Performance Of Sediment Microbial Fuel Cells Research Articles

Cross-linked Polypyrrole@Co3O4 for boosting bioenergy output and regulating electroactive microflora in sediment microbial fuel cells

Sediment microbial fuel cell (SMFC) has been regarded as a promising device for simultaneously bioenergy supply and bioremediation, but the low power density and less research on bioremediation still hinders its practical application. As the carrier of exoelectrogens, anode is closely related to above characteristics of SMFC. Thus, the modification of anode is a reliable way to improve SMFC performance. In this paper, the graphite plate (GP) is modified with polypyrrole/Co3O4 composite (PPy@Co3O4) by electrodeposition to obtain a high capacitive and conductive electrode. SMFC equipped with PPy@Co3O4-GP shows maximum power density of 247.89 mW/m2, nearly 1.94 times higher than blank control group (127.61 mW/m2). The microflora analysis exhibits that PPy@Co3O4-GP has great screening ability for electroactive microbes, and forming electroactive functional microflora involved with Sulfurovum and Streptococcus. The results of sediment composition show that PPy@Co3O4-GP has good bioremediation potential. This work provides an easy and reliable surface modification method for the development of high-performance bioenergy harvesting and bioremediation SMFC anodic materials.

Sediment microbial fuel cell with biochar-modified cathode for remediation of black-odorous water sediments and analysis of microbial community

Sediment microbial fuel cells (SMFCs) generate electricity through microbial degradation of organic matter in sediments, and the cathode catalyst used for the oxygen reduction reaction is a key factor affecting the performance of SMFCs. To improve power production in SMFCs and remediate black-odorous water sediments, this study modifies the cathode carbon felt of the SMFC system with Enteromorpha prolifera (EP) biochar with high N and P content. The study demonstrated that the SMFC system with the modified cathode carbon felt (C-800℃/CF) exhibited superior power generation capabilities, achieving a maximum power density of 219.44 mW·m−2. Over 25 days of operation, the anode biofilm effectively degraded around 78.15% of total organic carbon, 79.55% of acid volatile sulfide, 74.78% of total nitrogen, 80.58% of ammonia nitrogen, and 77.46% of total phosphorus in the sediment. In addition, microbial community analysis showed that functional bacteria Thiobacillus, Acidaminobacter, Sulfurimonas, Bacteroidetes_vadinHA17, and Sideroxydans were the dominant genera in the anode biofilm.

Effect of NH2-MWCNTs/CF anodes on the power generation performance of SMFCs

The carbon nanotube-modified anodes have been widely recognized as one of the most effective methods to improve the conductivity of the anode and enhance the performance of microbial fuel cells. And there are few studies on the effect of amino-functionalized carbon nanotube-modified anodes on the performance of sediment microbial fuel cells (SMFCs) systematically. In this paper, we prepared amino-functionalized carbon nanotube-modified electrodes and constructed SMFCs using them to study the effect of amino-functionalized carbon nanotubes on the power generation performance of SMFCs. The results showed that the highest output voltage of NH2-functionalized multi-walled carbon nanotube (NH2-MWCNT)-modified carbon felt (CF) SMFCs (529.15 mV) was significantly higher than that of CF (474.5 mV). And the power density of SMFCs with 10% NH2-MWCNTs/CF reached a maximum of 58.3 mW/m3. There are because NH2-MWCNTs surface has a larger specific surface area and a porous structure, enhancing electron conduction pathway helps to improve the conductivity of the anode. Therefore, the modification of CF surfaces with NH2-MWCNTs can be used to improve the interfacial properties and positively enhance the power generation performance of SMFCs. This study provides a novel and effective approach to enhance the performance of SMFCs and contributes to the international research on carbon nanotube-modified anodes for energy and environmental applications.

