Power Output Of Microbial Fuel Cells Research Articles

The influence of benzene on the composition, diversity and performance of the anodic bacterial community in glucose-fed microbial fuel cells.

Bioelectrochemical systems offer unique opportunities to remove recalcitrant environmental pollutants in a net positive energy process, although it remains challenging because of the toxic character of such compounds. In this study, microbial fuel cell (MFC) technology was applied to investigate the benzene degradation process for more than 160 days, where glucose was used as a co-metabolite and a control. We have applied an inoculation strategy that led to the development of 10 individual microbial communities. The electrochemical dynamics of MFC efficiency was observed, along with their 1H NMR metabolic fingerprints and analysis of the microbial community. The highest power density of 120 mW/m2 was recorded in the final period of the experiment when benzene/glucose was used as fuel. This is the highest value reported in a benzene/co-substrate system. Metabolite analysis confirmed the full removal of benzene, while the dominance of fermentation products indicated the strong occurrence of non-electrogenic reactions. Based on 16S rRNA gene amplicon sequencing, bacterial community analysis revealed several petroleum-degrading microorganisms, electroactive species and biosurfactant producers. The dominant species were recognised as Citrobacter freundii and Arcobacter faecis. Strong, positive impact of the presence of benzene on the alpha diversity was recorded, underlining the high complexity of the bioelectrochemically supported degradation of petroleum compounds. This study reveals the importance of supporting the bioelectrochemical degradation process with auxiliary substrates and inoculation strategies that allow the communities to reach sufficient diversity to improve the power output and degradation efficiency in MFCs beyond the previously known limits. This study, for the first time, provides an outlook on the syntrophic activity of biosurfactant producers and petroleum degraders towards the efficient removal and conversion of recalcitrant hydrophobic compounds into electricity in MFCs.

Asymmetric reactors as an innovative approach for optimum microbial fuel cells performance

Microbial fuel cells (MFCs) exhibit asymmetric overpotentials and redox potentials/rates at the cathode and anode. However, the impact of this asymmetric on power density and anode microbial community remains poorly understood. In this study, asymmetric reactors were designed for H-type MFCs to investigate this configuration. Contrary to the initial expectation of increased MFC power output with larger cathode volumes, it was unexpectedly found that the small-cathode reactor outperformed the large-cathode reactor, achieving a 61 % increase in maximum power density. Electrochemical characterization revealed a slightly lower charge transfer resistance (29.34 Ω) in the small-cathode reactor with carbon-felt anode biofilm in PBS. Moreover, 16S rRNA sequence analysis showed that the small-cathode reactor harbored a higher proportion of anaerobic bacteria (83 %), lower species diversity, and a higher abundance of exoelectrogens. Additionally, higher abundances of key gene modules (top eight), such as quinone oxidoreductase and citrate cycle, were observed in the small-cathode reactor. The anode biofilms in both reactors also synthesized some vitamins, such as menaquinone and thiamine. Furthermore, compared to the large-cathode reactor, each set of the small-cathode reactor saved ¥ 20, 23 g of borosilicate, and 55 mL of cathode electrolytes. This study sheds light on the interplay between reactor conformation and performance, contributing to the development of low-cost, high-performance MFCs for real field conditions.

Catalyzing oxygen reduction by morphologically engineered ZIF-derived carbon composite catalysts in dual-chamber microbial fuel cells

