Benthic Microbial Fuel Cells Research Articles

Biogalvanic cathodic protection applied to a large-scale laboratory pilot concrete pier: influence of the bioanodic surface, tidal variations and temperature

The management of corrosion in reinforced concrete (RC) structures is crucial for addressing the challenges posed by aging infrastructure, particularly in marine environments where the aggressiveness of seawater can severely impact durability. This study explores a novel approach known as BioGalvanic Cathodic Protection (BGCP), inspired by Benthic Microbial Fuel Cells, for the electrochemical maintenance of RC exposed to marine corrosion. BGCP utilizes electroactive microorganisms naturally present in marine sediments to form bioanodes on conductive materials, which provide protective electrical currents to partially submerged RC structures. A pilot study involved a 3-meter-high concrete pier, which was partially immersed in natural seawater and sediments with embedded bioanodes. The current distribution from the BGCP system to the steel was monitored for over a year under various configurations, including changes in steel surface area and the number of bioanodes, while simulating tidal variations and monitoring ambient temperature. Results indicated that BGCP effectively demonstrated cathodic prevention for passive steel, with improved performance observed when multiple bioanodes were utilized. Indeed, the total current density received by the steel was in the range of [-0.2;-2 mA/m2] at all times. The current distribution varied with tidal changes, peaking at the air/water interface. A notable correlation emerged between temperature and current output, suggesting better performance at elevated temperatures. Although CP has not yet been achieved on actively corroding steel, BGCP offers significant potential for delaying corrosion initiation through the development of a self-sustaining and environmental-friendly technology.

Experimental Proof of Principle of 3D-Printed Microfluidic Benthic Microbial Fuel Cells (MBMFCs) with Inbuilt Biocompatible Carbon-Fiber Electrodes.

Microbial fuel cells (MFCs) represent a promising avenue for sustainable energy production by harnessing the metabolic activity of microorganisms. In this study, a novel design of MFC-a Microfluidic Benthic Microbial Fuel Cell (MBMFC)-was developed, fabricated, and tested to evaluate its electrical energy generation. The design focused on balancing microfluidic architecture and wiring procedures with microbial community dynamics to maximize power output and allow for upscaling and thus practical implementation. The testing phase involved experimentation to evaluate the performance of the MBMFC. Microbial feedstock was varied to assess its impact on power generation. The designed MBMFC represents a promising advancement in the field of bioenergy generation. By integrating innovative design principles with advanced fabrication techniques, this study demonstrates a systematic approach to optimizing MFC performance for sustainable and clean energy production.

Stimulating bioelectric generation and recovery of toxic metals through benthic microbial fuel cell driven by local sago (Cycas revoluta) waste.

Benthic microbial fuel cell (BMFC) is the most promising type of bioelectrochemical approach for producing electrons and protons from natural organic waste. In the present work, a single-chamber BMFC was used, containing sago (Cycas revoluta) waste as the organic feed for microorganisms. The local wastewater was supplemented with heavy metal ions (Pb2+, Cd2+, Cr3+, Ni2+, Co2+, Ag+, and Cu2+) and used as an inoculation source to evaluate the performance of BMFC against the toxic metal remediations. According to the experimental results, the maximum power density obtained was 42.55 mW/m2 within 25days of the BMFC operation. The maximum remediation efficiency of the metal ion removal from the wastewater was found to be 99.30% (Ag+). The conductive pili-type bacteria species (Acinetobacter species, Leucobacter species, Bacillus species, Proteus species. and Klebsiella pneumoniae) were found in the present study during isolation and identification processes. This study's multiple parameter optimization revealed that pH 7 and room temperature is the best condition for optimal performance. Finally, this study included the mechanism, future recommendations, and concluding remarks.