Effect of Electro-Oil Acclimation of an Indigenous Strain on the Performance of Sediment Microbial Fuel Cells (SMFC)

Sediment microbial fuel cell (SMFC) is a type of MFC without a proton exchange membrane. However, SMFC have had problems with low-power production performance. In this paper, the effects of native bacteria (K1) in oily sludge and their electro-oil-induced domestication on the power generation and oil removal performance of SMFC were studied. The results showed that K1 belonged to Ochrobactrum intermedium. During the domestication process, an upward trend was shown in the OD600 and ORP values in the culture medium, and it grown best at 0.7 V. Ochrobactrum intermedium K1 significantly increased the average output voltage, electromotive force, and maximum power density of SMFC and reduced the apparent internal resistance of the battery. The maximum power density was 169.43 mW/m3, which was 8.59 times higher than that of the control group. Ochrobactrum intermedium K1 improved the degradation of crude oil by SMFC. Ochrobactrum intermedium K1 enhanced the degradation of high-carbon alkanes and even-carbon alkanes in n-alkanes. Cyclic voltammetry and chronoamperometry tests showed that after acclimation, Ochrobactrum intermedium K1 improved the extracellular electron transfer efficiency (EET) mediated by c-Cyts and flavin by increasing the surface protein redox potential.

Simultaneous landfill leachate treatment and electricity production by sediment microbial fuel cell

The sediment microbial fuel cell (SMFC) is a new technology that uses exoelectrogenic bacteria and organic compounds to transform chemical energy into electrical energy. The application of SMFC technology is gaining popularity since it can simultaneously reduce contaminants in wastewater and generate electricity. An SMFC performance is mainly governed by the kinetics of the electrodes within the fuel cell, of which the materials that make up the electrodes significantly impact their performance. The objective of the ongoing investigation was to study the performance of three types of electrodes for minimizing pollutants from landfill leachate wastewater while also generating electrical energy. Sediment and leachate samples were taken from the Regional Landfill wastewater treatment facility in Blang Bintang, Aceh Besar, the Province of Aceh. Three transparent acrylic reactors with a length, width, and height of 45 cm, 20 cm, and 12 cm, respectively, were employed in this experiment. The electrode materials utilized in this study were zinc (Zn), copper (Cu), and iron (Fe), with each electrode having a surface area of 124 cm2. Temperature, pH, voltage, and carbonaceous compound removal measured as COD were used to assess the SMFC performance. The study results showed that the temperature and pH of the three reactors have a similar trend, and the values are not much different at 24.36±0.25°C and 9±0.03, respectively. The reactor installed with Cu electrode produced the maximum electrical voltage of 470 mV, whereas those with Fe and Zn had the highest voltages of 107 mV and 23 mV, respectively. The percentage of COD removal for reactors equipped with Zn, Cu, and Fe electrodes was 40.70%, 41.09%, and 41.23%, respectively. Although the COD removal by each reactor of different electrode materials did not show a significant difference, the reactor with Cu electrode gave better performance when viewed from the electrical voltage.

Anode modification of sediment microbial fuel cells (SMFC) towards bioremediating mariculture wastewater

Remediation of mariculture wastewater is of great practical importance. In this study, sediment microbial fuel cells (SMFCs) were adopted and carbon felt anodes were modified to enhance COD and ammonia removal in mariculture system. The results showed that the SMFC anode with 5 % (w/w) graphene oxide (GO) coating performed best in pollutants removal and electricity generation. The maximum power density approached 132 mW/m2, nearly 4.5 times higher than the unmodified anode. The removal efficiency of COD and ammonia reached 82.1 % and 95.8 % respectively, both improved compared with the control and chemical modification. The modified anode effectively enriched the electrogenic Sulfurovum and Lactobacillus and thus led to a significant improvement in the electrochemical performance of SMFC. This study demonstrates the successful application of SMFCs with GO modified anodes in the in-situ removing pollutants and SMFCs present obvious remediation potential on the contaminated mariculture inhabitant.

Enhancing pollutant removal and electricity generation in Sediment Microbial Fuel Cell with nano zero-valent iron

A nano zero-valent iron (NZVI) was added into sediments to enhance the capacities of sediment microbial fuel cells (SMFCs) for pollutant removal and electricity generation. Open and closed circuits were applied to confirm the impact of NZVI on the pollutant removal performance of SMFCs. The operation of SMFCs in a closed circuit with 0.06% NZVI produced a current density of 340.8 mA/m 2 . Adding 0.6% NZVI to closed-circuit SMFCs reduced hydrogen sulfide from 12.5 mg/L to 0 mg/L. Moreover, adding NZVI to closed-circuit SMFCs reduced phosphate concentration from 49 mg/L to 11 mg/L. With the same amount of NZVI, the pollutant removal in a closed circuit was higher than that in an open circuit because of the electricity flow at SMFCs. In conclusion, addition of NZVI to SMFCs effectively enhanced the produced current density and reduced the concentrations of hydrogen sulfide and phosphate in sediments. • Addition of NZVI to the anode chamber enhanced electricity production in SMFCs. • The higher current density of 340.8 mA/m2 in SMFC with addition 0.06% of NZVI . • Addition of 0.6% of NZVI reduced phosphate and hydrogen sulfide in sediments. • Excessive NZVI reduces electricity production in SMFCs.

