This study aimed to produce activated carbon from desilicated rice husks using various carbonization and activation methods, including a tube furnace, muffle furnace, and artisanal pyrolysis. The resulting activated carbons were characterized for their adsorptive capacity through the determination of iodine number and methylene blue adsorption; these are key indicators of specific surface area and adsorbent quality. Advanced characterization techniques were employed, such as scanning electron microscopy (SEM), which revealed a highly porous and irregular surface structure, and energy dispersive X-ray spectroscopy (EDS), confirming the effective removal of impurities and optimization of the elemental composition. Atomic force microscopy (AFM) demonstrated favorable surface roughness for adsorption processes. Among the samples, CaDH162-CADH53 exhibited the highest performance, with an iodine number of 1094.8 mg/g and a yield of 93.5%, signifying a high adsorption capacity. The activation treatments with phosphoric acid and calcium carbonate significantly improved the porous structure, further enhancing the material’s adsorptive properties. In conclusion, the activated carbons produced in this study demonstrated optimal physicochemical properties for water purification and contaminant treatment applications. These findings highlight the potential of using agricultural waste, such as rice husk, as a sustainable and scalable alternative for industrial-scale activated carbon production.

This study focused on the comprehensive characterization of the adsorbent obtained from rice husk, which was selected for its high adsorption capacity in iodine solution (IS) and methylene blue solution (MBS). This was achieved with adsorbents prepared by a combined treatment involving calcium carbonate prior to carbonization and activation with phosphoric acid. Characterization was performed using advanced techniques, such as scanning electron microscopy (SEM), atomic force microscopy (AFM), laser light diffraction and energy-dispersive X-ray spectroscopy (EDS), which allowed for the evaluation of the adsorbent’s microstructure and composition. The results revealed a complex structure of the adsorbents with interconnected pores, which facilitates efficient adsorption in IS and MBS and the standard indicators to evaluate adsorption capacity. The novelty of this study lies in the application of advanced characterization techniques to optimize the adsorbent properties and understand how preparation conditions affect the adsorbent’s microstructure. The characterized adsorbent materials in this study presented great potential for applications in water treatment and industrial processes, offering an economical and environmentally sustainable solution. Promoting the use of rice husks in the production of adsorbents contributes to the circular economy, reducing production costs and environmental pollution. The results suggested that these materials are effective in the removal of pollutants, which make them relevant for practical applications in water and soil bioremediation.

Mahogany (Swietenia macrophylla), is a widely used timber tree species valued for its hardness, strength, beauty and quality. Intensive explotation and inadequate use of this species have resulted in the loss of genetic variability, making impossible the implementation of breeding programs of mahogany in Ecuador. In vitro culture is a promising technique that would help reducing this problem by producing plants with high genetic strength. The objective of this research was to establish a method to facilitate in vitro propagation of mahogany from nodal segments. In order to prevent contamination, nodal segments were treated with Ca(ClO)2 solution for 20 min. Healthy explants were transferred to MS/2 culture medium with different concentrations of benzylaminopurine (BAP) and indolebutyric acid (IBA) for further in vitro proliferation, obtaining 70% of shoots on medium supplemented with 2 mg L-1 of BAP and 1 mg L-1 IBA. Bud treatment with different concentrations of ANA for in vitro rooting was not efficient, although the greatest survival rate (65%) was obtained on culture mediumcontaining 2 mg L-1 BAP and 1 mg L-1 NAA. La caoba (Swietenia macrophylla) es una especie forestal maderable de múltiples usos, apreciada por su dureza, resistencia, belleza y calidad. La explotación intensiva y un inadecuado sistema de aprovechamiento de la especie han ocasionado la disminución de la variabilidad genética, haciendo imposible la aplicación de programas de mejoramiento genético de caoba en el Ecuador. El cultivo in vitro es una técnica que ayudaría a disminuir este problema mediante la producción de plantas con alta robustez genética. El objetivo de esta investigación fue establecer un método que facilite la propagación in vitro de caoba a partir de segmentos nodales, empleados en la fase de establecimiento con diferentes concentraciones de Ca(ClO)2 y tiempos de exposición. La contaminación por microorganismos fue controlada con 15 g de Ca(ClO)2 durante 20 min, alcanzando el 95% de sobrevivencia. Los explantes sanos fueron transferidos a un medio de cultivo MS/2 con distintos niveles de bencilaminopurina (BAP) y ácido indolbutírico (AIB) para su multiplicación in vitro, obteniéndose 70% de brotes con 2 mg L-1 de BAP en combinación con 1 mg L-1 de AIB. Los mejores brotes de la fase de multiplicación se colocaron en medio de cultivo MS/2 con diferentes concentraciones de ANA para facilitar su enraizamiento, ninguno de los tratamientos ensayados permitió generar raíces a los 21 días de su evaluación, aunque el mayor porcentaje de sobrevivencia (65%) se obtuvo al combinar 2 mg L-1 BAP + 1 mg L-1 ANA.

From cocoa almonds, fermented and dried (or un fermented) by-products and final products are obtained through industrial processes. This research aimed to improve the quality characteristics of national cocoa almonds (Theobroma Cacao L.) for chocolate processing, through the biochemical modification of cocoa tiledon in the post-box stage, thus improving reactions occurring within the cotiledon in almonds with the addition of yeasts (Saccharomyces cerevisiae) in the post-box stage, undergoing fermentation with yeast in two times 3 and 4 days of fermentation, which helped to modify biochemical within the cotiledon of cocoa almonds, improving their physical, chemical characteristics and organoleptic attributes. The results obtained from the experimental design with the addition of yeast (Saccharomyces cerevisiae), have shown the improvement of physical, chemical characteristics and their organoleptic attributes compared to the witness. Because favorable results were obtained in T4 treatments (0.125% yeast x with lylasses) and T6 (0.250 % of yeasts with mingle) in terms of physical and chemical analyses such as: moisture, cutting test and acidity; and in turn higher quality score on its organoleptic attributes.