From the past decades, microbial fuel cells (MFCs) have evolved as a green alternative to produce electrical energy from organic matter degradation. Cathode modification significantly enhances the overall MFC performance. In this work, we report on ZIF-8 and carbon nanotubes (CNTs) derived catalyst materials as cathode for MFC. The catalysts were prepared via high-temperature pyrolysis at 900 °C and were physically characterized by various analytical techniques. All the catalyst materials carry tubular arrangements of CNTs covering the ZIF-8 crystals and exhibit highly micro-mesoporous texture. The electrocatalytic activity for oxygen reduction reaction (ORR) was studied in 0.1 M phosphate buffer at a catalyst loading of 0.2 mg cm−2. The FeCo-N-C@900 catalyst showed the highest ORR activity with half-wave potential of 0.71 V vs RHE and limiting current density of −5.62 mA cm−2 at 1900 rpm. When tested in MFC, FeCo-N-C@900 coated cathode delivered the maximum power density of 1557 mW m−2 (comparable to Pt/C catalyst reaching Pmax of 1681 mW m−2) with chemical oxygen demand (COD) removal efficiency of 87.3%. The Next generation DNA sequencing analysis revealed the accumulation of various exoelectrogenic bacterial strains i.e., Bacillus, Desulfovibrio, Comamonadaceae sp. etc. commonly found in anaerobic biomass and showing the successful enrichment of the biofilm responsible for oxidizing organic matter at the anode. The present study illustrates the potential of transitional metal-doped ZIF-8 and CNTs composite electrocatalysts for enhancing the power output of MFC with generating promising power and current densities.

Exogenous electric field as a biochemical driving factor for extracellular electron transfer: Increasing power output of microbial fuel cell

Although microbial fuel cells (MFCs) offer a promising avenue for clean power production, they are hindered by inefficient extracellular electron transfer (EET), thereby resulting in a low power output. This study focused on augmenting MFC power by boosting the EET rate using an exogenous electric field (EEF). By leveraging the dual benefits of microbial electrolysis cells (MECs) in organic waste treatment and energy recovery, we developed an MFC–MEC system that utilizes the EEF from MEC as a connecting link. Two configurations, EEF in the same direction (SD-MFC–MEC) and EEF in the reverse direction (RD-MFC–MEC), were used to examine the EET kinetic rate at the MFC anode in the EEF environment using various electrochemical methods for quantitative evaluation. Our findings revealed that EEF significantly enhanced MFC anode biofilm formation and electrochemical activity, leading to a prominent improvement in electrode reaction rates. The EET rate constants in the SD-MFC–MEC and RD-MFC–MEC were more than double those in the control R-MFC, with power density increases of 117.8% and 108.4%, respectively. The formation of electrochemically active sites within the biofilm induced by EEF has emerged as a crucial factor in amplifying the EET rate, and consequently, the MFC power output. Additionally, the variation in EET rate constants between the SD-MFC–MEC and RD-MFC–MEC was minimal, thereby indicating the negligible impact of the EEF orientation on the EET efficiency. This study provides a novel method for quantitatively examining EET rates, opens up new avenues for further facilitating microbe-to-electrode electron transfer, and promotes the application of MFC–MEC systems in energy recovery, CO2 emission reduction, and waste treatment.

Stimulation of electron transfer in electricigens by MnxCoySz heterostructure for the enhanced power generation of microbial fuel cell

Microbial fuel cells (MFCs) are an efficient approach to converting energy existing in waste into electricity. However, MFCs still face problems such as low electron transfer rate and low power density. Herein, the anode properties dominate the performance of MFC. This study manufactured a high-performance MnCo2S4–CoS1.097/carbon black carbon felt (T-MCS-CS/CB-CF) anode through a two-step hydrothermal method. T-MCS-CS/CB catalyst exhibited superior surface roughness and mesoporous structure. Besides, the excellent electrocatalytic activity of the T-MCS-CS/CB catalyst with the heterostructure resulted in the higher power output. After biofilm formation, T-MCS-CS/CB-CF anode exhibited lower Rct (9.29 Ω) than MnCo2S4-Co4S3/ carbon black carbon felt (MCS-CS/CB-CF (15.83 Ω)), carbon black carbon felt (CB-CF (29.52 Ω)) and CF anode (116.1 Ω), exhibiting higher electrochemical activity. T-MCS-CS/CB-CF anode enhanced extracellular electron transfer (EET) and improved the power density, which was 12.29 times higher (1299.27 mW/m2) than the bare CF (105.70 mW/m2). The relative abundance of Geobacter for T-MCS-CS/CB-CF (21.65 %) was 7.24 times higher than the control CF anode (2.99 %). Moreover, T-MCS-CS/CB modification enriched exoelectrogens/sulfate-reducing bacteria, Desulfovibrio, 4.69 % higher than the CF anode, which attributed to the introduction of CoS1.097. The excellent electrocatalytic activity, surface properties and biocompatibility of T-MCS-CS/CB-CF promoted the power output in MFC. This study provided an effective way of anodic electrocatalyst fabrication for enhancing the power generation of MFC.