Application of Benthic Microbial Fuel Cells in Systems of Year-Round Monitoring of Water Environment Parameters

The bioelectrogenic activity of sediments of natural microbial association of the Peter’s Bay of Japanese sea research was performed in a year-round experiment with parallel temperature, illumination and water electrical conductivity monitoring by means of benthic microbial fuel cell (MFC) and automatic online-monitoring. Several variants of underwater devices, including benthic microbial fuel cells, monitoring water environment sensor,information collection and transmission systems, have been developed. This device make electrical voltage up to 216 mV, specific power up to 239 mW/m2. Electrogenic activity of natural microflora depends on water temperature and reach maximum on summer with temperature about 20–25°C. The introduction of toxicants in form as hydrocarbons and cadmium into the sluge led to the suppression of microbial electrogenesis. However the introduction of inductor substances of microbial sulfidogenesis led to the stimulation of microbial electrogenesis. The possibility of functioning of the benthic MFC in the field of the Peter’s Great Bay in various climatic periods is shown. It is shown that such experimental devices serve as a basis for autonomous stations monitoring the state of the aquatic environment for a long time and in a wide range of conditions change. Thus, automatic registration of temperature, illumination and salinity of water with a frequency of 48 times a day was carried out for 13 months (11/28/2019–12/31/2020). The electrogenic activity of this microbiota upon MFC scaling can potentially become a new renewable energy source for low-power marine electronics, including those used in mariculture.

Biomass and domestic waste: a potential resource combination for bioenergy generation and water treatment via benthic microbial fuel cell.

The benthic microbial fuel cell (BMFC) is one of the most efficient types of bioelectrochemical fuel cell systems. Modern bioelectrochemical fuel cells have several drawbacks, including an unstable organic substrate and a microorganism-unfriendly atmosphere. The recent literature to encounter such issues is one of the emerging talks. Researchers are focusing on the utilization of biomass and waste to encounter such challenges and make the technique more feasible at the pilot scale. This study investigated the combination of local bakery waste as an organic substrate with lignocellulosic biomass material. The whole experiment was conducted for 45days. At an external resistance of 1000 ῼ and an internal resistance of 677 ῼ, the power density was found to be 3.51 mW/m2. Similarly, for Pb2+, Cd2+, Cr3+, Ni2+, and Co2+, the degradation efficiency was 84.40%, 81.21%, 80%, 89.50%, and 86.0%, respectively. The bacterial identification results showed that Liquorilactobacillus nagelii, Proteus mirabilis, Pectobacterium punjabense, and Xenorhabdus thuongxuanensis are the most prominent species found on anode biofilm. The method of electron generation in this study, which includes the degradation of metal ions, is also well described. Lastly, optimising the parameters showed that pH 7 provides a feasible environment for operation. A few future suggestions for practical steps are enclosed for the research community.

Dual Role of Sugarcane Waste in Benthic Microbial Fuel to Produce Energy with Degradation of Metals and Chemical Oxygen Demand

One of the most advanced systems of microbial fuel cells is the benthic microbial fuel cell (BMFC). Despite several developments, this strategy still has a number of significant flaws, such as instable organic substrate. Waste material (sugarcane) is used as a substrate in this work to address the organic substrate instability. The process was operated continuously for 70 days. A level of 300 mV was achieved after 33 days of operation, while the degradation efficiencies of Pb (II), Cd (II), and Cr (III) were more than 90%. More than 90% of the removed chemical oxygen demand (COD) was also recorded. The measured power density was 3.571 mW/m2 at 1000 external resistance with 458 internal resistance. This demonstrates that electrons are effectively transported throughout the operation. The Bacillus strains are the most dominant bacterial community on the surface of the anode. This research’s mechanism, which involves metal ion degradation, is also explained. Finally, parameter optimization indicated that pH 7 works efficiently. In addition to that, there are some future perspectives and concluding remarks enclosed.

A novel design for the development of deployable benthic microbial fuel cells using PPy-Fe2O3 coated multi-anode system

Benthic microbial fuel cells (BMFCs) provide a reliable option to replace toxic batteries for powering naval sensors. However, reliability can be increased by providing a stable architectural framework and electrode setup to increase the power by overcoming the existing resistances and limitations, which have already been mentioned in the works of literature. In this work, we have tried to shortlist the current problem by defining a new architectural framework and enhancing the power by designing a PPy-Fe2O3 coated multi-electrode system while maintaining a low footprint. A deployable BMFC was tested as a potential power generation source in marine sediment. A tubular column consisting of anodes at different positions in a vertical manner was employed in the sediment. Performances of the developed BMFC were evaluated by measuring open circuit potential and power generation. Maximum power of 1.5 mW was obtained when the anodes were combined altogether. The experiment continued for two months without any extra supplements. A voltage booster was successfully designed using an integrated circuit that further enhanced the input voltage from 0.7 V to 4.57 V. This study can be implemented as a progressive approach to develop marine-based microbial fuel cells further.

