Determinación de sodio en agua por fotometría de llama | Melián, Cecilia. Centro Universitario de Estudios Medioambientales. Cátedra de Química Biológica. Facultad de Ciencias Médicas de la UNR; Argentina

A banana é uma cultura de grande relevância econômica e socioambiental, com perdas significativas ocorrendo ao longo da cadeia de produção, especialmente na fase de pós-colheita. O uso de ozônio surge como uma alternativa promissora e segura aos tratamentos químicos convencionais para minimizar essas perdas. Este estudo teve como objetivo avaliar os modelos cinéticos da reação do ozônio em água em diferentes temperaturas e determinar a eficácia da imersão em água ozonizada no controle de Colletotrichum musae em bananas, além de analisar os impactos na qualidade do produto durante o armazenamento. Desta forma, foram testados cinco tratamentos na variedade de banana ‘Nanicão’: controle (sem imersão), imersão em água sem ozônio (dois e três ciclos), e imersão em água ozonizada (dois e três ciclos). Cada ciclo durou 15 minutos. Após o tratamento, os frutos foram armazenados por 9 dias a 25 °C e 75% UR. Os resultados mostraram que a maior concentração de ozônio e o tempo de meia-vida mais prolongado (117,6 minutos) foram alcançados a 15 °C. No entanto, na presença de bananas, a meia- vida foi drasticamente reduzida para apenas 0,9 minutos. Não houve efeito significativo do tratamento com água ozonizada no controle da antracnose ou na qualidade das frutas durante o armazenamento. Concluiu-se que, embora a meia- vida do ozônio seja maior a 15 °C, a matéria orgânica presente na banana reduz substancialmente esse tempo, e a imersão em água ozonizada não foi eficaz no controle de antracnose Palavras-chave: musa spp; ozônio; modelos cinéticos; saturação; decaimento; pós- colheita. | Banana is a crop of great economic and socio-environmental relevance, with significant losses occurring throughout the production chain, especially during the postharvest phase. The use of ozone arises as a promising and safe alternative to conventional chemical treatments to minimize these losses. This study aimed to evaluate the kinetic models of ozone reaction in water at different temperatures and to determine the effectiveness of immersion in ozonated water in controlling Colletotrichum musae in bananas, as well as to analyze the impacts on product quality during storage. For this, five treatments were tested on the 'Nanicão' banana variety: control (no immersion), immersion in water without ozone (two and three cycles), and immersion in ozonated water (two and three cycles). Each cycle lasted 15 minutes. After the treatment, the fruits were stored for 9 days at 25°C and 75% RH. The results showed that the highest ozone concentration and the longest half-life (117.6 minutes) were achieved at 15°C. However, in the presence of bananas, the half-life was drastically reduced to just 0.9 minutes. There was no significant effect of ozonated water treatment on anthracnose control or fruit quality during storage. It was concluded that, although the ozone half-life is longer at 15°C, the organic matter present in bananas substantially reduces this time, and immersion in ozonated water was not effective in controlling anthracnose. Keywords: musa spp; ozone; kinetic models; saturation; decay; post-harvest. | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Water when subjected to magnetic fields undergoes physicochemical changes and when used in agriculture has shown interesting effects on plant development and seed germination. The objective was to evaluate the effects of magnetized water under germination and dormancy of lettuce seeds (Lactuca sativa) in view of the scarcity of available data on the subject. The experiment was conducted at the Federal University of Uberlandia campus Monte Carmelo, under laboratory conditions. Genotypes UFU-125#2#2#1, UFU-206#1#6#1 and the commercial cultivar Grand Rapids were used in a completely randomized experimental design DIC, being a factorial scheme 2x3. Comprising deionized water, magnetized water and temperatures of twenty-thirty degrees Celsius with four replications. The treatments and repetitions were conducted in gerbox with germitest paper, and each gerbox received twenty five seeds, totaling two hundred seeds of each genotype. Daily evaluations were performed for seven consecutive days according to the Rules for Seed Analysis – RAS for data collection. At the end, the results were processed using the SISVAR software and subjected to analysis of variance, the means were compared by Tukey test at the level of 5 % probability. The magnetized water did not provide significant gains in relation to deionized water for the germination of lettuce seeds, and the treatments with deionized and magnetized water received the same averages