Fuel Cells For Wastewater Treatment Research Articles

Embedded Graphite and Carbon Nanofibers in a Polyurethane Matrix Used as Anodes in Microbial Fuel Cells for Wastewater Treatment.

Composites of polyurethane and graphite and polyurethane and carbon nanofibers (PU/Graphite 0.5% and PU/CNF 1%) were synthesized and used as anodes in dual-compartment microbial fuel cells (MFCs) for municipal wastewater treatment; electrical energy generation and organic matter removal were assessed. The maximum power density, coulombic efficiency and chemical oxygen demand (COD) removal efficiency in the MFCs packed with the PU/Graphite 0.5% and PU/CNF 1% composites were 232.32 mW/m3 and 90.78 mW/m3, 5.87 and 4.41%, and 51.38 and 68.62%, respectively. In addition, the internal resistance of the MFCs with the best bioelectrochemical performance (PU/Graphite 0.5%) was 1051.11 Ω. The results obtained in this study demonstrate the feasibility of using these types of materials in dual-compartment MFCs for wastewater treatment with electric power generation.

Adaptive Neuro-Fuzzy Inference System Modeling and Optimization of Microbial Fuel Cells for Wastewater Treatment

Due to their toxicity, Cr(VI) levels are subject to strict legislation and regulations in various industries and environmental contexts. Effective treatment technologies are also being developed to decrease the negative impacts on human health and the environment by removing Cr(VI) from water sources and wastewater. As a result, it would be interesting to model and optimize the Cr(VI) removal processes, especially those under neutral pH circumstances. Microbial fuel cells (MFCs) have the capacity to remove Cr(VI), but additional research is needed to enhance their usability, increase their efficacy, and address issues like scalability and maintaining stable operation. In this research work, ANFIS modeling and artificial ecosystem optimization (AEO) were used to maximize Cr(VI) removal efficiency and the power density of MFC. First, based on measured data, an ANFIS model is developed to simulate the MFC performance in terms of the Cu(II)/Cr(VI) ratio, substrate (sodium acetate) concentration (g/L), and external resistance Ω. Then, using artificial ecosystem optimization (AEO), the optimal values of these operating parameters, i.e., Cu(II)/Cr(VI) ratio, substrate concentration, and external resistance, are identified, corresponding to maximum Cr(VI) removal efficiency and power density. In the ANFIS modeling stage of power density, the coefficient-of-determination is enhanced to 0.9981 compared with 0.992 (by ANOVA), and the RMSE is decreased to 0.4863 compared with 16.486 (by ANOVA). This shows that the modeling phase was effective. In sum, the integration between ANFIS and AEO increased the power density and Cr(VI) removal efficiency by 19.14% and 15.14%, respectively, compared to the measured data.

Microbial Fuel Cell for Wastewater Treatment as Power Plant in Smart Grids: Utopia or Reality?

Microbial fuel cells (MFCs) have undergone great technological development in the last 20 years, but very little has been done to commercialize them. The simultaneous power production and wastewater treatment are features those greatly increase the interest in the use of MFCs. This kind of distributed power generation is renewable and friendly and can be easily integrated into a smart grid. However, there are some key issues with their commercialization: high construction costs, difficulty in developing high power structures, MFC lifespan, and maintaining a high level of efficiency. The objective of this article is to explore the possibilities of using MFCs in urban wastewater not only regarding the technical criteria of their application, but also mainly from an economic point of view, to determine the conditions through which the viability of the investment is ensured and the possibilities of their integration in a smart grid are identified. Initially, this article explores the implementation/configuration of a power plant with MFCs within an urban wastewater treatment plant on a theoretical basis. In addition, based on the corresponding physical quantities for urban wastewater treatment, the construction and operational costs are determined and the viability of the investment is examined based on classic economic criteria such as net present value, benefit–cost ratio, internal rate of return, and discounted payback period. Furthermore, sensitivity analysis is carried out, concerning both technical parameters, such as the percentage of organic matter removal, power density, sewage residence time, MFC efficiency, etc., and economical parameters, such as the reduction of construction costs due to change of materials, change of interest rate, and lifetime. The advantages and disadvantages of their use in smart grids is also analyzed. The results show that the use of MFCs for power generation cannot be utopian as long as they are integrated into the structure of a central wastewater treatment plant on the condition that the scale-up technical issues of MFCs are successfully addressed.

Preparation of Pt–Ru/C as an Oxygen-Reduction Electrocatalyst in Microbial Fuel Cells for Wastewater Treatment

Carbon-supported Pt–Ru alloys with a Pt/Ru ratio of 1:1 were prepared by NaBH4 reduction at room temperature. X-ray diffraction (XRD) measurements indicate that the as-prepared Pt–Ru nanoparticles had a face-centered cubic (fcc) structure. X-ray photoelectron spectroscopy (XPS) analyses demonstrate that alloying with Ru can decrease the 4f electron density of Pt, which results in a positive binding energy shift of 0.2 eV for the Pt 4f peaks. The catalytic properties of the synthesized Pt–Ru alloy catalysts were compared with those of commercial Pt/C catalysts by linear sweep voltammetry (LSV). The results show that the mass activity of the oxygen reduction reaction (ORR) is enhanced by 2.3 times as much mass activity of Pt relative to the commercial Pt/C catalyst. Single-chambered microbial fuel cell tests also confirm that the Pt–Ru alloys as cathode catalysts have better performance than that of commercial Pt/C catalysts.