Small boreholes embedded in the sediment layers make big difference in performance of sediment microbial fuel cells: Bioelectricity generation and microbial community

The practical applications of sediment microbial fuel cells (SMFCs) are limited by their low power densities. In this work, a novel SMFC configuration with a cylindrical borehole embedded in the sediment layer is proposed with expectations of reducing internal resistance, enhancing mass transfer, and accordingly increasing power density. Two types of boreholes with same diameter of 10 cm, but different depths of 3 cm and 6 cm are constructed in SMFCs (SMFC-3 and SMFC-6). Results demonstrate that SMFC-3 produces the highest maximum power density (65.6 mW/m2), which is 25.5% and 65.6% higher than that in SMFC-6 (52.3 mW/m2) and the control SMFC (SMFC-C, 39.4 mW/m2), respectively. The improved power performance in SMFC-3 is mainly due to the greatly reduced internal resistance. Compared to SMFC-6, the higher power density in SMFC-3 is also due to the relatively low overlying water pH values, providing suitable pH condition for cathodic reactions. Microbial community analyses demonstrate that Alphaproteobacteria and Gammaproteobacteria are major contributors to the bioelectricity, and that electroactive species enriched on the top and bottom sides of anodes are significantly different. Generally, embedding a small borehole into the sediment layer is an easy-to-implement and cost-effective strategy for improving the power performance of SMFCs.

Electricity generation potential of sewage sludge in sediment microbial fuel cell using Ti–TiO2 electrode

AbstractThe aim of this study is to increase the electricity generation capacity of sediment microbial fuel cell (SMFC) using sewage sludge as a substrate source in anode media via an attractive electrode material. For this purpose, several electrochemical and molecular techniques have been employed to evaluate the performance of SMFC. The max power density and charge transfer resistance of SMFC running on sewage sludge were 187 mW/m2 and 84.7 Ω, respectively. The polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE) analysis indicated that bacteria in anode biofilm belonged to the Clostridia, d‐proteobacteria, g‐proteobacteria, and b‐proteobacteria. Scanning electron microscopy and fluorescence in situ hybridization observations demonstrated that a viable biofilm was formed on the anode surface and the abundance of bacteria was significantly higher than archaea. Consequently, this study showed that sewage sludge could be used as a substrate in the anode media of SMFC for producing high power density.

Carbon nanomaterial-modified graphite felt as an anode enhanced the power production and polycyclic aromatic hydrocarbon removal in sediment microbial fuel cells

Sediment microbial fuel cells (SMFCs) can be used to generate electricity and remove organic contaminants. For electricity generation and contaminant removal, the anode material is one of important factors influencing the performance of SMFCs. In this study, graphene (GR), graphene oxide (GO) and carbon nanotubes (CNTs) were applied to modify the graphite felt (GF) anode in SMFCs during 110 d operation. An economical and easy modification method with the carbon nanomaterials was applied. The carbon nanomaterials increased the electrochemically active surface areas and biomass content of the anodes and correspondingly effectively enhanced the generation of electricity and the removal rates of loss on ignition (LOI) and polycyclic aromatic hydrocarbons (phenanthrene and pyrene). During the steady period from 50 d to 110 d, the GO-SMFCs favored the enrichment of EAB and thus output the highest voltages of 30.60–48.61 mV. The GR-SMFCs and GO-SMFCs generated high electric power of approximate 0.98 ± 0.14 kJ and 0.87 ± 0.04 kJ, followed by CNT-SMFCs (0.57 ± 0.06 kJ) and GF-SMFCs (0.49 ± 0.07 kJ) during the 110 d operation. The PAH degradation was not directly related to the electric current in the SMFCs. Near the anodes, the order of the phenanthrene removal rates was CNT-SMFCs (78.1%) > GR-SMFCs (73.0%) ≈ GO-SMFCs (71.2%) > GF-SMFCs (45.6%), and the order of the pyrene removal rates was GO-SMFCs (69.6%) ≈ GR-SMFCs (68.2%) ≈ CNT-SMFCs (66.7%) > GF-SMFCs (42.3%). The three carbon nanomaterials increased the microbial community diversity and slightly changed the microbial community distribution of biofilms on the anodes. Correlation analysis indicated that the degradation of phenanthrene was positively correlated with the abundances of Pseudomonas, Thauera, Diaphorobacter, Tumebacillus and Lysobacter. Pyrene degradation was strongly correlated with LOI degradation.