Benthic microbial fuel cell systems for marine applications

Energy sources that may be converted to electric power are elusive at the seafloor. This communication describes the design of a compact benthic microbial fuel cell (BMFC) and a power management platform (PMP) that have been used to recharge lithium-ion batteries with energy harvested in situ from biomass enclosed in the BMFC's anode chamber. The primary power produced was typically between 5 and 50 mW with 42% of the energy transferred to battery storage. The batteries in turn were used to sustain environmental sensors and acoustic communication devices during three experiments in contrasting marine locations. The programmable PMP permitted control of sensor duty cycles and monitoring of BMFC performance. One of the experiments occurred at an ocean depth of 580 m for 1,045 days. It suggested a need for longer lasting biomass supplies to sustain elevated power levels beyond 2–3 years. Based on the lessons learned from these experiments, we conclude that BMFC systems are now sufficiently mature to be applied within marine observing networks. They represent an alternative power source that may be integrated readily with many kinds of innovative sensors.

Local fruit wastes driven benthic microbial fuel cell: a sustainable approach to toxic metal removal and bioelectricity generation.

The present work focused on the utilization of three local wastes, i.e., rambutan (Nephelium lappaceum), langsat (Lansium parasiticum), and mango (Mangifera indica) wastes, as organic substrates in a benthic microbial fuel cell (BMFC) to reduce the cadmium and lead concentrations from synthetic water. Out of the three wastes, the mango waste promoted a maximum current density (87.71mA/m2) along with 78% and 80% removal efficiencies for Cd2+ and Pb2+, respectively. The bacterial identification proved that Klebsiella pneumoniae, Enterobacter, and Citrobacter were responsible for metal removal and energy generation. In the present work, the BMFC mechanism, current challenges, and future recommendations are also enclosed.

Electricity generation in simulated benthic microbial fuel cell with conductive polyaniline-polypyrole composite hydrogel anode

As a sustainable and eco-friendly technology, the benthic microbial fuel cell (BMFC) has been emerged as alternative and potential approach to recover electrical energy by microorganisms, but lower power density and poor long-term life hinder their practical application. Modification of anodic materials is an efficient strategy to solve this problem. Here, a conductive and biocompatible hydrogel electrode, polyaniline-polypyrole-CNTs-Fe3O4 (PANI-PPy-CNTs-Fe3O4) is prepared and applied as anode in a simulated BMFC. The maximum power density of the BMFC with PANI-PPy-CNTs-Fe3O4 hydrogel anode (5901.49 mW/m3) is 1.33, 2.15 and 2.06 times higher than that of PANI-PPy (4413.03 mW/m3), PANI and PPy anodes (2737.12 and 2859.53 mW/m3), respectively. The charge transfer resistance of quaternary hydrogel bioanode in BMFC (3.922 Ω) is much lower than that of the PANI (8.682 Ω), PPy (8.262 Ω) and PANI-PPy (5.772 Ω) hydrogel bioanodes. Moreover, the extracellular electron transfer ability is also enhanced on the composite hydrogel anode, which also exhibits the high biomass. High-throughput sequencing technology indicates that the synergistic effect of bacteria on the quaternary hydrogel made full use of organic matter as available fuel to enable a high electricity-generation anode. Such foregoing mainly ascribed to the composite hydrogel keep the high biocompatibility from components, while the addition of CNTs and Fe3O4 dramatically decreases the internal resistance and provides more electrochemical active surface area on basis of macroporous 3D hydrogel structure. This work explores the composite hydrogel used as anodes to construct high-performance BMFC and provides significant information for the applications of actual BMFCs in the future.

