Electricity generation and wastewater treatment using microbial fuel cells with graphite and aluminum electrodes

Abstract

A microbial fuel cell (MFC) is a system that can integrate electricity generation and, at the same time, contribute to decontaminating wastewater, becoming an eco-friendly technology with the environment. In this research, microbial fuel cells with graphite and aluminum electrodes were used at different sizes: 9, 25 and 64 cm 2 , and a wastewater sample obtained from a rural location in Peru was used as substrate. The MFCs parameters of voltage, current and conductivity were monitored for 12 days, for the generation of electricity; and the parameters of Chemical Oxygen Demand (COD), Thermotolerant Coliforms, Turbidity and pH, for wastewater treatment. The MFCs with electrodes of 64 cm 2 were the ones that had the highest efficiency in the production of electricity, because they generated higher voltage, current and conductivitythroughout the days evaluated, with peaks of 0.22 V, 0.08 mA and 1.05 mS/cm, respectively. Likewise, a reduction in the content of COD, Thermotolerant Coliforms and Turbidity of the substrate used (70, 73 and 36%) was achieved, while the pH remained slightly stable, with values from 7.39 to 6.49 during the days evaluated. The MFCs are a promising approach to a sustainable future in which energy can be generated from the use of household wastewater, while simultaneously treating these effluents.

Activated Carbon Electrodes for Bioenergy Production in Microbial Fuel Cells Using Synthetic Wastewater as Substrate

“…The voltage values obtained are higher than those reported by Bose et al (2023) where they used wastewater from the sugarcane industry in MFC with biomass-derived activated carbon as the cathode and pretreated carbon wire-based brush as the anode and managed to produce maximum voltage peaks of 870 ± 20 mV [44], and Agüero-Quiñones et al (2022), who used municipal wastewater in MFC-SC with aluminum as the cathode and graphite as the anode, generating maximum values of 220 mV. Compared to our research, it may be due to the fact that the aluminum electrodes used do not have as good conductive properties as the zinc or copper used as connectors [45]. Figure 3b shows the values of electric current the cells produce during monitoring.…”

Cadmium and COD Removal from Municipal Wastewater Using Chlorella sp. Biomass in Microbial Fuel Cells

“…Other investigations also showed a decrease in current in the last few days; for example, Commault et al (2017) reported a reduction in current due to a decrease in microbial activity or a decrease in the efficiency of electron transfer in the biofilm [51]. Likewise, Rojas-Flores et al ( 2023) mention that as the organic matter in the medium decreases, there will be a decrease in electrons, which brings a decrease in the generation of electric current [52].…”