Burial depth of anode affected the bacterial community structure of sediment microbial fuel cells

Sediment microbial fuel cells (SMFCs) are attractive devices to in situ power environmental monitoring sensors and bioremediate contaminated soils/sediments. Burial depth of the anode was verified to affect the performance of SMFCs. The present research evaluated the differences in microbial community structure of anodic biofilms located at different depth. It was demonstrated that both microbial diversity and community structure of anodic biofilms were influenced by the depth of anode location. Microbial diversity decreased with increased anodic depth. The number of the operational taxonomic units (OTUs) was determined as 1438 at the anode depth of 5 cm, which reduced to 1275 and 1005 at 10 cm and 15 cm, respectively. Cluster analysis revealed that microbial communities of 5 cm and 10 cm were clustered together, separated from the original sediment and 15 cm. Proteobacteria was the predominant phylum in all samples, followed by Bacteroidetes and Firmicutes. Beta-and Gamma-proteobacteria were the most abundant classes. A total of 23 OTUs showed high identity to 16S rRNA gene of exoelectrogens such as Geobacter and Pseudomonas. The present results provided insights into the effects of anode depth on the performance of SMFC from the perspectives of microbial community structure.

Assessment of Electron Transfer Mechanisms during a Long-Term Sediment Microbial Fuel Cell Operation

The decentralized production of bioelectricity as well as the bioremediation of contaminated sediments might be achieved by the incorporation of an anode into anaerobic sediments and a cathode suspended in the water column. In this context, a sediment microbial fuel cell microcosm was carried out using different configurations of electrodes and types of materials (carbon and stainless steel). The results showed a long-term continuous production of electricity (>300 days), with a maximum voltage of approximately 100 mV reached after ~30 days of operation. A twofold increase of voltage was noticed with a twofold increase of surface area (~30 mV to ~60 mV vs. 40 cm2 to 80 cm2), while a threefold increase was obtained after the substitution of a carbon anode by one of stainless steel (~20 mV to ~65 mV vs. 40 cm2 to 812 cm2). Cyclic voltammetry was used to evaluate sediment bacteria electroactivity and to determine the kinetic parameters of redox reactions. The voltammetric results showed that redox processes were limited by the diffusion step and corresponded to a quasi-reversible electron charge transfer. These results are encouraging and give important information for the further optimization of sediment microbial fuel cell performance towards the long-term operation of sediment microbial fuel cell devices.

Enhanced performance of sediment microbial fuel cell by immobilization of Shewanella oneidensis MR-1 on an anode surface

The anodic microbial community especially relative abundance of exoelectrogens is crucial for performance enhancement of sediment microbial fuel cell (SMFC). In this study, Shewanella oneidensis MR-1 was immobilized on an active carbon fiber anode and the SMFC's performance was evaluated. The maximum power density of SMFC with immobilized strain MR-1 (SMFC-ImSW) displayed 61.0 mW/m2, and SMFC with conventional bioaugmentation (SMFC-SW) and no treatment (SMFC-CK) of strain MR-1 obtained 11.1 and 2.4 mW/m2, respectively. The chemical oxygen demand removal efficiency of SMFC-ImSW was 14.2% and 24.2% higher than SMFC-SW and SMFC-CK groups, respectively. Furthermore, the organics removal efficiencies of sediment were also increased in SMFC-Imsw. GFP-tagging and RT-PCR results showed that strain MR-1 was colonized on the anode biofilm of SMFC-ImSW. Cyclic voltammetry and Electrochemical impedance spectroscopy results showed that higher redox potential and charge transfer efficiency presented with immobilized strain MR-1. MiSeq sequencing results showed that Sphaerochaetaceae and Marinilabiaceae were also enriched on the anode biofilm, which are related to power generation. These results demonstrated that immobilized bioaugmentation is an ideal approach to improve SMFC performance.

