El presente artículo es una revisión sobre el uso de las enmiendas orgánicas en la inmovilidad del cadmio en suelos agrícolas. El cadmio (Cd), se ha convertido en un problema global desde la industrialización y la implementación de prácticas agrícolas intensivas. En la actualidad, sigue siendo un problema ambiental omnipresente ya que es un metal altamente tóxico que persiste en el suelo por largos periodos debido a su mínima pérdida microbiana y química. Actualmente, existe conciencia pública sobre las implicaciones de los suelos agrícolas contaminados con cadmio y por ello ha aumentado el interés en desarrollar y/o aplicar técnicas rentables, amigables y respetuosas con el ambiente como la inmovilización in situ utilizando enmiendas orgánicas. Se concluye que las enmiendas orgánicas tienen el valor potencial para reducir la captación de Cd por las plantas y mejorar la inmovilización por procesos de adsorción, intercambio iónico, complejación y precipitación.

Polymeric nanocomposites are novel materials of huge interest owing to their favourable cost/performance ratio with low amount of nanofillers, improved thermal resistance, flame retardancy and mechanical properties in relation to their matrices. In this work, composites based on post-industrial waste or primary recycled poly(butylene terephthalate) and 5 wt.% of organic modified montmorillonite clays were melt compounded using a twin-screw extruder. A 2² factorial experimental design was used to study the compounding and processing variables: Organic modified montmorillonite with one or two hydrogenated tallow (initial basal spacing) and screw speed of the extruder. X-ray diffraction and transmission electron microscopy suggest that a partial exfoliation of the organoclay in the recycled poly(butylene terephthalate) matrix was achieved for organic modified montmorillonite with lower initial basal spacing. On the other hand, formulations containing organic modified montmorillonite with higher initial basal spacing showed only intercalated structure. The recycled poly(butylene terephthalate)–organic modified montmorillonite nanocomposites did not drip flaming material during burning tests. Storage of dynamic-mechanical, tensile and flexural moduli of the recycled poly(butylene terephthalate)–organic modified montmorillonite were improved when compared with both virgin and recycled poly(butylene terephthalate)s, mainly for nanocomposites formulated at a lower initial basal spacing organoclay. This could be related to a better diffusion of polymer into organic modified montmorillonite layers compared with the higher initial basal spacing organoclay. The improvements on the physical properties of recycled poly(butylene terephthalate) showed the feasibility to add value to primary recycled engineering thermoplastics with a very small amount of organic modified montmorillonite.

This study aimed to extract and characterize the morphological, physicochemical, thermal, and rheological properties of the starches of native potatoes grown in the department of Puno. Among the varieties evaluated were sweet native potato varieties Imilla Negra (Solanum tuberosum spp. Andígena), Imilla Blanca (Solanum tuberosum spp. Andígena), Peruanita, Albina or Lomo (Solanum chaucha), and Sutamari, and the bitter potatoes Rucki or Luki (Solanum juzepczukii Buk), Locka (Solanum curtilobum), Piñaza (Solanum curtilobum), and Ocucuri (Sola-num curtilobum), acquired from the National Institute of Agrarian Innovation (INIA-Puno). The proximal composition, amylose content, and morphological, thermal, and rheological properties that SEM, DSC, and a rheometer determined, respectively, were evaluated, and the data obtained were statistically analyzed using a completely randomized design and then a comparison of means using Tukey’s LSD test. The results show a significant difference in the proximal composition (p ≤ 0.05) concerning moisture content, proteins, fat, ash, and carbohydrates. Thus, the amylose content was also determined, ranging from 23.60 ± 0.10 to 30.33 ± 0.15%. The size morphology of the granules is 13.09–47.73 µm; for the thermal and rheological properties of the different varieties of potato starch, it is shown that the gelatinization temperature is in a range of 57 to 62 °C and, for enthalpy, between 3 and 5 J/g.

Microencapsulation of virgin coconut oil by spray drying / Microencapsulação de óleo de coco virgem por spray spray

Moringa (Moringa oleifera L.) is a plant highly valued for its content of macronutrients and bioactive elements. The objective of the study was to evaluate the composition of macronutrients and micronutrients of leaf flour, germinated or non-germinated seeds of moringa in the district of La Matanza in the department of Piura, Peru. The proximal analysis revealed that the moringa shoots presented a high protein value on days 2 and 3, with values of 39.25±0.01 g/100 g and 39.26±0.01 g/100 g, respectively. The fat content in the moringa leaf was significantly lower compared to the seed (p≤0.05). The fibre content in the raw seed was higher than the leaf content and the germinated seed (19.95 mg/100 g). The iron and calcium values were higher in the leaves (27.77 mg/100 g) and (1620 mg/100 g), respectively. The results of this study show that both moringa leaves and germinated and non-germinated seeds could significantly provide adequate amounts of protein, fat, fibre, and minerals such as iron and calcium.

El objetivo de la investigación fue estudiar el proceso de adsorción de iones de As (III) con carbón activado de estructura nanoporosa obtenido de lodos orgánicos de aguas residuales. La obtención del carbón activado se realizó mediante una activación química usando ZnCl2 y una activación térmica a 650 °C. Los ensayos de adsorción se realizaron colocando en contacto 16 g/l de carbón activado con soluciones de 0.247, 0.406, 0.564, 0.683 y 0.801 mg/l de As (III) en vasos precipitados de 1 l a un tiempo de 24 horas. Todos los ensayos fueron sometidos a una velocidad de agitación de 720 RPM, a temperatura de 28 °C ± 0.5 y al pH natural de las muestras en laboratorio, el cual fue 3. Los resultados de la caracterización de carbón indicaron que este adsorbente presentó una estructura nanoporosa con presencia de grupos funcionales (hidroxilo y carboxilo). En cuanto a los ensayos de adsorción de As (III), se determinó que el carbón activado logró reducir la concentración del metal hasta 0.004 mg/l, valor que está por debajo de los establecidos por la Organización Mundial de la Salud (OMS) para el consumo de agua. Finalmente se concluye que el carbón activado presentó una eficiencia de 98.4 % de adsorción de iones de As (III) y los datos experimentales mostraron un mayor ajuste al modelo de pseudo-segundo orden y a la isoterma de Freundlich, lo cual indica que el proceso de adsorción de As (III) se realiza en centros enérgicamente heterogéneos mediante una interacción físico-química entre el metal y el adsorbente.