when subjected to the test. For the treatments submitted to temperature of 30 °C there was no seed twinning in both cases. | Trabalho de Conclusão de Curso (Graduação) | A água quando submetida a campos magnéticos sofre alterações físico-químicas e quando utilizadas na agricultura tem demonstrado efeitos interessantes no desenvolvimento de plantas e na germinação de sementes. O objetivo foi avaliar os efeitos da água magnetizada sob a germinação e dormência de sementes de alface (Lactuca sativa) tendo em vista a escassez de dados disponíveis sobre o assunto. O experimento foi conduzido na Universidade Federal de Uberlândia campus Monte Carmelo, em condições de laboratório. Foram utilizados genótipos UFU-125#2#2#1, UFU-206#1#6#1 e a cultivar comercial Grand Rapids, em um delineamento experimental totalmente casualizado DIC, sendo um esquema fatorial 2x3. Compreendendo água deionizada, água magnetizada e temperaturas de vinte e trinta graus célsius com quatro repetições. Os tratamentos e repetições foram conduzidos em gerbox com papel germitest, sendo que cada gerbox recebeu vinte cinco sementes, totalizando duzentas sementes de cada genótipo. Foram realizadas avaliações diárias durante sete dias consecutivos de acordo com as Regras para Análise de Sementes – RAS para a coleta dos dados. Ao final, os resultados foram processados utilizando o software SISVAR e submetidos à análise de variância, as médias foram comparadas pelo teste de Tukey ao nível de 5 % de probabilidade. A água magnetizada não proporcionou ganhos significativos em relação a água deionizada para a germinação das sementes de alface, tendo os tratamentos com água deionizada e magnetizada recebido as mesmas médias quando submetidas ao teste. Para os tratamentos submetidos a temperatura de 30 °C não houve geminação de sementes em ambos os casos.

Phytoremediation of aquatic plants is a technology for the bioremediation of contaminated waters that is presented as an economical and effective alternative in the extraction of contaminants. Of the great diversity of Panamanian flora, Lemna Minor stands out for its capacity to retain heavy metals and as biomass for the generation of biogas. Due to this, a bio-treatment of wastewater is proposed for the mining industry, implementing phytoremediation to absorb the mercury (Hg) residues generated in its process and anaerobic co-digestion after the extraction of mercury for energy cogeneration. The bibliographic review on the mercury absorption capacity in Lemna Minor and the data collected in the laboratory allowed defining parameters, obtaining as results the reproduction rate of the plant PA=7.78 g/m^2/h , absorption rate of mercury per unit mass of Lemna C_Hglemna=0.28μg/(g h) and the yield for minimum methane production under heavy metal toxicity in Lemna, PBM=132 L/kg.S Extreme conditions of mercury concentrations found in mining regions of Asia of 103 μg/L were considered in which Posada & Arroyave Maya, 2006, verified that under these conditions the reproduction rate of Lemna Minor is not affected. Obtaining an area necessary for the treatment of these conditions of 15.21 hectáreas y un subproducto para la cogeneración de la planta mediante la implementación de codigestión anaeróbica de 156 228 L/h biogás. | La fitorremediación de plantas acuáticas es una tecnología para la biorremediación de aguas contaminadas que se presenta como una alternativa económica y eficaz en la extracción de contaminantes. De la gran diversidad de la flora panameña, se resalta la Lemna Minor por su capacidad de retención de metales pesados y como biomasa para la generación de biogás. Debido a esto, se propone un bio-tratamiento de aguas residuales para la industria minera, implementando la fitorremediación para absorber los residuos de mercurio (Hg) generados en su proceso y la codigestión anaeróbica posterior a la extracción de mercurio para la cogeneración de energía. La revisión bibliográfica sobre la capacidad de absorción de mercurio en la Lemna Minor y los datos recolectados en el laboratorio permitió definir parámetros, obteniendo como resultados la tasa de reproducción de la planta PA=7.78 g/m^2/h , tasa de absorción de mercurio por unidad de masa de Lemna C_Hglemna=0.28μg/(g h) y el rendimiento para la producción de metano mínimo bajo toxicidad de metales pesados en Lemna, PBM=132 L/kg.Se consideraron condiciones extremas de concentraciones de mercurio encontradas en regiones mineras de Asia de 103 μg/L en el que Posada & Arroyave Maya, 2006, comprobaron que bajo estas condiciones la tasa de reproducción de Lemna Minor no se ve afectada. Obteniendo un área necesaria para el tratamiento de estas condiciones de 15.21 hectáreas y un subproducto para la cogeneración de la planta mediante la implementación de codigestión anaeróbica de 156 228 L/h biogás.