Customized Multichannel Measurement System for Microbial Fuel Cell Characterization.

This work presents the development of an automatic and customized measuring system employing sigma-delta analog-to-digital converters and transimpedance amplifiers for precise measurements of voltage and current signals generated by microbial fuel cells (MFCs). The system can perform multi-step discharge protocols to accurately measure the power output of MFCs, and has been calibrated to ensure high precision and low noise measurements. One of the key features of the proposed measuring system is its ability to conduct long-term measurements with variable time steps. Moreover, it is portable and cost-effective, making it ideal for use in laboratories without sophisticated bench instrumentation. The system is expandable, ranging from 2 to 12 channels by adding dual-channel boards, which allows for testing of multiple MFCs simultaneously. The functionality of the system was tested using a six-channel setup, and the results demonstrated its ability to detect and distinguish current signals from different MFCs with varying output characteristics. The power measurements obtained using the system also allow for the determination of the output resistance of the MFCs being tested. Overall, the developed measuring system is a useful tool for characterizing the performance of MFCs, and can be helpful in the optimization and development of sustainable energy production technologies.

Improving microbial fuel cells power output using internal and external optimized, tailored and totally green supercapacitor

Improving microbial fuel cells power output using internal and external optimized, tailored and totally green supercapacitor

Evaluation of the algal-derived biochar as an anode modifier in microbial fuel cells

It's essential to develop low-cost and efficient materials for the anode to stimulate extracellular electron transport and increase power density in microbial electrochemical systems (MES), which can increase energy output. Harmful algal bloom (HAB) can be mitigated by harvesting algal biomass mechanically. Hence, in this study, algal biomass was pyrolyzed to produce inexpensive algal biochar then employed on the anode modifier for productive electron transport. SEM, Raman, BET and XRD analysis was performed to characterize and determine their size, shape, and surface morphology. In the MES, the electrochemical attributes of algal biochar as an electrode material were evaluated using Pseudomonas aeruginosa as a biocatalyst. Using microbial fuel cells (MFCs), the highest possible volumetric power density of 6.8 W/m3 and CE of 9.33 % was obtained with an optimized concentration of 1.5 mg/cm2 biochar-impregnated anodes. These findings display that collected HAB might be used as a cheap anode material to achieve enhanced power output in MFCs with concomitant wastewater treatment.

Microbial Electrochemical Treatment of Methyl Red Dye Degradation Using Co-Culture Method

Methyl red, a synthetic azo dye, was reported for not only being mutagenic but also its persistence has severe consequences on human health, such as cancer, alongside detrimental environmental effects. In the present study, the Pseudomonas putida OsEnB_HZB_G20 strain was isolated from the soil sample to study the catalytic activity for the degradation of methyl red dye. Another isolated strain, the Pseudomonas aeruginosa PA 1_NCHU strain was used as an electroactive anodophile and mixed with the Pseudomonas putida OsEnB_HZB_G20 strain to see the effect of co-culturing on the power generation in single-chambered microbial fuel cells (MFCs). The Pseudomonas putida OsEnB_HZB_G20 and Pseudomonas aeruginosa PA 1_NCHU strains were used as co-culture inoculum in a 1:1 ratio in MFCs. This work uses isolated bacterial strains in a co-culture to treat wastewater with varying methyl red dye concentrations and anolyte pH to investigate its effect on power output in MFCs. This co-culture produced up to 7.3 W/m3 of power density with a 250 mgL−1 of dye concentration, along with 95% decolorization, indicating that the symbiotic relationship between these bacteria resulted in improved MFC performance simultaneous to dye degradation. Furthermore, the co-culture of Pseudomonas putida and Pseudomonas aeruginosa in a 1:1 ratio demonstrated improved power generation in MFCs at an optimized pH of 7.