Electrochemical evaluation of lab-scale chamber benthic microbial fuel cell

Benthic microbial fuel cell (BMFC) utilizes naturally available exoelectrogens and organic matter present in the sediment to produce electrical energy. The practical limitation of BMFC is maybe due to the mass transport losses. Therefore, practical implications were deduced from two different types of lab-scale BMFC i.e. chamber-BMFC (C-BMFC) with pumping to avoid the accumulation and to increase diffusion rate; and sediment-BMFC (S-BMFC). Further, to identify sources of impedance losses, effect of the sediment height over anode was investigated in sterile media (sediment and seawater). In C-BMFC, anodes of equal size (3 cm × 3 cm) were deployed inside the chamber with two different volumes as 50 mL (50:3C) and 180 mL (180:3C). In S-BMFC anodes of two different sizes as 3 cm × 3 cm (3S) and 6 cm × 6 cm (6S) were deployed inside sediment. In-situ electrochemical techniques were implemented in BMFC to estimate diffusion impedance. The diffusion coefficient was found to be increasing with the sediment height in sterile media. Maximum power density generated by 6S, 3S, 50:3C, and 180:3C was 181, 201, 335.51, and 421.02 mW m−2 respectively. Impedance data shows microbial consortia play a vital role in the mass transport phenomena electrochemical diffusion in BMFC.

Bioelectricity production and xylene biodegradation through double chamber benthic microbial fuel cells fed with sugarcane waste as a substrate

Xylene, a recalcitrant compound present in wastewater from activities of petrochemical and chemical industries causes chronic problems for living organisms and the environment. Xylene contaminated wastewater may be biodegraded through a benthic microbial fuel cell (BMFC) as seen in this study. Xylene was oxidized into intermediate 3-methyl benzoic acid and entirely converted into non-toxic carbon dioxide. The highest voltage of the BMFC reactor was generated at 410 mV between 23 and 90 days when cell potential was 1 kΩ. The reactor achieved a maximum power density of about 63 mW/m2, and a current of 0.4 mA which was optimized from variable resistance (20 Ω - 1 kΩ). However, the maximum biodegradation efficiency of the BMFC was at 87.8%. The cyclic voltammetry curve helped to determine that the specific capacitance was 0.124 F/g after 30 days of the BMFC operation. Furthermore, the fitting equivalent circuit was observed with the help of Nyquist plot for calculating overall internal resistance of 65.82 Ω on 30th day and 124.5 Ω on 80th day. Staphylococcus edaphicus and Staphylococcus sparophiticus were identified by 16S rRNA sequencing as the dominant species in the control and BMFC electrode, presumably associated with xylene biodegradation.

Enhanced benzene bioremediation and power generation by double chamber benthic microbial fuel cells fed with sugarcane waste as a substrate

Benzene in wastewater poses severe toxic effects on living organisms and the environment. For this study, the possibility of using benthic microbial fuel cells (BMFC) for bioremediation of benzene using sugar cane waste as a substrate, while simultaneously producing bioenergy was studied. A BMFC is a membrane-less microbial fuel cell. Benzene was oxidised into intermediate benzoic acid then completely converted to carbon dioxide. The maximum potential was calculated using a multimetre, while current density and power density through the polarization curve. UV–visible spectroscopy and cyclic voltammetry were used to determine bioremediation efficiency and capacitance respectively. Electrochemical impedance spectroscopy determined the overall internal resistance and microbiological analysis revealed the bacteria present. Voltage of 430 mV was generated between 40 and 80 days at an external resistance of 1 kΩ. Within 40 days, a maximum power density of 24.2 mW/m2 and current density of 95 mA/m2 was generated. Also, the bioremediation efficiency of benzene was 82.3%. The optimum oxidation and reduction curve at day 40 was 0.1 V (forward peak) and −0.4 V (reverse peak) with a capacitance of 0.00004 F/g. The fitting equivalent circuit analysis measured an overall internal resistance (161.51 Ω) with the help of Nyquist plot. The SEM images showed holes in an irregular manner distributed over the electrode's surface. These holes represent excellent behaviour for developing biofilm. The 16S rDNA pyro-sequencing results identified Pseudomonas sp. and Bacillus sp. This is the first report of sugar cane waste as a substrate in a BMFC to bioremediate benzene along with power generation. These results showed that the BMFC could be used for power generation and benzene bioremediation.

