Conference Agenda

The presence of synthetic dyes in aquatic systems constitutes a significant environmental problem, especially in the current context of water scarcity. These compounds generate adverse impacts on both aquatic ecosystems, by inhibiting processes such as photosynthesis, and on human health, due to their persistence and potential toxicity. This study evaluated a composite obtained through green synthesis, based on biochar and iron nanoparticles, for the removal of the dye gentian violet, with the aim of contributing to the mitigation of its environmental impact in aquatic environments.

The composite was synthesized using an extract of Peumus boldus and characterized by infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and potentiometric titration. The removal of gentian violet was evaluated as a function of pH, composite dosage (2–32 mg), and contact time, in order to determine the optimal operating conditions and elucidate the dye removal mechanism. The composite synthesis yielded 42.6%. Under optimal conditions (pH 10, 4 mg dose, and 24 h contact time), a removal efficiency of 95.2% and an adsorption capacity of 9.5 mg/g were achieved. However, considering operational criteria, a contact time of 4 h was established, resulting in a removal efficiency of 88%. Kinetic analysis indicated that the experimental data fit the pseudo-second-order model well (R² = 0.9995), suggesting that the removal process is primarily governed by a chemical adsorption mechanism.

The textile industry requires high-purity salt as a critical raw material for dyeing. However, in many developing countries, including Honduras, locally produced marine salt does not consistently meet industrial purity specifications, resulting in dependency on imports and higher production costs. This study presents the design and simulation of a marine salt purification process aimed at textile-grade applications, using Aspen Plus as the primary modeling tool.

The proposed process integrates brine pretreatment, chemical coagulation, filtration, heat exchange, vacuum crystallization, centrifugation, and convective drying. An electrolyte-based thermodynamic model was implemented to accurately represent salt dissociation, impurity precipitation and phase behavior. Equilibrium constants, solubility data, and reaction sets were defined to simulate impurity removal, particularly magnesium and calcium salts. Laboratory-scale data were used to validate feed composition and preliminary operating conditions.

Process performance was evaluated through mass and energy balances, product composition analysis, and sensitivity studies on key operating variables such as reagent dosage, water addition, vapor flow rates, and drying conditions. The simulation results indicate that the process achieves a final sodium chloride purity of approximately 98.3% by mass, suitable for industrial textile use, with an overall process yield of 93.3%. Sensitivity analysis identified optimal operating regions that maximize purity while minimizing reagent and energy consumption.

This study evaluated the industrial potential of quartz sandstones from Quelluacocha, Cajamarca, through physicochemical and mineralogical characterization. Sieve analysis in accordance with ASTM C136, petrographic microscopy, and calcination tests were conducted to determine the granulometric, textural, and chemical properties of the material. The results indicate a predominant sandy fraction (66.40%) with a fineness modulus of 2.39, corresponding to medium sand. Mineralogical analysis revealed a high quartz content (72–76%) with mainly sub-angular grains, while chemical tests showed an average SiO₂ content of 64.54%, exceeding the minimum requirements established for siliceous aggregates. These characteristics confer adequate hardness, mechanical strength, and chemical stability. Therefore, the evaluated sandstones are considered suitable for use as fine aggregates in the regional construction industry.

This work presents an electrochemical and kinetic assessment of the corrosion behavior of a 1.25Cr–0.5Mo steel in 0.5 M HCl under controlled temperature and hydrodynamic conditions, representative of acidic cleaning environments. Potentiodynamic polarization (PDP), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) were applied at 25, 45, and 65 °C, and at 25 °C under agitation (350 and 700 rpm), using triplicate measurements. The steel exhibited active dissolution without passivation in all conditions. Corrosion rates increased markedly with temperature, reaching ~13–15 mm·year⁻¹ at 65 °C, compared with ~1.15–1.23 mm·year⁻¹ at 25 °C (static). Agitation at 25 °C accelerated corrosion from ~1.2 mm·year⁻¹ (static) to ~3.5–3.7 mm·year⁻¹ (350 rpm) and ~5.6–5.8 mm·year⁻¹ (700 rpm), indicating a strong hydrodynamic enhancement of mass transport and surface renewal. EIS spectra showed a single depressed capacitive loop, consistent with charge-transfer control; Rct decreased and Cdl increased with temperature and agitation. Corrosion rates obtained by PDP, LPR, EIS, and EFM agreed well. Arrhenius analysis yielded apparent activation energies of ~50–52 kJ·mol⁻¹ across techniques (R² ≈ 0.99–0.999), supporting a consistent kinetic regime dominated by interfacial charge transfer. These results provide quantitative evidence of the critical impact of temperature and flow conditions on metal loss in hydrochloric acid environments for Cr–Mo boiler steels.

El acero ASTM A335 P91 es un material ferrítico–martensítico de alta aleación ampliamente utilizado en componentes que operan a altas temperaturas, donde la degradación por corrosión en medios ácidos puede limitar su desempeño en servicio. Los ensayos se realizaron en soluciones de HCl 0.5 M y H₂SO₄ 0.5 M a 25, 45 y 65 °C, bajo condiciones aireadas. Las técnicas de polarización potenciodinámica, resistencia a la polarización lineal (LPR), espectroscopía de impedancia electroquímica (EIS) y modulación de frecuencia electroquímica (EFM) fueron empleadas para caracterizar la cinética de corrosión y los procesos electroquímicos en la interfase metal–solución. Los resultados muestran que la velocidad de corrosión se incrementa significativamente con el aumento de la temperatura en ambos medios ácidos, siguiendo una relación de tipo Arrhenius. El análisis de impedancia reveló que el incremento de la temperatura produce una disminución de la resistencia a la transferencia de carga y un aumento de la capacitancia de la doble capa eléctrica, lo que indica una mayor actividad electroquímica en la superficie del acero. La técnica EFM proporcionó parámetros de corrosión confiables, confirmados por factores de causalidad próximos a los valores teóricos, y mostró una buena concordancia con los resultados obtenidos mediante las técnicas de Tafel, LPR y EIS. Estos resultados aportan información electroquímica cuantitativa y una mejor comprensión del efecto de la temperatura sobre la corrosión del acero ASTM A335 P91, contribuyendo a la evaluación del desempeño de materiales metálicos en condiciones de servicio ácido.

Abstract– Biotechnology applied to nematode management in coffee plantations offers sustainable solutions to the damage caused by Meloidogyne and Pratylenchus. Through the use of mycorrhizae, endophytic fungi, biofumigants, and resistant germplasm, the use of chemical inputs is reduced, soil health is improved, and crop productivity is increased. These strategies, supported by institutions such as FAO and IHCAFE, promote regenerative and efficient agricultural practices. Furthermore, the scientific and institutional approach fosters innovation and sustainability in coffee farming, strengthening the resilience of production systems and improving the quality of life of smallholder producers.

Resumen - La biotecnología aplicada al manejo de nematodos en cafetales ofrece soluciones sostenibles frente a los daños causados por Meloidogyne y Pratylenchus. Mediante el uso de micorrizas, hongos endófitos, biofumigantes y germoplasma resistente, se reduce el uso de químicos, se mejora la salud del suelo y se incrementa la productividad del cultivo. Estas estrategias, respaldadas por instituciones como la FAO e IHCAFE, promueven prácticas agrícolas regenerativas y eficientes. Además, el enfoque científico e institucional impulsa la innovación y sostenibilidad en la caficultura, fortaleciendo la resiliencia de los sistemas productivos y mejorando la calidad de vida de los pequeños productores.