Comparison of two synthesis methods on the preparation of Fe, N-Co-doped TiO2 materials for degradation of pharmaceutical compounds under visible light

"In this work, we report the synthesis, characterization and photocatalytic evaluation of visible light active iron-nitrogen co-doped titanium dioxide (Fe3+-TiO2?xNx) nanostructured catalyst. Fe3+-TiO2?xNx was synthesized using two different chemical approaches: sol-gel (SG) and microwave (MW) methods. The materials were fully characterized using several techniques (SEM, UV–Vis diffuse reflectance DRS, X-ray diffraction XRD, and X-ray photoelectron spectroscopy XPS). The photocatalytic activity of the nanostructured materials synthesized by both methods was evaluated for the degradation of amoxicillin (AMX), streptomycin (STR) and diclofenac (DCF) in aqueous solution. Higher degradation efficiencies were encountered for the materials synthesized by the SG method, for instance, degradation efficiencies values of 58.61% (SG) and 46.12% (MW) were observed for AMX after 240 min of photocatalytic treatment under visible light at pH 3.5. With STR the following results removal efficiencies were obtained: 49.67% (SG) and 39.90% (MW) at pH 8. It was observed the increasing of degradation efficiencies values at longer treatment periods, i.e., after 300 min of photocatalytic treatment under visible light, AMX had a degradation efficiency value of 69.15% (MW) at pH 3.5, DCF 72.3% (MW) at pH 5, and STR 58.49% (MW) at pH 8.

Características morfométricas y calidad de gel en sábila ("Aloe barbadensis" M.) aplicando algaenzimas y composta

The study was conducted in 2011-2012 and aimed to evaluate the effect of different sources and doses of fertilizers on leaf growth and quality on aloe vera gel, the latter as a product of high demand in the market. A random split plot block design with three replications was used. The main plots were algae extract (algaenzims) doses (0, 7 and 14 L ha-1) and subplots compost doses (0.5 and 10 t ha-1). The measured variables were: plant height, width, length and thickness of leaf; while in juice and gel, pH, °Brix, total solids, settleable solids in methanol, proteins, carbohydrates, gel content and macro (P, K, Ca, Mg and Na) were measured. Plant height and leaf length were significantly higher (p= 0.05) by applying 14 L ha-1 of algaenzims. Gel content, sugar and settleable solids in methanol were significantly higher, 273 days after the first application of the biofertilizer (DDPAB) (December), 273-393 DDPAB (December-April) and 273 DDPAB (December), respectively. The content of P and Mg were significantly reduced, 273 DDPAB (December) by applying 10 t ha-1 of compost, then the content of these elements is recovered. The carbohydrate and protein content increased significantly at 273 DDPAB (December), which is critical to identify the cutoff date of aloe leaf.El estudio se llevó a cabo en 2011 y 2012 y tuvo como objetivo evaluar el efecto de diferentes fuentes y dosis de fertilizantes en el crecimiento de la hoja de sábila y la calidad del gel, este último como el producto de mayor demanda en el mercado. Se usó un diseño de bloques al azar en parcelas divididas con tres repeticiones. Las parcelas grandes fueron las dosis de algaenzimas (0, 7 y 14 L ha-1) y las parcelas chicas las dosis de composta (0.5 y 10 t ha-1). Las variables que se midieron fueron: la altura de planta, ancho, largo y grosor de hoja; en tanto que en el jugo y gel, se midió el pH, °Brix, sólidos totales, sólidos precipitables en metanol, proteínas, carbohidratos, contenido de gel y macroelementos (P, K, Ca, Mg y Na). La altura de planta y largo de la hoja, fueron significativamente mayores (p= 0.05) al aplicar 14 L ha-1 de algaenzimas. Los contenidos de gel, azúcares y sólidos precipitables en metanol, fueron significativamente mayores, 273 días después de la primera aplicación de los biofertilizantes (DDPAB) (diciembre), 273-393 DDPAB (diciembre-abril) y 273 DDPAB (diciembre), respectivamente. El contenido de P y Mg se redujeron significativamente, 273 DDPAB (diciembre) al aplicar 10 t ha-1 de composta, después se recupera el contenido de estos elementos. El contenido de carbohidratos y proteínas se incrementaron significativamente a los 273 DDPAB (diciembre), lo cual es determinante para identificar la fecha de corte de hoja de sábila

Uso de biofertilizantes en la producción de sábila Aloe vera (L.) L. N. Burm y calidad de gel

The demand of organic products derived of aloe leaf is increasing. The objective of this study was to evaluate different sources and dosages of biofertilizers on growing of aloe leaf and gel quality. Random block design was used, using humic acids: (0, 54 and 108 L ha-1), and (0, 5 and 10 t ha-1) of vermicompost. The aloe leaf thickness was higher (P≤ 0.05) when it was applied 10 t ha-1 of compost. Percentage of total solids, solids precipitated in methanol, and carbohydrates content were higher in December of 2011, which increase the gel quality. Phosphorus (P) was the only nutrient with a higher concentration of humic acids corresponding to 108 L ha-1. Use of bio-fertilizers like vermicompost and humic acids are an option for improving the production of leaf and aloe gel quality, if considering the date of aloe leaf harvest.La demanda de productos orgánicos derivados de la hoja de sábila es cada vez mayor. El objetivo de este estudio fue evaluar el efecto de distintas fuentes y dosis de biofertilizantes en el crecimiento de la hoja y calidad del gel de sábila. Se usó un diseño de bloques al azar, con ácidos húmicos: 0, 54 y 108 l ha-1, y 0, 5 y 10 t ha-1 de lombricomposta. El grosor de hoja fue mayor cuando se aplicó 10 t ha-1 de lombricomposta; la concentración de sólidos totales, sólidos precipitables en metanol y carbohidratos se incrementaron significativamente en diciembre de 2011, lo cual eleva la calidad del gel. El fósforo (P) mostró una mayor concentración cuando se aplicaron 108 l ha-1 de ácidos húmicos. El uso de biofertilizantes como la lombricomposta y los ácidos húmicos son una opción para mejorar la producción de sábila, si se toma en cuenta la fecha de siega