Microbial Fuel Cell with Ni–Co Cathode Powered with Yeast Wastewater

Abstract

Wastewater originating from the yeast industry is characterized by high concentration of pollutants that need to be reduced before the sludge can be applied, for instance, for fertilization of croplands. As a result of the special requirements associated with the characteristics of this production, huge amounts of wastewater are generated. A microbial fuel cell (MFC) forms a device that can apply wastewater as a fuel. MFC is capable of performing two functions at the same time: wastewater treatment and electricity production. The function of MFC is the production of electricity during bacterial digestion (wastewater treatment). This paper analyzes the possibility of applying yeast wastewater to play the function of a MFC (with Ni–Co cathode). The study was conducted on industrial wastewater from a sewage treatment plant in a factory that processes yeast sewage. The Ni–Co alloy was prepared by application of electrochemical method on a mesh electrode. The results demonstrated that the use of MFC coupled with a Ni–Co cathode led to a reduction in chemical oxygen demand (COD) by 90% during a period that was similar to the time taken for reduction in COD in a reactor with aeration. The power obtained in the MFC was 6.1 mW, whereas the volume of energy obtained during the operation of the cell (20 days) was 1.27 Wh. Although these values are small, the study found that this process can offer an additional level of wastewater treatment as a huge amount of sewage is generated in the process. This would provide an initial reduction in COD (and save the energy needed to aerate wastewater) as well as offer the means to generate electricity.

Renewable Energy and EU 2020 Target for Energy Efficiency in the Czech Republic and Slovakia

“…Apart from the traditional renewables there are also some carbon-based alternatives to oil (e.g., methane hydrates and the conversion of coal into methane gas, or the use of oil reservoirs and shale oil), but other interesting options present themselves too [39][40][41]. One of them is the microbial fuel cells (MFCs) that convert biochemical to electrical energy [42][43][44][45][46][47][48]. MFCs can be used in biomass-based energy production, even though a plethora of technical challenges has to be solved before they will be practical for renewable energy production [49][50][51].…”

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

“…A copper mesh was used as the electrode to apply the catalyst (i.e., Ni-Co alloy). The electrolyte for alloying mainly consisted of a mixture of NiSO 4 and CoSO 4 [7,76]. The electrochemical deposition was carried out at temperatures of 293-323 K, at a current density of 1-3 A•dm −2 , and at pH 2.0-5.5 [7].…”

“…Microbial fuel cells (MFCs) are a technology of electric energy generation using organic matter contained in wastewater [1,2]. Thus, this technology allows the production of energy from waste products (e.g., wastewater, also industry wastewater) [1,[3][4][5][6][7][8][9]. Moreover, MFCs allow for wastewater pretreatment, e.g., reduction of the chemical oxygen demand (COD) concentration.…”

“…However, greater progress in the development of this technology was only achieved in the 1960s [11][12][13]. Because of the increasing pollution of the environment, research on MFC technology resumed in the 1990s [14][15][16], but real development of these technology has only happened in recent years [1][2][3][4][5][6][7][17][18][19][20][21][22][23][24][25].…”

“…The lowest parameters during MFC operation were obtained using carbon cloth as electrodes. However, it was found that it was also possible to use metal electrodes (also as metal electrodes with metal catalysts) as the cathodes of microbial fuel cells [1,7,8,22,41,57,58]. Nickel is also characterized by good catalytic properties.…”