Contiene: estaciones de muestreo. Analisis de la calidad de agua. Muestreo de campo. Aspectos analiticos. Manejo de datos e informes.

Se presentan los avances en el desarrollo de un nuevo sistema calefactor de piso radiante. El mismo  de basa en  un  piso  de hormigón  que posee en  su  interior agua encapsulada en  botellas de plástico.  El calentamiento  del piso  se realiza a través de circulación  de agua caliente por un  espiral de manguera de PEBD que también  está incrustado  en  el hormigón.  El hormigón  y  el agua encapsulada conforman  una masa térmica de acumulación  por calor sensible.  Este piso  radiante fue diseñado  para que opere totalmente autónomo de la red (gas o electricidad). El calentamiento es a través de colectores solares térmicos, que pueden ser autoconstruidos, y la impulsión del agua recirculante es por una bomba energizada por un  panel fotovoltaico  de muy  baja potencia.  Conformándose un  sistema automatizado simple y económico. Para evaluar la factibilidad de la idea se armó un piso prototipo de menor área 1 m x  lm x  0,15  m.  Usándose una relación  de volúmenes de agua encapsulada y  hormigón  V3/Vh=0,33.Como  característica básica de diseño  se buscó  que en  invierno  la superficie del piso  se mantenga en  el rango higrotérmico de 18°C a 29 °C. Esto pudo lograrse utilizando una relación de 0,5 m2 de superficie  de colección solar/m2 de piso radiante. | Advances in the development of a new radiant floor heating system are presented. It is based on a concrete floor that has water encapsulated in plastic bottles inside. The heating of the floor is done through the circulation of hot water through a PEBD hose spiral that is also embedded in the concrete. The concrete and the encapsulated water make up a thermal mass of accumulation by sensible heat. This radiant floor was designed to operate totally autonomous from the network (gas or electricity), the heating of water is through solar collectors, the impulsion of the recirculating water is for a pump energized by a photovoltaic panel of very few Watts. Conforming a simple and economical automated system. To evaluate the feasibility of the idea, a prototype floor with a smaller area of 1 m x 1 m x 0,15 m was assembled. Using a ratio of volumes of encapsulated water and concrete Va/VH = 0.33. As a basic design feature, it was sought that in winter the floor surface be maintained in the hygrothermal range of 18°C to 29°C. This could be achieved by using a ratio of approximately 0,5 m2 of solar collection surface /m2 of floor heating. | Asociación Argentina de Energía Solar

Trabajo presentado al XII Congreso Ibérico y X Congreso Iberoamericano de Ciencias y Técnicas del Frío (CYTEF 2024), celebrado en Elche, España, 26-28 junio, 2024. | [EN] Deep eutectic solvents (DES) are combinations of hydrogen bonds donors and acceptors, characterized by significantly lower freezing temperatures than their components. NADES (with natural, biologically compatible components) are becoming popular for a wide applications variety, for their wide solvent capacities, non-toxicity, biodegradability, and inexpensive components. Applications include new means for bioactive compounds extraction and enzymatic reactions, polymer solubilizing and a variety of physicochemical processes, including those taking place at low temperature. Four DES (β-alanine and DL-malic or citric acid (plus water) and choline chloride and ethylene glycol or glycerol) were investigated by differential scanning calorimetry (DSC) at low temperature. Pure DES behave completely reversibly, proof of physicochemical stability. Alanine-DES present glass transitions between -40 and -80°C. Meanwhile, choline-DES show no thermal events between 0° and -80°C. Increasing water produces glass transitions in all DES at decreasing temperatures, and devitrifications and freezing events. Choline-DES show no effects up to 20% water. However, alanine-DES show strong water effects, possibly phase separation into different water populations. Calcium alginate-sucrose beads were used as structural model for diffusion systems. Beads were incubated in DES (20 min/20 hours) and their