Angelica Santis

The preservation of the aquatic environment and water systems has been a fundamental objective that has led great scientists and researchers to seek new alternatives or techniques that allow the decontamination of water sources. The plastic chromium plating industries have been identified as important sources of contamination since their residues are characterized by having considerable amounts of hexavalent chromium Cr (VI), which alters the stability of water resources and can affect effluents on the surface and the subsoil. Given this problem, the need to improve the usual methods and techniques for wastewater treatment with more effective solutions, such as photocatalysis, which presents significant advantages over the inefficiency of traditional methods, is recognized. However, given the limited availability of research in the country that addresses the removal of hexavalent chromium from the wastewater of these industries, this work focuses on optimizing the process by varying conditions of variables such as particle size, catalyst dose, and irradiation time. The optimization of the photocatalysis process was evaluated using the Box-Behnken experimental design. The results show that contaminant removal occurred when the particle size was 0.177 mm. This particle size showed the highest photocatalytic activity, with 100% removal at 45 minutes. These findings represent a significant step towards solving the problem of contamination in this business sector by this pollutant and contribute to preserving our water resources. Doi: 10.28991/ESJ-2024-08-01-02 Full Text: PDF

Today, many organizations are seeking to implement continuous improvement plans not only to achieve greater economic benefits but also to improve the quality of life for their employees. The importance of reducing and preventing workplace accidents, protecting the health and well-being of employees, and preventing work-related illnesses has increased. This article focuses on the development of an Occupational Health and Safety Management System (OHSMS) for an organization in the real estate and property development services sector in Bogotá. The design of the OHSMS is based on the identification of the deficiencies of the current system and the proposal of continuous improvement, according to the ISO 45001: 2018 standard. The design process included three stages of research: 1. initial diagnosis, 2. hazard and risk assessment, and 3. management system performance assessment with appropriate controls and indicators. This article evaluates working conditions in production and in enclosed spaces, such as offices. The integration of these aspects ensures a comprehensive vision of occupational health and safety in real estate and property development companies. The design of the OHSMS is an essential step towards the continuous improvement of working conditions and the well-being of employees. Compliance with the ISO 45001: 2018 standard aims to ensure a safe and healthy working environment for all members of the organization.

This study evaluates the performance of different agricultural by-products to identify the potential effect of independent variables, using as the dependent variable the biogas production. A Box–Behnken experimental design was carried out in a pilot-scale plant of four stirred stainless-steel digesters under mesophilic semi-continuous digestion. The results obtained support the creation of a technical framework to scale up the process and further evaluation of the potential environmental impacts through life cycle assessment (LCA) methodology. A stable behaviour was achieved in 12 of the 13 experiments proposed. The highest value of daily biogas production was 2200.15 mL day⁻¹ with a stabilization time of 14 days, an organic loading rate of 4 g VS feed daily, low C/N ratio and a 1:1 relation of nitrogen providers. The concentrations of CH₄ remained stable after the production stabilization and an average biogas composition of 60.6% CH₄, 40.1% CO₂ and 0.3% O₂ was obtained for the conditions mentioned above. Therefore, the real scale plant was estimated to manage 2.67 tonnes of residual biomass per day, generating 369.69 kWh day⁻¹ of electricity. The LCA analysis confirms that the co-digestion process evaluated is a feasible and environmentally sustainable option for the diversification of the Colombian energy matrix and the development of the agro-industrial sector.