(Invited) Microbial Fuel Cells for Wastewater Treatment - from Lab to Practice

Microbial Fuel Cells (MFCs) have been intensively studied as a promising technology for energy harvesting. However, in recent years it has become apparent that electricity production from MFCs may not yield energy densities comparable to chemical fuel cells or conventional batteries - but MFCs can provide sustainable and cost-effective wastewater treatment. Conventional centralized wastewater treatment is a very costly process requiring significant infrastructure and energy input. Further, water recycling from conventional wastewater treatment plants is becoming a more acceptable method to deliver clean water in drought-stricken areas, requiring even more energy and infrastructure for disinfection and distribution. In contrast to conventional wastewater treatment technologies, MFCs enable a decentralized method for wastewater treatment, water recycling, real-time monitoring and direct control of organic removal and biomass production. In addition, direct recovery of electric energy, high quality effluents and low environmental footprints can be achieved through MFC technologies. However, while MFCs hold tremendous promise, the practical application of MFC technology has not been realized due great challenges in cost, system stability and optimization – all necessary steps in technology scale up and commercialization. In this study various aspects of MFC technology development from lab prototypes to practical installations for wastewater treatment have been evaluated. An MFC installation consisting of twelve MFC single chamber reactors (Fig. 1) has been designed and explored under real environmental conditions. Each reactor has a rectangular shape with either one or two anodes, positioned at the top and the bottom of the MFC, and two gas-diffusion cathodes. The installation operates under flow through mode with swine waste used as the inoculum source (along with lagoon sediment) and feed solution. In terms of accelerated organics removal, various aspects have been addresses related to reactor design, electrode optimization, operational characteristics, cathode biofouling, biofilm development and bacterial enrichment at the anode. Each of the design aspects has been evaluated first in the lab and then transferred to the field for validation. A start up time of 5 days has been achieved with 0.55 V at 560 Ω. The long-term operation under MFC mode demonstrated 0.27 V at 22 Ω and ~1kg/m3.d COD removal. Interrupted mode of operation provided more stable MFC output and prolonged cathode life span. Figure 1

Neutral Red Immobilized Graphite Felt Anodic Microbial Fuel Cell for Wastewater Treatment and Generation of Electricity

Microbial Fuel Cell (MFC) can be a great demand for waste water treatment in future. Alternatively, the increasing demand of energy can be fulfilled by this technique in the future if the performance of MFC is improved. In this paper, a MFC was constructed by using graphite felt immobilized with neutral red as anode and a platinum coated platinum wire as cathode. Analyte used was municipal wastewater and catholyte was phosphate buffer of pH 7. The wastewater contained 1.457 mg/l of Ammonical Nitrogen, 33.363 mg/l of COD, 0.537 mg/l of total Phosphorus, 0.105 mg/l of reducing sugar and 0.139 mg/l of Nitrite nitrogen. The mixed culture of organism dominantly present in the wastewater was used in MFC. The result was found to be effective when cellulose acetate was used as membrane compared to the Nafion membrane. The COD of wastewater was reduced by 69.96% when MFC was run for five days with cellulose acetate membrane. The maximum power generated was 24.45 W/m3 when 1% H2O2 was supplied as a source of oxygen in the cathode compartment. The result indicates microbial fuel cell technology to be a new approach for wastewater treatment as it produces sustainable clean energy by minimizing COD level.

Algal-assisted Microbial Fuel Cell for Wastewater Treatment and Bioelectricity Generation

The aim of the present work was to design a self-sustainable, low-cost microbial fuel cell using a blue green algae-assisted cathode as a substitute for chemical oxidant. The idea was to utilize the oxygen produced during photosynthesis by algae as an oxidant in the cathode chamber. Results successfully demonstrated that the algae-assisted microbial fuel cell is efficient for electricity generation and chemical oxygen demand removal from wastewater. The performance of a developed microbial fuel cell resulted in a maximum current density of 149.5 mA m−2 and power density of 78.12 mW m−2. Dissolved oxygen concentration in cathode solution achieved in the range of 3.5 to 5.5 mg l−1. Furthermore, other species of algae like oil-algae can be grown in a cathode chamber, which can be used for bio-diesel production and greenhouse gas like CO2 sequestering. Further works are under progress on this aspect in our research group.

