Generation of Electricity Through Papaya Waste at Different pH

Abstract

A large amount of fruit waste is being a great environmental and social problem due to a lack of adequate storage. Among the most abundant waste is papaya, due to its high consumption in various varieties. These wastes can generate bioelectricity through organic waste, being an important parameter the pH. In this research, low-cost laboratory-scale microbial fuel cells were fabricated, using papaya waste as fuel at different pH (4, 5.73, 7, and 9) to obtain the optimum operating pH. It was possible to observe the maximum values ​​of electric current and voltage of 17.97 mA and 1.02 V on days 16 and 14, in the cell with pH 7; while the cell with pH was the one that showed the lowest values. The electrical conductivity values ​​increased from the first day, observing a maximum peak of 172.50 mS/cm for the cell with pH 7. However, the internal resistance values ​​were low, the maximum value being for the cell with pH 4 (234.61 ± 34 Ω) and the minimum for the cell with pH 7 (46.543 ± 3.6 Ω). In the same way, the maximum power density was for the cell with pH 7 of approximately 645.74 ± 33.64 mW/cm2 and a current density of 5.42 A/cm2.

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

“…Figure 4b shows the power density (PD) values as a current density (DC) function, observing a maximum power density of 208.14 ± 17 mW/cm 2 and a maximum current density of 5.03 A/cm 2 . It can be observed in the graphs that the power density reaches a maximum value and subsequently presents a decrease due to the operability of the operating time and also due to the reduction in the organic matter available in the medium [54]. In addition, the values of DP and DC depend on the rate of degradation of the organic energy of the substrates by the microbial community, on the external operating conditions [55], as well as on the internal resistance of the MFCs, due to the fact that a higher R int hinders the flow of electrons through the system [56].…”