scholarly journals Novel graphite rod electrode modified with iron-functionalized nanozeolite for efficient wastewater treatment by microbial fuel cells

2021 ◽  
Vol 4 (01) ◽  
pp. 26-35
Author(s):  
Mostafa Hassani ◽  
Mohsen Zeeb ◽  
Amirhossein Monzavi ◽  
Zahra Khodadadi ◽  
Mohammad Reza Kalaee

Microbial fuel cells (MFCs) are a green and efficient approach to treat wastewater and generate energy. According to the present research, a novel MFC fabricate based on graphite rod electrodes (GRE). The surface of this cathode was modified with iron-functionalized ZSM-5 nanozeolite. The characterization of Iron doping in nanozeolite structure and electrode surface modification were obtained by XRD and EDX analyzes, respectively. Chemical analysis of square wave (Sqw) and cyclic voltammetry (CV) determined for all of three graphite electrodes (G, G-Z and G-Z/Fe) with higher efficiency. Morover, the comparison of experimental results from 72-hour fuel cell steering was evaluated and showed that the G-Z/Fe graphite electrodes has maximum efficiency and effectiveness. Thus, the efficiency of fuel cell output current and residual chemical oxygen demand removal with this electrode increased up to 21.8% and 36.9%, respectively. The effiucient recovery for the modification of the graphite electrode was achieved due to increasing of the specific surface area, the active sites of functionalized nanozeolite and the elevation in the electrical conductivity through the presence of iron particles doped in the ZSM-5/Fe nanocatalyst structure. Therefore, the G-Z/Fe cathode can be used as a favorite electrode for the construction of MFCs based on GRE .

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 206
Author(s):  
Jiao Wang ◽  
Xiaohui Zhang ◽  
Yang Li ◽  
Peng Liu ◽  
Xiaochen Chen ◽  
...  

Sugar has the potential to create enough energy to power mobile electronics. Various sugar-powered fuel cells have been reported, however, most of them used pure glucose as substrate and enzymes/noble metals as catalysts. In this work, an alkaline fuel cell with cheap catalysts were constructed, and different sweet drinks were used as fuels for power generation. The influence of different substrates on the electrochemical performance was characterized under the controlled conditions. Our experimental results showed that the fuel cell fueled with carbonated soft drinks had the best performance under the conditions of 99.95 g/L chemical oxygen demand and 3M KOH. The power densities of the fuel cell fueled with different substrates decreased in the order of Pepsi (33.41 W/m2) > Sprite (28.38 W/m2) > apple juice (20.63 W/m2) > Coca (16.31 W/m2) > pear juice (15.31 W/m2) > orange juice (12.75 W/m2), which was consistent with linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) analysis. This is the first report on alkaline fuel cell (AFC) performance using different sweet drinks as substrate. These values are more than 10 times higher than those of reported microbial fuel cells. Our findings demonstrated that sweet drinks fueled alkaline fuel cells can be a promising energy source for low-power electronics.


2007 ◽  
Vol 73 (16) ◽  
pp. 5347-5353 ◽  
Author(s):  
Hanno Richter ◽  
Martin Lanthier ◽  
Kelly P. Nevin ◽  
Derek R. Lovley

ABSTRACT The ability of Pelobacter carbinolicus to oxidize electron donors with electron transfer to the anodes of microbial fuel cells was evaluated because microorganisms closely related to Pelobacter species are generally abundant on the anodes of microbial fuel cells harvesting electricity from aquatic sediments. P. carbinolicus could not produce current in a microbial fuel cell with electron donors which support Fe(III) oxide reduction by this organism. Current was produced using a coculture of P. carbinolicus and Geobacter sulfurreducens with ethanol as the fuel. Ethanol consumption was associated with the transitory accumulation of acetate and hydrogen. G. sulfurreducens alone could not metabolize ethanol, suggesting that P. carbinolicus grew in the fuel cell by converting ethanol to hydrogen and acetate, which G. sulfurreducens oxidized with electron transfer to the anode. Up to 83% of the electrons available in ethanol were recovered as electricity and in the metabolic intermediate acetate. Hydrogen consumption by G. sulfurreducens was important for ethanol metabolism by P. carbinolicus. Confocal microscopy and analysis of 16S rRNA genes revealed that half of the cells growing on the anode surface were P. carbinolicus, but there was a nearly equal number of planktonic cells of P. carbinolicus. In contrast, G. sulfurreducens was primarily attached to the anode. P. carbinolicus represents the first Fe(III) oxide-reducing microorganism found to be unable to produce current in a microbial fuel cell, providing the first suggestion that the mechanisms for extracellular electron transfer to Fe(III) oxides and fuel cell anodes may be different.


2020 ◽  
Vol 202 ◽  
pp. 08007
Author(s):  
Wahyu Zuli Pratiwi ◽  
Hadiyanto Hadiyanto ◽  
Purwanto Purwanto ◽  
Muthi’ah Nur Fadlilah

Microalgae-Microbial Fuel Cells (MMFCs) are very popular to be used to treat organic waste. MMFCs can function as an energy-producing wastewater pre-treatment system. Wastewater can provide an adequate supply of nutrients, support the large capacity of biofuel production, and can be integrated with existing wastewater treatment infrastructure. The reduced content of Chemical Oxygen Demand (COD) is one way to measure the efficiency of wastewater treatment. MMFCs reactors are made in the form of two chambers (anode and cathode) both of which are connected by a salt bridge. Tofu wastewater as an anode and Spirulina sp as a cathode. To improve MFCs performance which is to obtain maximum COD removal and electricity generation, nutrient NaHCO3 as the nutrient carbon source for Spirulina sp was varied. The system running phase on 12 days. The results were Spirulina sp treated with MFCs technology has better growth than non-MFCs. The MMFC generated a maximum power density of 21.728 mW/cm2 and achieved 57.37% COD removal. These results showed that the combined process was effective in treating tofu wastewater.


Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.


Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 379
Author(s):  
Ignacio T. Vargas ◽  
Natalia Tapia ◽  
John M. Regan

During the last decade, bioprospecting for electrochemically active bacteria has included the search for new sources of inoculum for microbial fuel cells (MFCs). However, concerning power and current production, a Geobacter-dominated mixed microbial community derived from a wastewater inoculum remains the standard. On the other hand, cathode performance is still one of the main limitations for MFCs, and the enrichment of a beneficial cathodic biofilm emerges as an alternative to increase its performance. Glucose-fed air-cathode reactors inoculated with a rumen-fluid enrichment and wastewater showed higher power densities and soluble chemical oxygen demand (sCOD) removal (Pmax = 824.5 mWm−2; ΔsCOD = 96.1%) than reactors inoculated only with wastewater (Pmax = 634.1 mWm−2; ΔsCOD = 91.7%). Identical anode but different cathode potentials suggest that differences in performance were due to the cathode. Pyrosequencing analysis showed no significant differences between the anodic community structures derived from both inocula but increased relative abundances of Azoarcus and Victivallis species in the cathodic rumen enrichment. Results suggest that this rarely used inoculum for single-chamber MFCs contributed to cathodic biofilm improvements with no anodic biofilm effects.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1803 ◽  
Author(s):  
Yuko Goto ◽  
Naoko Yoshida

Conventional aerobic treatment of swine wastewater, which generally contains 4500–8200 mg L−1 of organic matter, is energy-consuming. The aim of this study was to assess the application of scaled-up microbial fuel cells (MFCs) with different capacities (i.e., 1.5 L, 12 L, and 100 L) for removing organic matter from swine wastewater. The MFCs were single-chambered, consisting of an anode of microbially reduced graphene oxide (rGO) and an air-cathode of platinum-coated carbon cloth. The MFCs were polarized via an external resistance of 3–10 Ω for 40 days for the 1.5 L-MFC and 120 days for the 12L- and 100 L-MFC. The MFCs were operated in continuous flow mode (hydraulic retention time: 3–5 days). The 100 L-MFC achieved an average chemical oxygen demand (COD) removal efficiency of 52%, which corresponded to a COD removal rate of 530 mg L−1 d−1. Moreover, the 100 L-MFC showed an average and maximum electricity generation of 0.6 and 2.2 Wh m−3, respectively. Our findings suggest that MFCs can effectively be used for swine wastewater treatment coupled with the simultaneous generation of electricity.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4712
Author(s):  
Dawid Nosek ◽  
Agnieszka Cydzik-Kwiatkowska

Development of economical and environment-friendly Microbial Fuel Cells (MFCs) technology should be associated with waste management. However, current knowledge regarding microbiological bases of electricity production from complex waste substrates is insufficient. In the following study, microbial composition and electricity generation were investigated in MFCs powered with waste volatile fatty acids (VFAs) from anaerobic digestion of primary sludge. Two anode sizes were tested, resulting in organic loading rates (OLRs) of 69.12 and 36.21 mg chemical oxygen demand (COD)/(g MLSS∙d) in MFC1 and MFC2, respectively. Time of MFC operation affected the microbial structure and the use of waste VFAs promoted microbial diversity. High abundance of Deftia sp. and Methanobacterium sp. characterized start-up period in MFCs. During stable operation, higher OLR in MFC1 favored growth of exoelectrogens from Rhodopseudomonas sp. (13.2%) resulting in a higher and more stable electricity production in comparison with MFC2. At a lower OLR in MFC2, the percentage of exoelectrogens in biomass decreased, while the abundance of genera Leucobacter, Frigoribacterium and Phenylobacterium increased. In turn, this efficiently decomposed complex organic substances, favoring high and stable COD removal (over 85%). Independent of the anode size, Clostridium sp. and exoelectrogens belonging to genera Desulfobulbus and Acinetobacter were abundant in MFCs powered with waste VFAs.


Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1383 ◽  
Author(s):  
Liping Fan ◽  
Junyi Shi ◽  
Tian Gao

Proton exchange membrane is an important factor affecting the power generation capacity and water purification effect of microbial fuel cells. The performance of microbial fuel cells can be improved by modifying the proton exchange membrane by some suitable method. Microbial fuel cells with membranes modified by SiO2/PVDF (polyvinylidene difluoride), sulfonated PVDF and polymerized MMA (methyl methacrylate) electrolyte were tested and their power generation capacity and water purification effect were compared. The experimental results show that the three membrane modification methods can improve the power generation capacity and water purification effect of microbial fuel cells to some extent. Among them, the microbial fuel cell with the polymerized MMA modified membrane showed the best performance, in which the output voltage was 39.52 mV, and the electricity production current density was 18.82 mA/m2, which was 2224% higher than that of microbial fuel cell with the conventional Nafion membrane; and the COD (chemical oxygen demand) removal rate was 54.8%, which was 72.9% higher than that of microbial fuel cell with the conventional Nafion membrane. Modifying the membrane with the polymerized MMA is a very effective way to improve the performance of microbial fuel cells.


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