Performance of Microbial Fuel Cell for Wastewater Treatment and Electricity Generation

Renewable energy will have an important role as a resource of energy in the future. Microbial fuel cell (MFC) is a promising method to obtain electricity from organic matter and wastewater treatment simultaneously. In a pilot study, use of microbial fuel cell for wastewater treatment and electricity generation investigated. The bacteria of ruminant used as inoculums. Synthetic wastewater used at different organic loading rate. Hydraulic retention time was an effective factor in removal of soluble COD and more than 49% removed. Optimized HRT to achieve the maximum removal efficiency and sustainable operation could be regarded 1.5 and 2.5 hours. Columbic efficiency (CE) affected by organic loading rate (OLR) and by increasing OLR, CE reduced from 71% to 8%. Maximum voltage was 700mV. Since the microbial fuel cell reactor considered as an anaerobic process, it may be an appropriate alternative for wastewater treatment

Evaluation of a Fungal Strain On a Microbial Fuel Cell for Wastewater Treatment with the Presence of Azo-Dye Colorants

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Integrating Forward Osmosis into Microbial Fuel Cells for Wastewater Treatment, Water Extraction and Bioelectricity Generation

A novel osmotic microbial fuel cell (OsMFC) was developed by using a forward osmosis (FO) membrane as a separator. The performance of the OsMFC was examined with either NaCl solution or artificial seawater as a catholyte (draw solution). A conventional MFC with a cation exchange membrane was also operated in parallel for comparison. It was found that the OsMFC produced more electricity than the MFC in both batch operation (NaCl solution) and continuous operation (seawater), likely due to better proton transport with water flux through the FO membrane. Water flux from the anode into the cathode was clearly observed with the OsMFC but not in the MFC. The solute concentration of the catholyte affected both electricity generation and water flux. These results provide a proof of concept that an OsMFC can simultaneously accomplish wastewater treatment, water extraction (from the wastewater), and electricity generation. The potential applications of the OsMFC are proposed for either water reuse (linking to reverse osmosis for reconcentration of draw solution) or seawater desalination (connecting with microbial desalination cells for further wastewater treatment and desalination).

Bio-Electro-Fenton Process Driven by Microbial Fuel Cell for Wastewater Treatment

In this study, we proposed a new concept of utilizing the biological electrons produced from a microbial fuel cell (MFC) to power an E-Fenton process to treat wastewater at neutral pH as a bioelectro-Fenton (Bio-E-Fenton) process. This process can be achieved in a dual-chamber MFC from which electrons were generated via the catalyzation of Shewanella decolorationis S12 in its anaerobic anode chamber and transferred to its aerated cathode chamber equipped with a carbon nanotube (CNT)/gamma-FeOOH composite cathode. In the cathode chamber, the Fenton's reagents including hydrogen peroxide (H(2)O(2)) and ferrous irons (Fe(2+)) were in situ generated. This Bio-E-Fenton process led to the complete decolorization and mineralization of Orange II at pH 7.0 with the apparent first-order rate constants, k(app) = 0.212 h(-1) and k(TOC) = 0.0827 h(-1), respectively, and simultaneously produced a maximum power output of 230 mW m(-2) (normalized to the cathode surface area). The apparent mineralization current efficiency was calculated to be as high as 89%. The cathode composition was an important factor in governing system performance. When the ratio of CNT to gamma-FeOOH in the composite cathode was 1:1, the system demonstrated the fastest rate of Orange II degradation, corresponding to the highest amount of H(2)O(2) formed.

Conception of a Prototype Microbial Fuel Cell for Wastewater Treatment

Conception of a Prototype Microbial Fuel Cell for Wastewater TreatmentMicrobial fuel cell (MFC) is an emerging technology with multiple exciting applications in the future. Most of the research effort so far has been focused towards wastewater treatment and bioenergy recovery; however, the process of scaling-up an MFC is not straightforward due to inherent limitations. In this study, we introduce a novel prototype MFC that is one of the largest constructed so far...Author(s)Olivier LefebvreYue Pan ChengAbdullah Al-MamunZhe TangDaniel H. C. ChuaHow Yong NgSourceProceedings of the Water Environment FederationSubjectSession 15 - Microbial Fuel CellsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2009ISSN1938-6478SICI1938-6478(20090101)2009:17L.516;1-DOI10.2175/193864709793956095Volume / Issue2009 / 17Content sourceWEFTECFirst / last page(s)516 - 526Copyright2009Word count154Subject keywordsmicrobial fuel cellmodular systemscalabilityprototypepilotinternal resistance

Microbial Fuel Cells for Wastewater Treatment

In the recent years the power densities of Microbial Fuel Cells (MFCs) have increased by orders of magnitude upon decreasing the internal ohmic resistance of the system. With the ohmic resistance of the MFC systems no longer a dominant issue, identification of other intrinsic resistances is the need of the hour. Electrochemical impedance spectroscopy (EIS) was used to study the impedance behavior of a microbial fuel cell (MFC) during initial biofilm growth in an acetate-fed, two-chamber MFC system with ferricyanide in the cathode using mixed culture of bacteria obtained from activated sludge as the bio-catalyst. Results showed that the kinetics of anode bio-electrochemical reactions were sluggish, thereby contributing to the majority of the polarization loss. Also the anode charge transfer resistance was found to vary during the initial biofilm growth indicating a direct correlation between the microbial processes and the system performance.

Microbial Fuel Cells for Wastewater Treatment

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