low-temperature properties characterized. Short incubation periods were enough to radically alter their thermal behavior. | [ES] Los disolventes eutécticos profundos (DES) son combinaciones de donantes y aceptores de enlaces de hidrógeno, caracterizados por temperaturas de congelación significativamente más bajas que sus componentes. Los NADES (con componentes naturales y biológicamente compatibles) se están volviendo populares para una amplia variedad de aplicaciones, por su amplia capacidad disolvente, su no toxicidad, su biodegradabilidad y sus componentes económicos. Las aplicaciones incluyen nuevos medios para la extracción de compuestos bioactivos y reacciones enzimáticas, solubilización de polímeros y una variedad de procesos fisicoquímicos, incluidos los que tienen lugar a baja temperatura. Se investigaron cuatro DES (β-alanina y ácido DL-málico o cítrico (más agua) y cloruro de colina y etilenglicol o glicerol) mediante calorimetría diferencial de barrido (DSC) a baja temperatura. Los DES puros se comportan de forma totalmente reversible, prueba de estabilidad fisicoquímica. Los DES a base de alanina presentan transiciones vítreas entre -40 y -80°C. Por su parte, aquellos con colina no muestra eventos térmicos entre 0° y -80°C. La adición de agua produce transiciones vítreas en todos los DES a temperaturas decrecientes y eventos de desvitrificación y congelación. Los DES con colina no muestran efectos hasta un 20% de agua. Sin embargo, los de alanina son muy afectados, con posible separación de fases de agua. Se usaron perlas de alginato de calcio-sacarosa como modelo estructural para sistemas de difusión. Las perlas se incubaron en DES (20 min/20 horas) y se caracterizaron sus propiedades a baja temperatura. Cortos períodos de incubación fueron suficientes para alterar radicalmente su comportamiento térmico. | Peer reviewed

ABSTRACT The main objective of this research is to evaluate the CO2 evolution in a Red Eutrophic Latosol (Eutrudox) fertigated with treated sanitary wastewater under “Prata-Anã” banana cultivation. Disturbed soil samples were collected from 0-20 and 20-40 cm soil profile depths. The experimental design was random blocks arranged in split-plots with four replications. The main plot factors were different treated sanitary wastewater doses applied as 130% and 200% compared with the maximum annual soil application limit (150 kg sodium ha-1) and a control treatment (clean water + mineral fertilization). Soil respiration was evaluated on the 7th, 14th, 21st, and 28th days. The assessment of soil respiration at a depth of 0-20 cm indicates that the use of wastewater increases soil respiration by 19.89 and 28.46%, respectively for treatments TSW1 and TSW2 in relation to the control treatment. At a depth of 20-40 cm, the use of the control treatment promotes an exponential reduction in soil respiration, tending to decrease and stabilize at 58.185 mg C-CO2 kg-1 evolved on the 28th day of evaluation. Treatments with wastewater present respiratory behavior in a quadratic behavior, with minimum respiratory values estimated on the 18th day, respectively 83.4 and 54.0 mg evolved C-CO2 kg-1 for treatments TSW1 and TSW2. | RESUMO O objetivo deste estudo foi avaliar a evolução de CO2 em um LatossoloVermelho Eutrófico (Typic Eutrustox) fertirrigado com água residuária sanitária tratada e cultivado com Banana“Prata-Anã”. Foram coletadas amostras de solo com estrutura deformada nas profundidades de 0-20 e 20-40 cm no perfil do solo cultivado com banana “Prata-Anã”. O delineamento utilizado foi em blocos casualizados em arranjo de parcelas subdividas, com quatro repetições. Os fatores na parcela principal consistiram na aplicação de diferentes doses de água residuária sanitária tratada sendo: 130 % e 200 % em relação ao limite máximo de aplicação anual de 150 kg ha-1 de sódio no solo mais uma testemunha (água limpa + adubação mineral). Avaliou-se aos 7, 14, 21 e 28 dias a respiração microbiana no solo. Na profundidade de 20-40 cm o uso do tratamento controle promove redução exponencial na respiração do solo, tendendo a diminuir e estabilizar em 58,185 mg C-CO2 kg-1 evoluído no 28º dia de avaliação.

