Golden Berry Waste for Electricity Generation

Abstract

The environmental problems caused by the excessive use of fossil fuels for electricity generation have led to the development of new technologies. Microbial fuel cells constitute a technology that uses organic sources for electricity generation. This research gives a novel means of using Golden Berry waste as fuel for electricity generation through microbial fuel cells made at low cost, achieving current and voltage peaks of 4.945 ± 0.150 mA and 1.03 ± 0.02 V, respectively. Conductivity values increased up to 148 ± 1 mS/cm and pH increased up to 8.04 ± 0.12 on the last day. The internal resistance of cells was 194.04 ± 0.0471 Ω, while power density was 62.5 ± 2 mW/cm2 at a current density of 0.049 A/cm2. Transmittance peaks of the Fourier-transform infrared (FTIR) spectrum showed a decrease when comparing the initial and final spectra, while the bacterium Stenotrophomonas maltophilia was molecularly identified with an identity percentage of 99.93%. The three cells connected in series managed to generate 2.90 V, enough to turn on a TV remote control. This research has great potential to be scalable if it is possible to increase the electrical parameters, generating great benefits for companies, farmers, and the population involved in the production and marketing of this fruit.

Increase in Electrical Parameters Using Sucrose in Tomato Waste

“…Many microorganisms that generate electricity use carbohydrates and different types of compounds for their proliferation, which is why there would be a direct relationship where, when increasing the values of the voltage and electric current, it would be due to the increase in the percentage of sucrose [27,28]. It has been observed in some works of the literature that the use of metallic materials produces high values of currents and voltage, but it is also counterproductive for the proliferation of microorganisms and therefore for the generation of electric currents [25,29]. Figure 2c shows the monitored pH values of the microbial fuel cells for thirty days, demonstrating that the values increased from the first day to the last, although these increases were slight in all the MFCs that were kept in the acidic region naturally, without adding chemical compounds.…”

“…The generated voltage and current values were monitored using a multimeter (Prasek Premium PR-85) for 30 days with an external resistance of 100 Ω, while the current density (CD) and the power density (PD) were calculated using the method of Segundo et al (2022), where the A (area) of the cathode had an approximate value of 78.54 cm 2 and external resistances (R ext .) of 0.3 ± 0.1, 0.6 ± 0.18, 1 ± 0.3, 1.5 ± 0.31, 3 ± 0.6, 10 ± 1.3, 20 ± 6.5, 50 ± 8.7, 60 ± 8.2, 100 ± 9.3, 120 ± 9.8, 220 ± 13, 240 ± 15.6, 330 ± 20.3, 390 ± 24.5, 460 ± 23.1, 531 ± 26.8, 700 ± 40.5, and 1000 ± 50.6 Ω [25]. The changes in conductivity (CD-4301 conductivity meter) and pH (Oakton Series 110 pH-meter) were also measured.…”

Potential Use of Mango Waste and Microalgae Spirulina sp. for Bioelectricity Generation

“…Daily current and voltage monitoring was performed using a Prasek Premium PR-85 multimeter and an external resistor of 100 Ω. On the other hand, current density (CD) and power density (PD) values were obtained using external resistors 10 ± 0.2, 40 ± 2.3, 50 ± 2.7, 100 ± 3.2, 300 ± 6.2, 390 ± 7.2, 560 ± 10, 680 ± 12.3, 820 ± 14.5, 1000 ± 20.5 Ω; by the formula CD = I/A and PD = IV/A (Segundo et al, 2022), where I is the current with different external resistors, V is the voltage of open-circuit cells, and A is the area (144 ± 5.2 cm 2 ). Conductivity (conductivity meter CD-4301) and pH (pH meter 110 Series Oakton) changes were also measured, and the resistance values of MFCs were measured using an energy sensor (Vernier ± 30V and ± 1000 mA).…”

Feeding a Membrane-less Microbial Fuel Cell by Mixed Municipal and Industrial Wastewater

“…Various wastewaters from food industry are used in MFCs research, depending on availability (depending on the world region, type of crops or on the type/advancement of the food industry). For research are used the wastewater from production from fruits and vegetables processing, e.g., brewery wastewater [64,65], waste of papaya [56], banana [66], golden berry [67], blueberry [68], onion [69], as well as yeast wastewater [57][58].…”