energy carriers, bypassing the costly biomass feedstocks required in conventional pathways. With advances in electrode materials, reactor engineering, and microbial performance, MES could achieve cost-competitive, carbon-neutral fuels, positioning it as a critical complement to future biofuel technologies. Full article

The rapid rise of antibiotic-resistant bacteria (ABR) presents an urgent global health challenge, necessitating the development of efficient and scalable diagnostic technologies. Electrochemical biosensors have emerged as a promising solution, offering high sensitivity, specificity, and adaptability for point-of-care applications. These innovative platforms utilize bio-recognition elements, advanced electrode materials, microbial enzymes, and redox-active metabolites to identify antibiotic resistance profiles at a molecular level. Recent progress in microfluidics and lab-on-a-chip systems has enabled real-time, high-throughput antimicrobial susceptibility testing, significantly improving diagnostic precision and speed. This review aims to critically evaluate recent advances in electrochemical biosensing strategies for detecting ABR, identify key challenges, and propose future directions to enhance clinical applicability. Key developments include bio-receptor-based detection strategies, novel electrode surfaces, and multiplexed platforms integrated with microfluidic systems. Additionally, this review examines essential biomarkers for detecting antibiotic resistance and explores key challenges, including variability in biomarker expression and sensor reproducibility. It also highlights practical barriers to clinical implementation, such as cost constraints and scalability concerns. By presenting innovative approaches, such as cost-effective material alternatives, advanced analytical techniques, and portable biosensing systems, this review outlines a strategic pathway for enhancing the accessibility and effectiveness of electrochemical biosensors in antibiotic resistance management. Full article

This study investigated the effects of applied voltage on methane fermentation using separate reactors for the anode and cathode, with activated carbon felt as electrodes and a constant voltage of 0.7 V. Compared to the control, the cathode reactor exhibited approximately 1.2 times higher methane production and 1.3 times higher methane concentration, whereas the anode reactor showed a reduction to about 0.5 times and 0.8 times, respectively. Microbial analysis revealed that the anode reactor created an electron-accepting environment, promoting the growth of Clostridium sensu stricto 1 and Fastidiosipila, both contributing to organic acid (electron) production. Conversely, the cathode reactor established an electron-donating environment, enhancing methane production by hydrogenotrophic methanogens such as Methanoculleus and Methanobacterium. Although similar methanogen levels were found in the anode reactor, methane production was higher in the cathode reactor. These findings indicate that the anode facilitates organic acid production via electron acceptance, while the cathode acts as an electron donor that promotes hydrogenotrophic methanogenesis. This study provides a clear evaluation of the effects of microbial electrochemical technologies on methane fermentation, demonstrating their potential to stimulate microbial activities and enhance methane production. Full article

The rapid and accurate detection of pathogenic bacteria and viruses is critical for infectious disease control and public health protection. While conventional methods (e.g., culture, microscopy, serology, and PCR) are widely used, they are often limited by lengthy processing times, high costs, and specialized equipment requirements. In recent years, metal nanocluster (MNC)-based biosensors have emerged as powerful diagnostic platforms due to their unique optical, catalytic, and electrochemical properties. This systematic review comprehensively surveys advancements in MNC-based biosensors for bacterial and viral pathogen detection, focusing on optical (colorimetric and fluorescence) and electrochemical platforms. Three key aspects are emphasized: (1) detection mechanisms, (2) nanocluster types and properties, and (3) applications in clinical diagnostics, environmental monitoring, and food safety. The literature demonstrates that MNC-based biosensors provide high sensitivity, specificity, portability, and cost-efficiency. Moreover, the integration of nanotechnology with biosensing platforms enables real-time and point-of-care diagnostics. This review also discusses the limitations and future directions of the technology, emphasizing the need for enhanced stability, multiplex detection capability, and clinical validation. The findings offer valuable insights for developing next-generation biosensors with improved functionality and broader applicability in microbial diagnostics. Full article