An Approach to Predicting Sediment Microbial Fuel Cell Performance in Shallow and Deep Water

Here we present an approach to predicting sediment microbial fuel cell performance based on environmental conditions. Sediment total organic carbon and water temperature were found to be important determinants in predicting the power output from microbial fuel cells in shallow sediments (<100 m) in San Diego. We extrapolated data from the in situ San Diego experiments to predict MFC performance in shallow sediments in other locations, namely the Gulf of Mexico and the Yellow Sea. Finally, using laboratory data of MFC performance in deep water (~1000 m) sediment samples, we extend our predictions to ocean sediments worldwide. We predict low power output from the deep sea (microwatts) relative to the shallow sediments (milliwatts), and attribute that to a possible lack of electrogenic bacteria in the sediments, lower sediment permeability, or a greater proportion of refractory organic matter reaching the bottom.

Scale up sediment microbial fuel cell for powering Led lighting

Sediment microbial fuel cells (SMFCs) are expected to be utilized as a sustainable power source for remote environmental observing 30 day’s investigations of experiment to understand the long-term performance of SMFCs. The point of this investigation is to increase power generation, 8 individual sediment microbial fuel cells is stacked together either in series or in hybrid connection. Two combinations, of the hybrid connection, are proving to be the more effective one, step-up both the voltage and current of the framework, mutually. Polarization curve tests are done for series and hybrid connected sediment microbial fuel cell. The maximum study state voltage and current are obtained 8.150V and 435.25µA from series and 4.078V and 870.75µA hybrid connected SMFC. This study suggests that power of SMFC scale-up by connecting series and hybrid for practical use of the device.Article History: Received : September 26th 2017; Received: December 24th 2017; Accepted: January 4th 2018; Available onlineHow to Cite This Article: Prasad, J and Tripathi, R.K. (2018) Scale Up Sediment Microbial Fuel Cell For Powering Led Lighting. International Journal of Renewable Energy Development, 7(1), 53-58.https://doi.org/10.14710/ijred.7.1.53-58

Exposing effect of comb-type cathode electrode on the performance of sediment microbial fuel cells

Sediment microbial fuel cells (SMFCs) are an innovative, green technology with great potential, and they utilize a voltage drop of redox potential between aerobes and anaerobes to produce electricity and degrade organic wastewater. However, the power performance and degradation rate in SMFCs are limited by the low concentration of dissolved oxygen on the cathode. Therefore, in this study, SMFCs with comb-type cathode electrodes with carbon cloths exposed partly to air and embedded partly in the reactor substrate were designed and operated. They were utilized for enhancing the power density and the effect of three different exposed areas of cathode electrode for improving transfer of oxygen. Results showed that the power density reached 3.77×10−2mW/m2 for 75% of the (MA75) exposed area, which was 1.93times than that of 50% of the (MA50) exposed area and 6.44times than that of 0% (i.e., completely immersed; MA0) exposed area. These results indicated that the exposed area of the cathode electrode had a positive effect on the power performance of SMFCs and would reduce the impedance of the cathode. These findings would apparently offer useful information on the feasibility of SMFCs for wastewater treatment applications in the future.

Autonomous Device for Evaluating the Field Performance of Microbial Fuel Cells in Remote Areas