Proof-of-concept for a novel application for in situ Microfluidic Benthic Microbial Fuel Cell device (MBMFC)

Benthic Microbial Fuel Cells (BMFC) are an environmentally compatible, carbon-neutral energy resource that can operate in marine sediments and provide underwater power. BMFC performance is dependent on both biological factors and engineering materials and design. The biological component, being less predictable in nature, is typically controlled in laboratory settings to optimize fuel cell performance. However, this study seeks to improve the in situ performance of BMFC power production through augmenting engineering design factors. Decreasing the distance between the electrogenic bacteria and the capture electrode could be a solution to improve the BMFC performance for in situ anode devices. To evaluate this, a layered microfluidic elastomeric on quartz chip was fabricated to confine the bacteria within ~90 µm from the chrome microelectrode matrix patterned onto the chip’s quartz substrate. The device served as a Microfluidic Benthic anode connected with a carbon cloth cathode to form a Microfluidic Benthic Microbial Fuel Cell (MBMFC). The MBMFC units were placed in sediment under flow-through laboratory conditions and power generation was recorded. Typical membrane-less microbial fuel cells in flow-through seawater laboratories or in situ conditions, have power production ranges 3–40 mW/m2 with steady state power averaging 8–10 mW/m2. The results from these MBMFC devices demonstrated power density of 30–120 mW/m2 with steady state production levels 20–80 mW/m2. Conservatively that is 3 times higher than previously recorded BMFC units in sediments from San Diego Bay, and an 8-fold improvement in steady-state production. However, in consideration of the immediate ramp-up time and steady-state power production, it is a marked improvement to traditional in situ BMFC performance. This serves as a proof-of-concept for a scalable in situ microfluidic device that could serve as a future potential power source. The presented approach may offer a testing platform for further optimizations in MBMFC research and development.

Electricity generation and heavy metal remediation by utilizing yam (Dioscorea alata) waste in benthic microbial fuel cells (BMFCs)

In the present study, yam (Dioscorea alata) waste is used in benthic microbial fuel cells (BMFCs) to remediate heavy metals (Pb2+, Cd2+, Cr3+) from the metals-supplemented pond water. The obtained energy efficiency was 0.0744 mW/m2 while the targeted heavy metals remediation results are very encouraging. Within 30 days of the BMFCs operation, the remediation efficiency of Pb2+ was 90.14 %, Cd2+ was 88.00 % and Cr3+ showed 90.34 %. The Bacillus, Klebsiella, and Enterobacter species, which are responsible for metal remediation and energy generation, were identified during the biological tests. Additionally, pH and temperature optimizations were carried out to predict the optimum conditions for the industrial-scale BMFCs operation. Lastly, the BMFCs mechanism and future recommendations are included.

Advancement in Benthic Microbial Fuel Cells toward Sustainable Bioremediation and Renewable Energy Production.

Anthropogenic activities are largely responsible for the vast amounts of pollutants such as polycyclic aromatic hydrocarbons, cyanides, phenols, metal derivatives, sulphides, and other chemicals in wastewater. The excess benzene, toluene and xylene (BTX) can cause severe toxicity to living organisms in wastewater. A novel approach to mitigate this problem is the benthic microbial fuel cell (BMFC) setup to produce renewable energy and bio-remediate wastewater aromatic hydrocarbons. Several mechanisms of electrogens have been utilized for the bioremediation of BTX through BMFCs. In the future, BMFCs may be significant for chemical and petrochemical industry wastewater treatment. The distinct factors are considered to evaluate the performance of BMFCs, such as pollutant removal efficiency, power density, and current density, which are discussed by using operating parameters such as, pH, temperature and internal resistance. To further upgrade the BMFC technology, this review summarizes prototype electrode materials, the bioremediation of BTX, and their applications.

Cellulose Derived Graphene/Polyaniline Nanocomposite Anode for Energy Generation and Bioremediation of Toxic Metals via Benthic Microbial Fuel Cells.

