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Industrialization has brought many environmental problems since its expansion, including heavy metal contamination in water used for agricultural irrigation. This research uses microbial fuel cell technology to generate bioelectricity and remove arsenic, copper, and iron, using contaminated agricultural water as a substrate and Bacillus marisflavi as a biocatalyst. The results obtained for electrical potential and current were 0.798 V and 3.519 mA, respectively, on the sixth day of operation and the pH value was 6.54 with an EC equal to 198.72 mS/cm, with a removal of 99.08, 56.08, and 91.39% of the concentrations of As, Cu, and Fe, respectively, obtained in 72 h. Likewise, total nitrogen concentrations, organic carbon, loss on ignition, dissolved organic carbon, and chemical oxygen demand were reduced by 69.047, 86.922, 85.378, 88.458, and 90.771%, respectively. At the same time, the PDMAX shown was 376.20 ± 15.478 mW/cm2, with a calculated internal resistance of 42.550 ± 12.353 Ω. This technique presents an essential advance in overcoming existing technical barriers because the engineered microbial fuel cells are accessible and scalable. It will generate important value by naturally reducing toxic metals and electrical energy, producing electric currents in a sustainable and affordable way.

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 use of organic waste as fuel for energy generation will reduce the great environmental problems currently caused by the consumption of fossil sources, giving agribusiness companies a profitable way to use their waste. In this research, tomato waste with different percentages of sucrose (0-target, 5, 10, and 20%) was used in microbial fuel cells manufactured on a laboratory scale with zinc and copper electrodes, managing to generate maximum peaks of voltage and a current of 1.08 V and 6.67 mA in the cell with 20% sucrose, in which it was observed that the optimum operating pH was 5.29, while the MFC with 0% (target) sucrose generated 0.91 V and 3.12 A on day 13 with a similar pH, even though all the cells worked in an acidic pH. Likewise, the cell with 20% sucrose had the lowest internal resistance (0.148541 ± 0.012361 KΩ) and the highest power density (224.77 mW/cm2) at a current density of 4.43 mA/cm2, while the MFC with 0% sucrose generated 160.52 mW/cm2 and 4.38 mA/cm2 of power density and current density, respectively, with an internal resistance of 0.34116 ± 0.2914 KΩ. In this sense, the FTIR (Fourier-transform infrared spectroscopy) of all the substrates used showed a high content of phenolic compounds and carboxylate acids. Finally, the MFCs were connected in a series and managed to generate a voltage of 3.43 V, enough to light an LED (green). These results give great hope to companies and society that, in the near future, this technology can be taken to a larger scale.

The improper disposal of plastic waste has become a significant problem, with only a small amount recycled and the rest ending up in landfills or being burned, leading to environmental pollution. In addition, the cost of electric energy has risen by over 100% in the last 20 years, making it unaffordable for remote areas to access this service due to high installation costs, leaving people living far from major cities without electricity. This study proposes an innovative solution to these issues using microbial fuel cell (MFC) technology to simultaneously reduce plastic waste and generate electric energy by utilizing the fungus Aspergillus sp. As a substrate for 45 days. The MFCs reached maximum values of 0.572 ± 0.024 V and 3.608 ± 0.249 mA of voltage and electric current on the thirty-first day, with the substrate operating at a pH of 6.57 ± 0.27 and an electrical conductivity of 257.12 ± 20.9 mS/cm. Furthermore, it was possible to reduce the chemical oxygen demand by 73.77% over the 45 days of MFC operation, while the recorded internal resistance was 27.417 ± 9.810 Ω, indicating a power density of 0.124 ± 0.006 mW/cm2. The initial and final transmittance spectra, obtained using FTIR (Fourier Transform Infrared), showed the characteristic peaks of polyethylene (plastic), with a noticeable reduction in the final spectrum, particularly in the vibration of the C-H compound. After 45 days of fungus operation, the plastic surface used as a sample exhibited perforations and cracks, resulting in a thickness reduction of 313.56 µm. This research represents an initial step in using fungi for plastic reduction and electric energy generation in an alternative and sustainable manner. [ABSTRACT FROM AUTHOR]

