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This research proposes an alternative for companies and farmers through the production of electricity using microbial fuel cells (MFCs) using waste from export products. Nine MFCs were manufactured with zinc and copper electrodes; and as substrates, pineapple, potato and tomato pulp wastes were used in the anode chamber, and residual sludge in the cathode chamber. It was observed that the MFCs with pineapple substrate generated higher values of the electrical parameters, resulting in voltage and current values of 0.3484 ± 0.003 V and 27.88 ± 0.23 mA, respectively. It was also observed that the maximum power density was 0.967 ± 0.059 W/cm² at a current density of 0.04777 A/cm² for the same substrate. Acid pH values were observed in the three samples, while the conductivity reached its maximum value on day 23 (69.47 ± 0.91 mS/cm) which declined until the last day of monitoring; the turbidity values increased abruptly after day 22 until the last day where a value of 200.3 ± 2.52 UNT was observed for the pineapple substrate. The scanning electron microscopy for the pineapple substrate MFC electrodes shows the formation of a porous biofilm on the zinc and copper electrodes. These results show that a new form of electricity production has been achieved by generating high voltage and current values, using low-cost materials. [ABSTRACT FROM AUTHOR]

Abstract This research has developed a piece of sanitizing locker-model equipment for textiles exposed to avian coronavirus, which has been put under the influence of UV light, UV + zinc oxide nanoparticles (phytosynthesized ZnONP), and water + UV, and, in turn, under the influence of the exposure time (60, 120, 180 s). The results linked to the phytosynthesis of ZnONP indicate a novel method of fabricating nanostructured material, nanoparticles with spherical morphology and an average size of 30 nm. The assays were made based on the viral viability of avian coronavirus according to the mortality of SPF embryonated eggs and a Real-Time PCR for viral load estimation. This was a model to evaluate the sanitizing effects against coronaviruses since they share a very similar structure and chemistry with SAR-CoV-2. The influence of the type of textile treatment evidenced the potential effect of the sanitizing UV light, which achieved 100% of embryo viability. The response of the ZnONP + UV nebulization showed a notorious influence of photoactivation according to the exposure time, and the 60-s treatment achieved a decrease of 88.9% in viral viability, compared to 77.8% and 55.6% corresponding to the 120 and 180-s treatments, respectively. Regarding the decrease in viral load between the types of treatments, UV 180 s reduced 98.42% and UV 60 s + ZnONP reduced 99.46%, respectively. The results show the combinatorial effect of UV light and zinc nanoparticles in decreasing the viral viability of avian coronavirus, as a model of other important coronaviruses in public health such as SARS-CoV-2.

The potential for the application of metal-containing nanomaterials at the nanoscale promotes the opportunity to search for new methods for their elaboration, with special attention to those sustainable methods. In response to these challenges, we have investigated a new method for green synthesis of cuprous oxide nanoparticles (Cu2O NPs) using Myrciaria dubia juice as an organic reductant and, comparing it with chemical synthesis, evaluating in both cases the influence of the volume of the organic (juice) and chemical (ascorbic acid) reductants, for which a large number of techniques such as spectrophotometry, EDX spectrometry, TEM, SEM, DLS, FTIR spectroscopy have been used. Likewise, the nanomaterial with better morphological characteristics, stability, and size homogeneity has been applied in the functionalization of textiles by means of in situ and post-synthesis impregnation methods. The success of the synthesis process has been demonstrated by the antimicrobial activity (bacteria and fungi) of textiles impregnated with Cu2O NPs.

This research aimed to use kiwi waste as fuel to generate bioelectricity through microbial fuel cells. It was possible to generate an electrical current and voltage peaks of 3.807 ± 0.102 mA and 0.993 ± 0.061 V on day 11, showing an electrical conductivity of 189.82 ± 3.029 mS/cm and an optimum operating pH of 5.966 ± 0.121. The internal resistance of the cells was calculated using Ohm’s Law, resulting in a value of 14.957 ± 0.394 Ω, while the maximum power density was 212.68 ± 26.84 mW/m2 at a current density of 4.506 A/cm2. Through the analysis of the FTIR spectra carried out on the substrate, a decrease in the characteristic organic peaks was observed due to their decomposition during the electricity-generation process. In addition, it was possible to molecularly identify the bacteria Comamonas testosteroni, Sphingobacterium sp., and Stenotropho-monas maltophila adhered to the anodized biofilm. Finally, the capacity of this residue to generate bioelectricity was demonstrated by lighting an LED bulb with a voltage of 2.85 V.