Sustainable microbial fuel cell functionalized with a bio-waste: A feasible route to formaldehyde bioremediation along with bioelectricity generation

Bioelectrochemical systems, especially microbial fuel cell (MFC), are gaining popularity owing to their eco-friendly and energy generation with bioremediation. Due to its unstable electrode material, MFCs have poor electron transportation and production. To increase electron transport and bacterial biocompatibility, better anode materials are needed. Waste palm kernel shell-derived graphene oxide (PKS-GO) and reduced graphene oxide (PKS-rGO) were used to produce the anode electrodes to increase electron transport. The MFC with the PKS-rGO anode generated more energy (24.47 mW/m2) than the PKS-GO anode (13.77 mW/m2). Similarly, the maximum current densities recorded for both anodes were 84.98 mA/m2 for PKS-rGO and 63.74 mA/m2 for PKS-GO. Additionally, the PKS-GO anode showed a 0.00015F/g specific capacitance (Cp) value, whereas the PKS-rGO anode had a Cp value of 0.00021F/g. The enhanced capacitance of the PKS-rGO anode may be due to redox enzymes on microbial cell membranes. The electrochemical impendence spectroscopy also showed a rapid transportation rate of electrons in the case of the PKS-rGO anode. PKS-GO's anode has 1240 ῼ internal resistance, whereas PKS-rGO has 232 ῼ. The secondary use of MFC in wastewater treatment was also taken into account. The PKS-rGO anode (87 %) is more effective in bioremediating formaldehyde (FA) than the PKS-GO anode (81.70 %). The sequence reveals a prominent species of Niallia circulans strain for the PKS-GO anode, and two dominant species for the PKS-rGO anode, Bacillus siamensis strain and Bacillus velezensis strain. A comparative overview shows the effectiveness of the material compared to previous studies. Critical challenges constraining progress in MFC power output enhancement and future perspectives are also included.

Fabrication of a polyvinyl alcohol-bentonite composite coated on a carbon felt anode for improving yeast microbial fuel cell performance

Bentonite-Polyvinyl Alcohol (PVA/Bentonite) is constructed by mixing bentonite with PVA. It is then coated on carbon felt (CF) and proposed as a replacement for conventional carbon-based materials in the anode of yeast Microbial Fuel Cell (MFC) with biofilm development. The selected anodic benchmarks are three-dimensional CF that is unmodified, inexpensive, flexible, spongy, and electrically conductive. Adding a [PVA/Bentonite] composite to a CF anode increased the power output of yeast MFC by 6–100%, while the voltage increased by 37–62%. Comparatively, the CF/[PVA0.2/Bentonite] layer resulted in superior catalytic activities, such as a high electron transfer rate constant of 0.580 s−1, a low Rct value of 1.3 Ω, a low Cs of 20.27 F/g, a low Cdl of 162 F, and a W value of 66.59 μΩ/s0.5. The MPD of the yeast MFC using the layer was 25.70 ± 5.5 mW/m2. The more PVA and bentonite in the CF, more challenging it is for biofilm to develop on the anode surface in yeast MFCs. At certain concentration, however, this [PVA/Bentonite] mixture may tend to prefer protons and electrons generated by yeast. This research reveals that the close interaction of bentonite and CF through PVA might enhance the performance of yeast MFC.

