Biodrying is a complex process that is very useful in the treatment of solid waste, where variables, such as temperature, thermal conductivity and the moisture content of organic matter, oxygen concentration in the pore space of the waste mass, microbial heat generation, microbial biomass, among others, are involved. Given this complexity, the development of mathematical models that help us to understand this bioprocess is fundamental. In the present work, a mathematical model, based on the finite difference method, was developed to predict the temperature profile at nine recording points, in an organic solid waste pile, during the biodrying process. The bioprocess was carried out under natural convection and solar radiation conditions, inside a greenhouse-type structure. A network of 5³ nodes, distributed in the x, y and z directions, on a rectangular prism, was developed. From this network, 27 base nodes were taken and the energy balance was developed for each node, and with this, the equation was obtained, in explicit form, to calculate the temperature. In these base equations, the microbial heat generation was considered, at between 2 and 140 W/m³; the convective coefficient was between 1 and 5 W/m² °C; and the daily records were taken inside the greenhouse for the solar radiation (0 to 450 W/m²), temperature (15 to 50 °C) and RH% (70 to 30). The modeled temperature profiles of the center (C) and the midpoints of the pile were, on average, 91% close to the experimental values, during the period from 0 to 20 days of biodrying; 70% close, during the period from day 21 to 35, the period when the modeled values were lower, due to the turning of the pile; and 94% close to the experimental values from day 36 to 50, when the modeled values were higher, also due to turning. The modeled temperature profiles of the left, right, upper and lower surfaces were, on average 92% close to the experimental profiles over the 0–35 day period, and the modeled and experimental values were practically identical from day 36 to 50 of the biodrying process.

This study presents the development and application of a batch-type photoelectrochemical reactor employing advanced oxidation processes (AOPs) with in situ generated TiO₂ particles for the efficient degradation of azo dyes. The reactor uses titanium sheets as electrodes, facilitating the electrochemical generation of TiO₂, which acts as a photocatalyst under UV light. This study specifically targets azo dyes frequently encountered in industrial wastewater, focusing on Brilliant Blue, Erythrosine, and Tartrazine, which together form the Navy Blue dye composition. The experimental methodology replicates real-world conditions, ensuring the results are representative of practical scenarios. Key findings demonstrate that the in situ production of TiO₂ enables effective heterogeneous photocatalysis, achieving significant dye degradation rates. This research highlights the novelty of combining in situ TiO₂ generation with a batch-type reactor, offering advantages in cost-effectiveness, scalability, and environmental impact. Comparative analysis with existing methods underscores the reactor’s potential for industrial applications, particularly in wastewater treatment. Furthermore, this study outlines the mechanistic insights into dye degradation and provides a foundation for optimizing photocatalytic processes to address environmental challenges.

A fin de mitigar el cambio climático en el mundo, los biocombustibles, particularmente el biodiésel, emergen como una propuesta alternativa sustentable con el medio ambiente. El biodiesel ha presentado un resurgimiento en la investigación debido a la amplia variedad de materias primas que pueden ser utilizadas para su producción en masa con el fin de descarbonizar el transporte y el sector industrial. Una de las materias primas viables es el aceite de piñón debido a que está compuesto por ácidos grasos que pueden transesterificarse y generar un alto rendimiento de biodiesel. Por tal motivo, en la presente investigación se llevó a cabo una simulación del proceso de obtención de biodiesel a partir del aceite de piñón empleando el simulador de procesos Aspen Plus y los modelos termodinámicos UNIQUAC y NTRL para simular los componentes que intervienen en el proceso. Los resultados obtenidos al incluir una estequiometria de mayor complejidad fueron un incremento de la concentración de biodiesel en un 3.48% y reduciendo el consumo de metanol en un 48.8%.