Background: Bodies of water in the interior of Isla Mujeres, characterized by having homes around. Objective: Show information on the water quality of the Chica y Grande salt flats of Isla Mujeres, Quintana Roo. Methodology: A study was carried out in each body of water considering different numbers of random points for the measurement of hydrological and microbiological variables in three visits during 2016. The data obtained were analyzed using multivariate exploration techniques (main component analysis) and hypothesis contrast (multivariate variance analysis with permutations). Results: The results indicate that the differences between climatic seasons (north, dry and rain) are more important than the differences between wetlands, with temperature being the variable with more significant changes in the dry season. In terms of water quality, the most relevant indicators were dissolved oxygen and chemical oxygen demand, whose values allow salt flats to be located as bodies of water of low environmental quality. Implications: The importance of having an appropriate monitoring program and management plan for these emblematic ecosystems of the island is highlighted. Conclusion: salt flats are shallow wetlands, with very low concentrations of dissolved oxygen, leading to them being located as ecosystems with low environmental quality. | Antecedentes: Cuerpos de agua en el interior de Isla Mujeres, caracterizados por tener viviendas alrededor. Objetivo/hipótesis: Presentar información sobre la calidad del agua de las salinas Chica y Grande de Isla Mujeres, Quintana Roo. Metodología: Se realizó un estudio en cada cuerpo de agua considerando distintos números de puntos aleatorios para la medición de las variables hidrológicas y microbiológicas en tres visitas durante 2016. Los datos obtenidos se analizaron con técnicas multivariadas de exploración (análisis de componentes principales) y contraste de hipótesis (análisis de varianza multivariado con permutaciones). Resultados: Los resultados indican que las diferencias entre épocas climáticas (nortes, secas y lluvias) son más importantes que las diferencias entre humedales, siendo la temperatura la variable con cambios más significativos en la época seca. En términos de la calidad del agua, los indicadores más relevantes fueron el oxígeno disuelto y la demanda química de oxígeno, cuyos valores permiten ubicar a las salinas como cuerpos de agua de baja calidad ambiental. Implicaciones: Se resalta la importancia de contar con un programa de monitoreo y un plan de manejo adecuado para estos emblemáticos ecosistemas de la isla. Conclusión: las salinas son humedales someros, con muy bajas concentraciones de oxígeno disuelto, lo que lleva a ubicarlos como ecosistemas con una baja calidad ambiental.

Resumen El agua es un recurso cada vez más escaso por lo que tiene una creciente importancia para la sociedad, razón por la cual resulta pertinente y necesaria la determinación de su precio económico. Los objetivos de esta investigación fueron determinar el precio sombra del agua de uso agrícola suministrada por riego de gravedad y de bombeo en la Región Lagunera (Coahuila y Durango), con el fin de calcular las tarifas eficientes, que induzcan un uso óptimo económico del recurso. Se usó un modelo de programación lineal con restricciones de disponibilidad de fuerza de trabajo, tierra y agua. Se analizaron distintos escenarios de disminución de la disponibilidad del agua con el fin de estudiar el comportamiento de su precio sombra ante los cambios en la cantidad disponible de la misma. Los resultados indican que el precio sombra del agua es $1.56 m-3 MN para bombeo y $0.91 m-3 MN para gravedad. Se concluyó que las cuotas que se pagan por el agua de riego en la región son considerablemente menores que el costo de oportunidad o precio sombra del agua. También se concluyó que la asignación actual del agua de uso agrícola genera un patrón de cultivos ineficiente, pues se emplea para producir alfalfa y otros forrajes, los cuales no aparecen en el patrón óptimo de cultivos calculado con el modelo de programación lineal construido para la Región. Se recomienda que las tarifas sean definidas tomando como referencia el precio sombra del agua, el cual se debe ajustar de acuerdo con los cambios periódicos en el nivel de escasez del agua. | Abstract Water is an increasingly scarce resource and therefore has an increasing importance for society, which is why it is pertinent and necessary to determine its economic price. The objectives of this research were to determine the shadow price of agricultural water supplied by gravity irrigation and pumping in the Lagunera Region (Coahuila and Durango), in order to calculate the efficient rates, which induce an optimal economic use of the resource. A linear programming model with restrictions on availability of labor, land and water was used. Different scenarios of decreasing water availability were analyzed in order to study the behavior of its shadow price in the face of changes in the amount available. The results indicate that the water shadow price is $1.56 m-3 MN for pumping and $0.91 m-3 MN for gravity. It was concluded that the fees paid for irrigation water in the region are considerably lower than the opportunity cost or shadow price of water. It was also concluded that the current allocation of water for agricultural use generates an inefficient crop pattern, as it is used to produce alfalfa and other forages, which do not appear in the optimal crop pattern calculated with the linear programming model built for the region. It is recommended that the rates be defined taking as reference the shadow price of water, which should be adjusted according to the periodic changes in the water scarcity level.