Magnesium Cobaltite Embedded in Corncob-Derived Nitrogen-Doped Carbon as a Cathode Catalyst for Power Generation in Microbial Fuel Cells.

Microbial fuel cells (MFCs) have drawn attention among renewable energy devices. High capital cost, poor durability, and slow oxygen reduction reaction (ORR) kinetics are the major hindrances in the commercialization of the technology. In this work, an environmentally benign approach is followed to synthesize a composite of magnesium cobaltite (MgCo2O4) embedded in nitrogen-doped carbon to optimize the performance of MFCs. Detailed characterization confirms the formation of MgCo2O4 nanostructures in the catalyst treated at 700 °C. Electrochemical studies suggest the superior performance of the MgCo2O4/NC-700 catalyst with a peak reduction current of -0.068 mA and a charge transfer resistance (Rct) of 40.5 Ω. The performance of the air cathodes is evaluated using activated sludge as inoculum in the anode chamber in single-chamber MFCs. The power output of MFC with MgCo2O4/NC-700 as an air cathode reaching 873.81 mW m-2 is 59.56 and 216.05% higher than those of MFCs with Pt/C (547.65 mW m-2) and Co/NC-700 (276.48 mW m-2) cathodes, respectively. These findings suggest that substituting magnesium in transition metal-nitrogen-carbon composites could help realize long-term application as air cathodes for power generation and wastewater treatment in MFCs.

Exploring the effectiveness of microbial fuel cell for the degradation of organic pollutants coupled with bio-energy generation

The ongoing global industrialization has contributed in a significant increase in the release of toxic pollutants into the environment, the majority of which are primarily organic pollutions. When organic pollutants more than permissible limits are in the environment, they pose a serious threat to aquatic life and humans. Various bioremediation and degradation techniques for organic pollutants removal from the environment have been reported; however, their sustainability and efficacy remain insufficient. The overarching goal of this review is to unravel the effectiveness of using the microbial fuel cell (MFC) technique to degrade organic pollutants while improving the energy generation performance of the system. This review explains the various physicochemical and biological factors that influence microbial degradation of organic pollutants. The mechanism of organic pollutants degradation and the interaction of the pollutants with microbes in the MFC system were discussed. Further, this paper highlights a new approach on how organic pollutants increase the MFC power output. A comparative review of the degradation of other toxic pollution and organic pollutants through MFC and their effects on energy generation performance were presented herein. Finally, current challenges, future recommendations, and perspectives were also summarized.

Performance improvement of microbial fuel cells through assembling anodes modified with nanoscale materials

In microbial fuel cell (MFC), the anode is the carrier of microbial attachment and growth, and its material and surface structure play a vital role in MFC electricity generation. Therefore, anode surface optimization is an effective way to improve MFC performance. Although the power generation of bacteria has been confirmed and studied as early as the beginning of the 20th century, up to now, MFC still has the extremely challenging problem of low current and low power output in practical application. To improve the performance of MFC, several strategies have been applied to enhance the bacterial extracellular electron transfer. One promising technology is the genetic engineering approach, and some outstanding research results have been obtained. Another effective strategy is to design and fabricate a high-performance electrode because anode material is the essential factor affecting MFC performance, which provides surface active sites for microbial adhesion, reproduction and interfacial electron transfer. At present, the MFC anodes mainly include carbon-based electrodes and a variety of metal electrodes, but untreated anodes have always been unable to overcome the obstacle of low power output. Anode modification, a common and effective method, is employed for improving the power output of MFC. For this reason, this review is primarily focused on the applications of various anode materials and its nanoscale modification in the field of MFC, including the influence of different anode materials on the power output of MFC, and analyzes the reasons why anode modification enhances output performance. Furthermore, the influence of anode research on the practical application of MFC in the future is prospected.