El objetivo de la investigación fue cuantificar el aporte que el agua hizo al valor de la producción agrícola bajo la modalidad de riego en México durante el periodo 1980-2017. Para tal fin, con base en la metodología econométrica, se estimó un modelo logarítmico hiperbólico o recíproco logarítmico, pertinente para una función producción cuando se considera solo un insumo mientras los demás permanecen constantes. La variable explicada fue el logaritmo natural del valor de la producción agrícola bajo riego al nivel nacional en pesos constantes de 2013, la variable explicativa fue la inversa del agua suministrada para riego en hectómetros cúbicos; ambas variables fueron I(0). Se comprobó que las regiones hidrológico-administrativas I, II, III, IV, VI, VII y VIII -estados del norte y del bajío del país- concentran el 89.4% del total de la superficie de riego nacional, regiones hidrológico-administrativas, que fueron altamente beneficiadas con las inversiones federales en los distritos y las unidades de riego. Durante el periodo analizado se detectaron dos cambios estructurales: 1) de 1980-1987; y 2) de 2009-2017. Se concluyó que el aporte del agua al valor de la producción bajo riego registró tendencia positiva, en 1980 fue de $0.39 m-3 y para 2017 de $1.92 m-3, para el periodo 1980-1987 de $0.39 m-3, para 1988-2008 de $1.11 m-3, para 2009-2017 de $1.74 m-3. Finalmente, el aporte promedio, del periodo considerado, del agua al valor de la producción bajo riego en México fue de $1.11 m-3. | Abstract The objective of the research was to quantify the contribution that water made to the value of agricultural production under the irrigation modality in Mexico during the period 1980-2017. For this purpose, based on the econometric methodology, a hyperbolic logarithmic or logarithmic reciprocal model was estimated, relevant for a production function when only one input is considered while the others remain constant. The variable explained was the natural logarithm of the value of irrigated agricultural production at the national level in constant pesos of 2013, the explanatory variable was the inverse of the water supplied for irrigation in cubic hectometers; both variables were I(0). It was found that the hydrological-administrative regions I, II, III, IV, VI, VII, and VIII -northern and Bajío states of the country- concentrate 89.4% of the total national irrigated area, hydrological-administrative regions that were highly benefited with federal investments in the irrigation districts and units. During the period analyzed, two structural changes were detected: 1) from 1980 to 1987; and 2) from 2009 to 2017. It was concluded that the contribution of water to the value of irrigated production registered a positive trend, it was $0.39 m-3 in 1980, $1.92 m-3 in 2017, $0.39 m-3 for the period 1980-1987, $1.11 m-3 for 1988-2008, $1.74 m-3 for 2009-2017. Finally, during the period considered, the average contribution of water to the value of irrigated production in Mexico was $1.11 m-3.

Se evaluó el efecto del ozono en fase acuosa para la desinfección de tomates (Lycopersicon esculentum Mill.) cultivar FA-180. Los tomates maduros fueron inoculados con Escherichia coli ATCC 25922 y posteriormente lavados con agua ozonizada bajo dos sistemas de agitación durante 15 y 30 min a concentraciones de ozono disuelto de 0,5 y 1,0 mg/L y se evaluó la concentración del microorganismo en los tomates tratados y no tratados. Se comprobó que el ozono en fase acuosa ejerce un marcado efecto en la desinfección de tomates contaminados, resultando el sistema de lavado con zaranda el más adecuado. Se recomienda una concentración de ozono disuelto de 1 mg/ L y un tiempo de tratamiento de 15 min para lograr un grado de desinfección satisfactorio en tomates maduros. | The aim of this study was to evaluate the effect of the ozoned water for the disinfection of tomatoes (Lycopersicon esculentum Mill.) FA-180. The ripened tomatoes were inoculated with Escherichia coli ATCC 25922 and washed with ozoned water under two systems of agitation during 15 and 30 min in concentrations of dissolved ozone of 0.5 and 1.0 mg/L, and it was evaluated the concentration of the microorganism in the treated and non treated tomatoes. It was demonstrated that ozone in aqueous phase has a marked effect in the disinfection of polluted tomatoes, and the washing system with a lab shaker was the more appropriated. A concentration of dissolved ozone of 1 mg/L and a time of treatment of 15 min are recommended to achieve a satisfactory disinfection in ripened tomatoes.