Os sais metálicos, especialmente os sais de alumínio, são tradicionalmente os mais empregados no tratamento de água. Contudo, devido aos efeitos deletérios associados ao alumínio residual na água tratada e a dificuldade de dispor o lodo gerado, os polímeros naturais têm sido cada vez mais estudados. Na literatura revisada, os polímeros naturais mais reportados são a Moringa oleifera e a quitosana. Porém, ainda são escassos os trabalhos referentes ao uso de polímeros naturais atuando como coagulantes auxiliares. Portanto, no presente trabalho estudou-se o uso de um novo e potencial coagulante auxiliar, a Guazuma ulmifolia (mutamba), para tratar água sintética empregando a metodologia de superfície de resposta. Além disso, neste trabalho se propôs a realização de uma revisão de literatura especificamente sobre o emprego de polímeros naturais como auxiliares de coagulação a sais metálicos no tratamento de água a fim de identificar as lacunas do conhecimento e oportunidades de pesquisa. Os principais fatores para o processo de coagulação/floculação avaliados foram dose dos coagulantes e pH. Com o processo de modelagem observou-se que o modelo quadrático foi o mais apropriado para descrever o processo de coagulação/floculação, tendo este sido validado. O efeito quadrático do pH, a interação entre a dose de mutamba e o pH e a interação entre a dose de sulfato de alumínio e a dose de mutamba foram significativos (p ≤ 0,05). As condições ótimas previstas pelo modelo foram 5 mg L -1 de sulfato de alumínio, 2,5 mg L -1 de mutamba e pH 9. Ademais, o polímero estudado apresentou características aniônicas (-31,9 mV) atuando, predominantemente, por adsorção e formação de pontes. Palavras-chave: Polímero natural. Mutamba. Tratamento de água. | Metal salts, especially aluminum salts, are traditionally the most employed in water treatment. However, due to the deleterious effects associated with residual aluminum in treated water and the difficulty of disposing of the generated sludge, natural polymers have been increasingly studied. In the reviewed literature, the most commonly reported natural polymers are Moringa oleifera and chitosan. However, there are still few studies on the use of natural polymers acting as coagulants aids. Therefore, the present work optimized the use of a potential new coagulant aid, Guazuma ulmifolia (mutamba), to treat synthetic water using the surface response methodology. In addition, this work aimed to conduct a literature review specifically on the use of natural polymers as coagulation aids to metal salts in water treatment in order to identify knowledge gaps and research opportunities. The main factors for the coagulation-flocculation process evaluated were coagulant dose and pH. The modeling process revealed that the quadratic model was the most appropriate to describe the coagulation-flocculation process, which has been validated. The quadratic effect of pH, the interaction between mutamba dose and pH and the interaction between aluminum sulfate dose and mutamba dose were significant (p ≤ 0.05). The optimal conditions predicted by the model were 5 mg L -1 aluminum sulfate, 2.5 mg L -1 mutamba and pH 9. Moreover, the studied polymer presented anionic characteristics (-31,9 mV) acting by adsorption and bridging. Keywords: Natural polymer. Mutamba. Water treatment.