Structure design of 3D hierarchical porous anode for high performance microbial fuel cells: From macro-to micro-scale

Microbial fuel cell (MFC) is a promising technology that can simultaneously achieve wastewater treatment and energy recovery, but its low power output cannot satisfy the practical application. The performance of bioanodes, determined by the materials and structure, significantly affects the power output of MFCs. Herein, a designing approach is proposed to obtain high-performance bioanodes with the optimized macro- and microstructural using three-dimensional (3D) printing technology and electropolymerization. Through adjusting the distribution of large pores (i.e., 0.7 mm) and small pores (i.e., 0.4 mm) in 3D electrodes, the bioanode possesses an optimized macrostructure with large specific surface areas for the attachment of electroactive bacteria and sufficient mass transfer for bioelectrochemical reaction. Then the surface of electrode is further modified with 3D polypyrrole/graphene oxide (PPy/GO) microstructure to facilitate the formation of biofilm and the electron transfer at the biological/inorganic interfaces. Consequently, the bioanode with optimized macro- and microstructure achieves a high power density of 22.4 ± 0.6 W/m2, which is 18.7 times higher than that of commercial carbon felt electrode. This study brings new insights to design bioanodes in MFCs, providing a promising practical prospect.

A new modification method of metal substrates via candle soot to prepare effective anodes in air‐cathode microbial fuel cells

AbstractBACKGROUNDChoosing applicable anodes can effectively promote the performance of microbial fuel cells (MFCs). This study introduced a novel method to prepare effective metal‐based anodes modified by carbon nanoparticles (CNPs) derived from candle soot. The CNPs can be firmly coated on the metal and the modified metal surfaces show good hydrophilicity.RESULTSThis study used titanium mesh, stainless steel sheet and copper sheet as the anode's substrate, respectively. CNPs could improve the biocompatibility and electrochemical properties of these metals. The power generation performance of MFCs with CNP‐modified anodes has been dramatically enhanced, and the maximum power density is 616 mW m−2 in MFCs with CNP‐modified titanium mesh anode.CONCLUSIONAfter CNP modification, the rough surface and excellent biocompatibility could promote the attachment and growth of microorganisms, which may be the main reasons for the improvement of MFC performance. Besides, this method is suitable to modify different metal substrates. The results showed that the CNP‐coated metal anodes could improve the power output of MFCs compared to pure metal anodes. Therefore, this method has significant advantages in the practical application of MFCs. © 2021 Society of Chemical Industry (SCI).

Investigating Air-Cathode Microbial Fuel Cells Performance under Different Serially and Parallelly Connected Configurations

Microbial fuel cells (MFCs) have recently attracted more attention in the context of sustainable energy production. They can be considered as a future solution for the treatment of organic wastes and the production of bioelectricity. However, the low output voltage and the low produced electricity limit their applications as energy supply systems. The scaling up of MFCs both by developing bigger reactors with multiple electrodes and by connecting several cells in stacked configurations is a valid solution for improving these performances. In this paper, the scaling up of a single air-cathode microbial fuel cell with an internal volume of 28 mL, has been studied to estimate how its performance can be improved (1523 mW/m3, at 0.139 mA). Four stacked configurations and a multi-electrode unit have been designed, developed, and tested. The stacked MFCs consist of 4 reactors (28 mL × 4) that are connected in series, parallel, series/parallel, and parallel/series modes. The multi-electrode unit consists of a bigger reactor (253 mL) with 4 anodes and 4 cathodes. The performance analysis has point ed out that the multi-electrode configuration shows the lowest performances in terms of volumetric power density equal to 471 mW/m3 at 0.345 mA and volumetric energy density of 624.2 Wh/m3. The stacked parallel/series configuration assures both the highest volumetric power density, equal to 2451 mW/m3 (274.6 µW) at 0.524 mA and the highest volumetric energy density, equal to 2742.0 Wh/m3. These results allow affirming that to increase the electric power output of MFCs, the stacked configuration is the optimal strategy from designing point of view.