The excessive use of fossil sources for the generation of electrical energy and the increase in different organic wastes have caused great damage to the environment; these problems have promoted new ways of generating electricity in an eco-friendly manner using organic waste. In this sense, this research uses single-chamber microbial fuel cells with zinc and copper as electrodes and pineapple waste as fuel (substrate). Current and voltage peaks of 4.95667 ± 0.54775 mA and 0.99 ± 0.03 V were generated on days 16 and 20, respectively, with the substrate operating at an acid pH of 5.21 ± 0.18 and an electrical conductivity of 145.16 ± 9.86 mS/cm at two degrees Brix. Thus, it was also found that the internal resistance of the cells was 865.845 ± 4.726 Ω, and a maximum power density of 513.99 ± 6.54 mW/m2 was generated at a current density of 6.123 A/m2, and the final FTIR spectrum showed a clear decrease in the initial transmittance peaks. Finally, from the biofilm formed on the anodic electrode, it was possible to molecularly identify the yeast Wickerhamomyces anomalus with 99.82% accuracy. In this way, this research provides a method that companies exporting and importing this fruit may use to generate electrical energy from its waste.

The accelerated increase in energy consumption by human activity has generated an increase in the search for new energies that do not pollute the environment, due to this, microbial fuel cells are shown as a promising technology. The objective of this research was to observe the influence on the generation of bioelectricity of sucrose, with different percentages (0%, 5%, 10% and 20%), in papaya waste using microbial fuel cells (MFCs). It was possible to generate voltage and current peaks of 0.955 V and 5.079 mA for the cell with 20% sucrose, which operated at an optimal pH of 4.98 on day fifteen. In the same way, the internal resistance values of all the cells were influenced by the increase in sucrose, showing that the cell without sucrose was 0.1952 ± 0.00214 KΩ and with 20% it was 0.044306 ± 0.0014 KΩ. The maximum power density was 583.09 mW/cm2 at a current density of 407.13 A/cm2 and with a peak voltage of 910.94 mV, while phenolic compounds are the ones with the greatest presence in the FTIR (Fourier transform infrared spectroscopy) absorbance spectrum. We were able to molecularly identify the species Achromobacter xylosoxidans (99.32%), Acinetobacter bereziniae (99.93%) and Stenotrophomonas maltophilia (100%) present in the anode electrode of the MFCs. This research gives a novel use for sucrose to increase the energy values in a microbial fuel cell, improving the existing ones and generating a novel way of generating electricity that is friendly to the environment.

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.

Tomato is an important crop due to its nutritional contributions and organoleptic properties, which make it an appetizing vegetable around the world. In its sowing, the use of seed is the most accessible propagation mechanism for farmers. However, the induction to germination and emergence is often limited in the absence of stimulants that promote the development and growth of the seedling, added to the interference of infectious agents that notoriously reduce the vitality and viability of the seed. Given this, it was proposed as a research objective to determine the effect of zinc oxide nanoparticles (ZnO NPs) mediated by a green route on the germinative characteristics of Lycopersicon esculentum Mill. 1768 “tomato”. The experimental phase consisted of the synthesis of ZnO NPs and its subsequent characterization. After its synthesis, its inoculation was conducted during the germination of seeds of L. esculentum, considering six sample groups for the treatment with zinc nanoparticles (T1: Control; T2: 21.31 ppm; T3: 33.58 ppm; T4: 49.15 ppm; T5: 63.59 and T6: 99.076 ppm). The results indicate that concentrations close to 100 ppm of ZnO NPs are ideal in the treatment of L. esculentum seeds, due to the promotion of enzymatic and metabolic activity to achieve cell elongation; likewise, the biosynthesized nanoparticles showed no phytotoxicity, due to the fact that, in all the treatments, there were processes of germination and emergence. This was linked to the generation of a Zn0-phenolate complex through a chelating effect, which generates compatibility with the seed and, compared to classic inorganic synthesis, usually shows phytotoxicity. In this sense, green synthesis is presented as a great alternative in this type of application.

The study evaluates five types of commercial textiles with different cotton and polyester contents widely used in the garment industry. These textile samples have been subjected to treatment by the exhaustion method using zinc oxide nanoparticles (NP ZnO) (textile functionalization) with the aim of improving their efficiency in blocking UV radiation. The ZnO nanoparticles have been obtained by two methods: The green or also called biosynthesis (using the extract of Coriandrum sativum as an organic reducing agent), and the chemical method (using NaOH as an inorganic reducing agent). The results related to the green method show having achieved a defined geometric configuration with an average size of 97.77 nm (SD: 9.53). On the contrary, the nanostructures obtained by the chemical method show pentagonal configurations with average sizes of 113 nm (SD: 6.72). The textiles functionalized with NP ZnO obtained by biosynthesis showed a better efficiency in blocking ultraviolet radiation (UV).