To determine the effect of the "Healthy Dish" method to reduce waist circumference in teachers with abdominal obesity in a Peruvian University. Methods: Quasi-experimental, prospective study in 43 teachers, divided into 21 in the control group and 22 in the experimental group, who received a two-session workshop on abdominal obesity and the "Healthy Dish" method. The latter was applied for 2 months, monitored 5 days a week, the waist circumference of both groups was measured at one month and at two months and compared. For the statistical analysis, descriptive and inferential statistics or nonparametric statistics were applied (Mann–Whitney U-test, according to the assumption of normality). Results: The predominant age range was 40 to 49 years, women, married, overweight, with a family history of hypertension, cancer and diabetes mellitus. After the intervention, 40.9% of teachers in the experimental group decreased their waist circumference and 54.5% normalized it, while the control group decreased it by 23.8% and 47.6% normalized it. Only 4.54% of teachers in the experimental group showed no change in their waist circumference, compared to 19.0% in the control group, and 9.52% of teachers in the control group increased their waist circumference. Conclusion: The healthy dish method has a positive effect on decreasing waist circumference in teachers with abdominal obesity. [ABSTRACT FROM AUTHOR]

Heavy metal contamination of water is a widespread problem in Peru and represents a potential threat to the ecosystem. Bacteria are an ecological alternative to treating these effluents. This research aims to determine the influence of temperature and pH on the lead (Pb) bioremoval in surface water using Serratia marcescens under laboratory conditions. The sample was collected from a stream located in Santiago de Chuco City (Peru). Treatments (T) were carried out by combining pH (5 and 7) and temperature (25, 30, and 35 °C). The bacterial inoculum (S. marcescens) was 3 × 108 CFU/mL, which was constant in all treatments. The lead bioremoval evaluation was performed in an airlift bioreactor and the incubation time was 24 h. The total lead concentration was determined using atomic absorption spectrophotometry. The results show that treatment 6 (temperature: 35 °C, pH: 5, and inoculum: 3 × 108 UFC/mL) showed a better result than the other treatments, with a removal value of 63.94%. Furthermore, the total lead concentration decreased from an initial concentration of 0.268 mg Pb/L to a final value of 0.0964 mg Pb/L. These results are still above the allowed water value (15 µg/L) according to Peruvian standards. On the other hand, temperature and pH influenced lead removal from surface water when S. marcescens was used after a short incubation period (24 h). Although an attempt was made to improve lead bioremoval by varying two parameters, temperature and pH, future research is still needed to investigate the effect of different inoculum concentrations, the use of microbial consortia, and a broader range of physicochemical parameters. [ABSTRACT FROM AUTHOR]

Biodiversity in ecosystems is threatened by plastic waste, a significant pollution problem. The research aims to use plastic, Pleorotus ostreatus mycelium, and sugarcane bagasse to develop an eco-friendly biomaterial. The preparation consisted of three phases: (1) Treatment of the underlying layer, (2) inoculation of the fungus (three different concentrations: 15%, M1; 20%, M2; and 25%, M3), and (3) dehydration of the biomaterial. The physical characterization results (density, water absorption, and texture) showed that the average density varies between 127.86 and 131.19 kg/m3; also, the M1 sample had a high percentage of water absorption (23.55%), while M2 obtained lower percentages (11.79%). In the bending test, samples M2 and M3 showed higher structural resistance with stress values of 0.682 and 0.68 MPa, respectively. Based on the results, the produced biomaterials may serve as an alternative to expanded polystyrene (EPS). Due to their moldable characteristics, they can be used in non-structural construction, packaging, and various architectural applications. The research provided promising results; however, additional parameters must be evaluated to be able to commercialize them. [ABSTRACT FROM AUTHOR]

Introduction: Obesity has increased steadily in recent decades, becoming a worldwide pandemic., Objective: To determine the effect of the "Healthy Dish" method to reduce waist circumference in teachers with abdominal obesity in a Peruvian University., Methods: Quasi-experimental, prospective study in 43 teachers, divided into 21 in the control group and 22 in the experimental group, who received a two-session workshop on abdominal obesity and the "Healthy Dish" method. The latter was applied for 2 months, monitored 5 days a week, the waist circumference of both groups was measured at one month and at two months and compared. For the statistical analysis, descriptive and inferential statistics or nonparametric statistics were applied (Mann-Whitney U -test, according to the assumption of normality)., Results: The predominant age range was 40 to 49 years, women, married, overweight, with a family history of hypertension, cancer and diabetes mellitus. After the intervention, 40.9% of teachers in the experimental group decreased their waist circumference and 54.5% normalized it, while the control group decreased it by 23.8% and 47.6% normalized it. Only 4.54% of teachers in the experimental group showed no change in their waist circumference, compared to 19.0% in the control group, and 9.52% of teachers in the control group increased their waist circumference., Conclusion: The healthy dish method has a positive effect on decreasing waist circumference in teachers with abdominal obesity., Competing Interests: All authors have declared no conflicts of interest in this work., (© 2024 Mondéjar Barrios et al.)