scholarly journals Preparation and Analysis of Ni–Co Catalyst Use for Electricity Production and COD Reduction in Microbial Fuel Cells

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1042 ◽  
Author(s):  
Paweł P. Włodarczyk ◽  
Barbara Włodarczyk

Microbial fuel cells (MFCs) are devices than can contribute to the development of new technologies using renewable energy sources or waste products for energy production. Moreover, MFCs can realize wastewater pre-treatment, e.g., reduction of the chemical oxygen demand (COD). This research covered preparation and analysis of a catalyst and measurements of changes in the concentration of COD in the MFC with a Ni–Co cathode. Analysis of the catalyst included measurements of the electroless potential of Ni–Co electrodes oxidized for 1–10 h, and the influence of anodic charge on the catalytic activity of the Ni–Co alloy (for four alloys: 15, 25, 50, and 75% concentration of Co). For the Ni–Co alloy containing 15% of Co oxidized for 8 h, after the third anodic charge the best catalytic parameters was obtained. During the MFC operation, it was noted that the COD reduction time (to 90% efficiency) was similar to the reduction time during wastewater aeration. However, the characteristic of the aeration curve was preferred to the curve obtained during the MFC operation. The electricity measurements during the MFC operation showed that power equal to 7.19 mW was obtained (at a current density of 0.47 mA·cm−2).

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.


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.


2018 ◽  
Vol 400 ◽  
pp. 441-448 ◽  
Author(s):  
Clement A. Cid ◽  
Andrew Stinchcombe ◽  
Ioannis Ieropoulos ◽  
Michael R. Hoffmann

Scientifica ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Irina V. Khilyas ◽  
Anatoly A. Sorokin ◽  
Larisa Kiseleva ◽  
David J. W. Simpson ◽  
V. Fedorovich ◽  
...  

Bioelectrochemical systems such as microbial fuel cells (MFCs) are promising new technologies for efficient removal of organic compounds from industrial wastewaters, including that generated from swine farming. We inoculated two pairs of laboratory-scale MFCs with sludge granules from a beer wastewater-treating anaerobic digester (IGBS) or from sludge taken from the bottom of a tank receiving swine wastewater (SS). The SS-inoculated MFC outperformed the IGBS-inoculated MFC with regard to COD and VFA removal and electricity production. Using a metagenomic approach, we describe the microbial diversity of the MFC planktonic and anodic communities derived from the different inocula. Proteobacteria (mostly Deltaproteobacteria) became the predominant phylum in both MFC anodic communities with amplification of the electrogenic genusGeobacterbeing the most pronounced. Eight dominant and three minor species ofGeobacterwere found in both MFC anodic communities. The anodic communities of the SS-inoculated MFCs had a higher proportion ofClostridiumandBacteroidesrelative to those of the IGBS-inoculated MFCs, which were enriched withPelobacter. The archaeal populations of the SS- and IGBS-inoculated MFCs were dominated byMethanosarcina barkeriandMethanothermobacter thermautotrophicus, respectively. Our results show a long-term influence of inoculum type on the performance and microbial community composition of swine wastewater-treating MFCs.


2021 ◽  
Vol 775 ◽  
pp. 145904
Author(s):  
Jaecheul Yu ◽  
Younghyun Park ◽  
Evy Widyaningsih ◽  
Sunah Kim ◽  
Younggy Kim ◽  
...  

2014 ◽  
Vol 157 ◽  
pp. 114-119 ◽  
Author(s):  
Tyler Huggins ◽  
Heming Wang ◽  
Joshua Kearns ◽  
Peter Jenkins ◽  
Zhiyong Jason Ren

2016 ◽  
Vol 53 (5) ◽  
pp. 43-53
Author(s):  
G. Klāvs ◽  
A. Kundziņa ◽  
I. Kudrenickis

Abstract Use of renewable energy sources (RES) might be one of the key factors for the triple win-win: improving energy supply security, promoting local economic development, and reducing greenhouse gas emissions. The authors ex-post evaluate the impact of two main support instruments applied in 2010-2014 – the investment support (IS) and the feed-in tariff (FIT) – on the economic viability of small scale (up to 2MWel) biogas unit. The results indicate that the electricity production cost in biogas utility roughly corresponds to the historical FIT regarding electricity production using RES. However, if in addition to the FIT the IS is provided, the analysis shows that the practice of combining both the above-mentioned instruments is not optimal because too high total support (overcompensation) is provided for a biogas utility developer. In a long-term perspective, the latter gives wrong signals for investments in new technologies and also creates unequal competition in the RES electricity market. To provide optimal biogas utilisation, it is necessary to consider several options. Both on-site production of electricity and upgrading to biomethane for use in a low pressure gas distribution network are simulated by the cost estimation model. The authors’ estimates show that upgrading for use in a gas distribution network should be particularly considered taking into account the already existing infrastructure and technologies. This option requires lower support compared to support for electricity production in small-scale biogas utilities.


2017 ◽  
Vol 69 ◽  
pp. 346-352 ◽  
Author(s):  
Benyi Xiao ◽  
Meng Luo ◽  
Xiao Wang ◽  
Zuoxing Li ◽  
Hong Chen ◽  
...  

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.


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