Graphene-modified biochar anode on the electrical performance of MFC

Improving the power output and other power generation performance is the technical bottleneck restricting the industrial application of microbial fuel cell (MFC). Modification of the anode using nanomaterials can significantly increase the power output of MFC. The negatively charged characteristics of Rhodopseudomonas palustris was utilized to propose electroplating of graphene on the surface of biochar, and preparation of polyaniline (PANI) modified biochar electrode by in situ polymerization. Thus, a graphene oxide/polyaniline modified biochar (GO/PANI@Biochar) anode was prepared. Thus, compared the effects of GO/PANI@Biochar, biochar, traditional carbon cloth (CC), and graphite felt (GF) anodes on the power generation performance of MFC. The results showed that the contact angle θ of the new anode was as low as 0°. The biocompatibility is good, and a large number of electricity-producing microorganisms adhere to the surface of the anode material. The maximum power density of GO/PANI@Biochar anode MFC reached to 2025 mW/m2, which was 72.12% higher than that of unmodified biochar, and it was 3.5, 4.39 times that of traditional GF and CC. The maximum output voltage was 6.12% higher than before modification, 15.56% and 23.8% higher than traditional GF and CC anodes. GO/PANI@Biochar anode utilized the advantages of GO conductivity and biochar high biocompatibility effectively. The synergism of them can significantly improve the current and power density of MFC.

Experimental and validation with neural network time series model of microbial fuel cell bio-sensor for phenol detection

Phenol is one of the most commonly known chemical compound found as a pollutant in the chemical industrial wastewater. This pollutant has potential threat for human health and environment, as it can be easily absorbed by the skin and the mucous. Here, we prepared dual chambered microbial fuel cell (MFC) sensor for the detection of phenol. Varying concentration of phenol (100 mg/l, 250 mg/l, 500 mg/l, and 1000 mg/l) was applied as a substrate to the MFC and their change in output voltage was also measured. After adding 100 mg/l, 250 mg/l, 500 mg/l, and 1000 mg/l of phenol as sole substrate to the MFC, the maximum voltage output was obtained as 360 ± 10 mV, 395 ± 8 mV, 320 ± 7 mV, 350 ± 5 mV respectively. This biosensor was operated using industrial wastewater isolated microbes as a sensing element and phenol was used as a sole substrate. The topologies of ANN were analyzed to get the best model to predict the power output of MFCs and the training algorithms were compared with their convergence rates in training and test results. Time series model was used for regression analysis to predict the future values based on previously observed values. Two types of mathematical modeling i.e. Scaled Conjugate Gradient (SCG) algorithm and Time-series model was used with 44 experimental data with varying phenol concentration and varying synthetic wastewater concentration to optimize the biosensor performance. Both SCG and time series showing the best results with R2 value 0.98802 and 0.99115.

Effects of surface functional groups of coal-tar-pitch-derived nanoporous carbon anodes on microbial fuel cell performance

Coal tar pitch, the residue generated from distillation of coal tar, is cheap, abundant, and carbon enriched. This paper evaluates the effects of the surface modification of coal-tar pitch-derived nanoporous carbons (NPCs) as anode materials on the performance of Escherichia coli (E. coli)-based microbial fuel cells (MFCs) for the first time. The coal-tar pitch precursors are heated under N2 to 450 °C (450O) and 750 °C (750X) to obtain NPCs with different concentrations of oxygen-containing functional groups. 750X is, thereafter, doped with nitrogen atoms to generate a nitrogen-doped NPCs (750N). More biofilm is formed on the 750N anode than the 750X or 450O anode because of the higher electrical conductivity and biocompatibility of 750N. As a result, a higher power output of MFC is obtained when the 750N anode is used. The maximum power density of 750N is 3772 mW m−2, while that of 750X and 450O are 2876 mW m−2 and 3562 mW m−2, respectively, demonstrating that 750N is a potential sustainable anode material for high-performance MFC applications.