Universidad Nacional Agraria La Molina. Facultad de Ciencias. Departamento Académico de Ingeniería Ambiental, Física y Meteorología | La presente investigación evaluó la influencia de la calidad del agua superficial del río Títire (afluente) en las características hidroquímicas del río Coralaque (cuerpo receptor), pertenecientes a la subcuenca del río Coralaque, Moquegua, Perú. Primero, se evaluó la variación temporal y espacial de los ríos mencionados, mediante el uso del índice de calidad del agua (ICARHS) y el índice metálico (IM); donde se determinó que el río Títire presenta elevadas concentraciones aluminio, arsénico, boro, manganeso, conductividad eléctrica y nivel de pH, entre otros; obteniendo una calidad de agua inferior (calidad mala) respecto al río Coralaque (calidad regular). Luego, se desarrolló la evaluación hidroquímica y la fuente de generación, donde se demostró que los procesos que controlan las características hidroquímicas de los ríos Títire y Coralaque son la evaporación y cristalización y meteorización de las rocas (interacción agua-roca), así como el dominio de la lixiviación; por lo que se deduce que influyen tanto procesos naturales como antropogénicos. Asimismo, se determinó que el agua del río Títire no es aptas para el riego, mientras que el agua del río Coralaque solo es apta para plantas muy resistentes a la salinidad en general. Para simular la dispersión de los parámetros se empleó el modelamiento con CORMIX, donde se obtuvo que aguas debajo de la zona de mezcla en la mayoría de los casos las concentraciones son superiores a los valores establecidos del ECA-Agua. Asimismo, se determinó que las aguas del río Títire sobre el río Coralaque, representa un riesgo ecotoxicológico en la fauna acuática de la zona. Finalmente, se desarrolló el análisis de componentes principales (ACP) que permitió corroborar los resultados obtenidos. Se concluye que la composición hidroquímica del río Títire si influye en la calidad del agua del río Coralaque. | The present investigation evaluated the influence of the quality of the surface water of the Títire River (tributary) on the hydrochemical characteristics of the Coralaque River (receiving body), belonging to the sub-basin of the Coralaque River, Moquegua, Peru. First, the temporal and spatial variation of the mentioned rivers was evaluated, using the water quality index (ICARHS) and the metallic index (IM); where it was determined that the Títire River has high concentrations of aluminum, arsenic, boron, manganese, electrical conductivity and pH level, among others; obtaining a lower quality of water (poor quality) compared to the Coralaque River (fair quality). Then, the hydrochemical evaluation and the generation source were developed, where it was demonstrated that the processes that control the hydrochemical characteristics of the Títire and Coralaque rivers are the evaporation and crystallization and weathering of the rocks (water-rock interaction), as well as the leaching mastery; Therefore, it is deduced that both natural and anthropogenic processes influence. Likewise, it was determined that the water from the Títire River is not suitable for irrigation, while the water from the Coralaque River is only suitable for plants that are very resistant to salinity in general. To simulate the dispersion of the parameters, modeling with CORMIX was used, where it was obtained that downstream of the mixing zone in most cases the concentrations are higher than the established values of the ECA-Water. Likewise, it was determined that the waters of the Títire River on the Coralaque River represent an ecotoxicological risk to the aquatic fauna of the area. Finally, the principal components analysis (PCA) was developed to corroborate the results obtained. It is concluded that the hydrochemical composition of the Títire River does influence the water quality of the Coralaque River.