The performance of sediment microbial fuel cells (SMFCs) in the field must be evaluated prior to their being relied on as a power source for sensor networks. Currently, the ability to perform such evaluation is limited. The goal of this work was to develop an autonomous, battery-powered, low-cost device (a remote sediment microbial fuel cell tester, or RSMFCT) that can evaluate the field performance of SMFCs charging capacitors in remote areas. The developed RSMFCT allows an SMFC to charge a capacitor between preset charge and discharge potentials and monitors anode and cathode potentials, capacitor potential, and temperature. The RSMFCT was tested at a remote location in the Hot Lake Research Natural Area, near Oroville,WA, USA and used to evaluate the optimum conditions for operating an SMFC. Using the recorded data, the average power and frequency of cycle were determined. We found that SMFCs deployed in Hot Lake operated optimally when charging a 5-F capacitor from 300 mV to 400 mV. Under these conditions, the SMFCs produced an average daily power of 10.28 μW and required an average capacitor charging time of 3.08 hours. We conclude that the RSMFCT is practical for: 1) determining the optimum operation parameters, those that maximize the power output of SMFCs in field operation, and 2) reliably incorporating individual SMFCs as power sources for remote sensor networks by allowing the prediction of their power output and frequency of charge cycles.

Assessment of the performance of SMFCs in the bioremediation of PAHs in contaminated marine sediments under different redox conditions and analysis of the associated microbial communities

The biodegradation of naphthalene, 2-methylnaphthalene and phenanthrene was evaluated in marine sediment microbial fuel cells (SMFCs) under different biodegradation conditions, including sulfate reduction as a major biodegradation pathway, employment of anode as terminal electron acceptor (TEA) under inhibited sulfate reducing bacteria activity, and combined sulfate and anode usage as electron acceptors. A significant removal of naphthalene and 2-methylnaphthalene was observed at early stages of incubation in all treatments and was attributed to their high volatility. In the case of phenanthrene, a significant removal (93.83±1.68%) was measured in the closed circuit SMFCs with the anode acting as the main TEA and under combined anode and sulfate reduction conditions (88.51±1.3%). A much lower removal (40.37±3.24%) was achieved in the open circuit SMFCs operating with sulfate reduction as a major biodegradation pathway. Analysis of the anodic bacterial community using 16S rRNA gene pyrosequencing revealed the enrichment of genera with potential exoelectrogenic capability, namely Geoalkalibacter and Desulfuromonas, on the anode of the closed circuit SMFCs under inhibited SRB activity, while they were not detected on the anode of open circuit SMFCs. These results demonstrate the role of the anode in enhancing PAHs biodegradation in contaminated marine sediments and suggest a higher system efficiency in the absence of competition between microbial redox processes (under SRB inhibition), namely due to the anode enrichment with exoelectrogenic bacteria, which is a more energetically favorable mechanism for PAHs oxidation than sulfate.

Evaluation of long-term performance of sediment microbial fuel cells and the role of natural resources

Sediment microbial fuel cells (SMFCs) are expected to be used as a renewable power source for remote environmental monitoring; therefore, evaluation of their long-term power performance is critical for their usability. In this paper, we present novel data needed to understand the long-term performance of SMFCs. We used 3-D Microemulsion (3DMe)™ doped anodes, which slowly release lactate and its fermented products. During our tests, anode-limited SMFCs with and without 3DMe-doped anodes were operated for more than 18months with a load simulating a sensor operation. We found that doping an anode with an electron donor reduced startup time and increased maximum power (55±2μW compared to 46±2μW) in the control systems. We found that the long-term steady power performance is approximately 33% of the maximum power (∼18μW). Finally, our small-sized SMFCs generated higher power densities than those in the literature (28mW/m2 versus 4mW/m2). Using electron donor doped anodes can be practical when a short startup time and initial high power are needed. However, if long-term power is critical, the addition of an electron donor does not provide a practical advantage. In addition, in long-term operation enrichment of the anode surface with electrochemically active bacteria does not provide any advantage.

Organic content influences sediment microbial fuel cell performance and community structure

This study constructed sediment microbial fuel cells (SMFCs) with different organic loadings without the amendment of external substrates, and it investigated how such variation affects electricity generation and microbial community structure. Results found sediment characteristics significantly influenced SMFC performance and appropriate organic content is important to maintain stable power outputs. SMFCs with loss of ignition (LOI) of 5% showed the most reliable performance in this study, while high organic content (LOI 10–16%) led to higher but very unstable voltage output because of biogas accumulation and worm activities. SMFCs with low organic content (1–3%) showed low power output. Different bacterial communities were found in SMFCs shown various power generation performance even those with similar organic contents. Thermodesulfovibrionaceae was found closely related to the system startup and Desulfobulbaceae showed great abundance in SMFCs with high power production.