Benthic microbial fuel cells (BMFCs) are considered to be one of the eco-friendly bioelectrochemical cell approaches nowadays. The utilization of waste materials in BMFCs is to generate energy and concurrently bioremediate the toxic metals from synthetic wastewater, which is an ideal approach. The use of novel electrode material and natural organic waste material as substrates can minimize the present challenges of the BMFCs. The present study is focused on cellulosic derived graphene-polyaniline (GO-PANI) composite anode fabrication in order to improve the electron transfer rate. Several electrochemical and physicochemical techniques are used to characterize the performance of anodes in BMFCs. The maximum current density during polarization behavior was found to be 87.71 mA/m2 in the presence of the GO-PANI anode with sweet potato as an organic substrate in BMFCs, while the GO-PANI offered 15.13 mA/m2 current density under the close circuit conditions in the presence of 1000 Ω external resistance. The modified graphene anode showed four times higher performance than the unmodified anode. Similarly, the remediation efficiency of GO-PANI was 65.51% for Cd (II) and 60.33% for Pb (II), which is also higher than the unmodified graphene anode. Furthermore, multiple parameters (pH, temperature, organic substrate) were optimized to validate the efficiency of the fabricated anode in different environmental atmospheres via BMFCs. In order to ensure the practice of BMFCs at industrial level, some present challenges and future perspectives are also considered briefly.

Insights into Advancements and Electrons Transfer Mechanisms of Electrogens in Benthic Microbial Fuel Cells.

Benthic microbial fuel cells (BMFCs) are a kind of microbial fuel cell (MFC), distinguished by the absence of a membrane. BMFCs are an ecofriendly technology with a prominent role in renewable energy harvesting and the bioremediation of organic pollutants through electrogens. Electrogens act as catalysts to increase the rate of reaction in the anodic chamber, acting in electrons transfer to the cathode. This electron transfer towards the anode can either be direct or indirect using exoelectrogens by oxidizing organic matter. The performance of a BMFC also varies with the types of substrates used, which may be sugar molasses, sucrose, rice paddy, etc. This review presents insights into the use of BMFCs for the bioremediation of pollutants and for renewable energy production via different electron pathways.

New design of benthic microbial fuel cell for bioelectricity generation: Comparative study

Benthic microbial fuel cells (BMFCs) are the potential sources for energy generation in which the chemical energy stored in the bonds between organic and non-organic materials are turned into electricity using microorganisms as the catalysts. In this study, new anodic chamber is fabricated for BMFC. The environmental conditions similar to those of Caspian Sea water have been applied to an experimental setup. The output power density in the BMFC has been measured and evaluated using various electrodes including graphite plate (GP), carbon cloth (CC) and granular activated carbon (GAC) at various distances 10, 20 and 50 cm, in different current and time steps. Based on the obtained results, too close or too far distance between the electrodes leads to an increase in the internal resistance and reduces the performance of the cell. In this regard, the optimized distance for the electrodes has been found to be 20 cm. The maximum power density of the GAC electrode before using the anodic chamber was 92.85 mW/m2 in current density of 324.67 mA/m2. This value has reached 170.02 mW/m2 and 422.02 mA/m2 after deployment in the anodic chamber under the same environmental conditions, which indicates that the maximum power density experienced an approximately double increase compared to the previous state.

Impact of sediment parameters in the prediction of benthic microbial fuel cell performance.

The benthic microbial fuel cell (BMFC) is a promising technology for harvesting renewable energy from marine littoral environments. The scientific community has researched BMFC technology for well over a decade, but the in situ performance remains challenging. To address this challenge, BMFC power experiments were performed on sediment collected from San Diego Bay (CA, USA), La Spezia (Italy) and Honolulu (HI, USA) in the ever-changing littoral environment. Analysis of BMFC laboratory data found the power density varied substantially across 11 sites in San Diego Bay. In addition, data from experiments repeated at four locations in San Diego Bay showed significant differences between experiments performed in 2014, 2016 and 2019. Multivariable linear analysis showed BMFC 90 day cumulative power density was positively correlated with the total organic carbon (p < 0.05) and negatively correlated with the black carbon in the sediment (p < 0.05). Regression coefficients trained on the San Diego Bay data from 2014 facilitated accurate predictions of BMFC performance in 2016 and 2019. The modeling paradigm accurately explained variations in BMFC power performance in La Spezia and showed sediment parameters can impact BMFC performance differently across geographic regions. The results demonstrate a great potential to use sediment parameters and statistical modeling to predict BMFC power performance prior to deployment in oceanographic environments, thereby reducing cost, work force and resources.