ABSTRACT: Wave energy converters (WEC) may be a promising option for extracting the energy available in the sea and ocean in a clean way. The oscillating water column (OWC) is one of the most well-known and applicable WEC systems. In this work, computational fluid dynamics (CFD) was employed to simulate an OWC at the shore numerically adapted to the Pacific Ocean conditions. For this purpose, ANSYS-Fluent software was used, and Reynolds-Averaged Navier Stokes (RANS) equations were solved through the program in two dimensions. The Volume of Fluid (VOF) scheme and the laminar viscosity model were used for the description of the water-air interface and the fluid modeling, respectively. The regular waves were generated using Stokes second-order nonlinear theory by directly fitting as input the boundary condition as an open channel wave and the volume fraction parameters through implicit formulation. The variation of the free water surface elevation and the pressure drop inside the resonance chamber were investigated; the results showed that for the studied OWC, an efficiency of 0.672 was obtained. | RESUMEN: Los convertidores de energía de las olas (WEC) pueden ser una opción prometedora para extraer la energía disponible en el mar y los océanos de manera limpia. La columna de agua oscilante (OWC) es uno de los sistemas WEC más conocidos y aplicables. En este documento, se empleó la dinámica de fluidos computacional (CFD) para simular numéricamente una OWC en la orilla adaptada a las condiciones del Océano Pacífico. Para este propósito, se utilizó el programa ANSYS-Fluent y las ecuaciones de Navier Stokes promediadas de Reynolds (RANS) fueron resueltas a través del programa en dos dimensiones. El esquema de Volumen de Fluido (VOF) y el modelo de viscosidad laminar fueron usados para la descripción de la interfaz entre el agua y el aire, y el modelamiento del fluido, respectivamente. Las olas regulares se generaron utilizando la teoría no lineal de segundo orden de Stokes ajustando directamente como entrada la condición de contorno como una ola de canal abierto y los parámetros de fracción de volumen a través de formulación implícita. La variación de la elevación de la superficie libre de agua y la caída de presión dentro de la cámara de resonancia fueron investigados, los resultados mostraron que para la OWC estudiada, se obtuvo una eficiencia de 0.672. | Convocatoria para el fortalecimiento de CTeI en Instituciones de Educación Superior (IES) Públicas 2020 | COL0008058

La creciente demanda de alternativas a los hidrogeles sintéticos y la inconveniente proliferación de la Eichhornia crassipes que causa afectaciones al medio ambiente, parecen ser dos problemáticas que se pueden solventar entre sí. Este estudio pretendía evaluar la viabilidad de esta planta invasora como fuente de celulosa para la fabricación de hidrogeles físicos de uso tópico. Para ello, se obtuvieron cuatro prototipos mediante variaciones de la metodología Organosolv, los cuales fueron caracterizados farmacotécnicamente y reológicamente. Los ensayos revelaron que cada prototipo obtenido se trataba de un hidrogel, con un contenido de agua superior al 92%, determinado por pérdida por secado, y un rendimiento del 31.1% ± 4.9%. La esparcibilidad señaló el prototipo B como semifluido, mientras que las pruebas reológicas determinaron que entre los prototipos no hay diferencias significativas y son pseudoplásticos garantizando el uso como hidrogeles tópicos. Además, todos los hidrogeles demostraron una baja citotoxicidad. Un análisis IR sugirió diferencias estructurales en cada uno de los hidrogeles, confirmando a su vez la prevalencia de celulosa. Se llevó a cabo un análisis de varianza (p < 0.05) para determinar cambios significativos. En conjunto, estos hallazgos sugieren que la Eichhornia crassipes es una fuente viable para la fabricación de hidrogeles. | Pregrado | Químico Farmacéutico | The increasing demand for alternatives to synthetic hydrogels and the issue of Eichhornia crassipes' proliferation, which causes environmental damage, seem to be two problems that can be addressed by each other. This study aimed to evaluate the feasibility of utilizing this invasive plant as a source of cellulose for the fabrication of topical-use physical hydrogels. Four prototypes were synthesized via variations of the Organosolv methodology and subsequently subjected to pharmaceutical characterization. The experimental assays demonstrated that each prototype constituted a hydrogel, characterized by a water content exceeding 92%, as determined through drying loss, with a yield of 31.1% ± 4.9%. Evaluation of spreadability indicated the suitability of prototype B, while rheological assessments determined that there were no significant differences among the prototypes and they were all pseudoplastic, enserió their use as topical hydrogels. Furthermore, all hydrogels exhibited low cytotoxicity. Infrared spectroscopy revealed distinctive structural variances among the hydrogel formulations, confirming the predominance of cellulose. Statistical analysis, conducted via analysis of variance (p < 0.05), underscored significant differences. Collectively, these findings display the potential of Eichhornia crassipes as a viable cellulose source for hydrogel production.