Sodium sulfonamides have been extensively used for the treatment of certain infections caused by several types of microorganisms. Although sulfonamides are still widely used in therapeutics, the physicochemical information about their aqueous solutions has not been completed. In this context, the thermodynamic functions of mixing three structurally related sodium sulfonamides were evaluated: Gibbs energy, enthalpy, and entropy. The quantities of mixing were calculated based on the fusion calorimetric values obtained from differential scanning calorimetry measurements and equilibrium solubility values reported in the literature for all the drugs with ethanol + water mixtures. By means of an enthalpy-entropy compensation analysis, non-linear &Delta;H0mix vs. &Delta;G0mix plots with negative slopes from neat ethanol to a 0.60 ethanol mass fraction, and positive slopes from the latter composition to neat water were obtained. From these results, it was concluded that the dissolution process of these drugs in ethanol-rich mixtures was entropy-driven; whereas, in water-rich mixtures the process was enthalpy-driven. Nevertheless, the molecular and ionic events involved in the dissolution of these drugs in this cosolvent system remain unclear.<br>Las sulfonamidas sódicas han sido ampliamente utilizadas en el tratamiento de ciertas infecciones causadas por diferentes microorganismos. Si bien las sulfonamidas siguen siendo ampliamente usadas en la terapéutica actual, la información fisicoquímica de sus soluciones acuosas aún no es completa. En este contexto, estudiamos aquí las funciones termodinámicas de mezcla de tres sulfonamidas sódicas relacionadas estructuralmente y que fueron calculadas a partir de las propiedades calorimétricas de fusión y de los valores de solubilidad en equilibrio en mezclas etanol + agua publicados en la literatura. Mediante análisis de compensación entálpica-entrópica se obtuvieron gráficos no lineales de &Delta;H0mix vs. &Delta;G0mix exhibiendo pendientes negativas desde el etanol puro hasta la mezcla cosolvente de 0,60 en fracción másica de etanol y pendientes positivas desde esta mezcla hasta el agua pura; de acuerdo a este resultado se tiene que el proceso de disolución de estos fármacos en mezclas ricas en etanol es conducido entrópicamente, mientras que en mezclas ricas en agua el proceso es conducido entálpicamente. Sin embargo, los eventos moleculares e iónicos involucrados en el proceso de disolución de este fármaco en este sistema cosolventes aún no son claros.

Sodium sulfadiazine (SD-Na) is a drug extensively used for the treatment of certain infections caused by several kinds of microorganisms. Although SD-Na is widely used nowadays in therapeutics, the physicochemical information about their aqueous solutions is not complete at present. In this context, by using the van’t Hoff and Gibbs equations the thermodynamic functions Gibbs energy, enthalpy, and entropy of solution for SD-Na in ethanol + water cosolvent mixtures, are evaluated from solubility data determined at temperatures from 278.15 to 308.15 K. The drug solubility is greatest in neat water and lowest in neat ethanol at all the temperatures studied. This behavior shows the negative cosolvent effect for this electrolyte drug in this solvent system. By means of enthalpy-entropy compensation analysis, non-linear &Delta;Hsoln0-app vs. &Delta;Gsoln0-app plot with positive slope from neat ethanol up to 0.60 in mass fraction of water and negative from this composition to neat water is obtained; accordingly to this result, it follows that the dissolution process of this drug in ethanol-rich is entropy-driven, whereas, in water-rich mixtures the process is enthalpy-driven. Nevertheless, the molecular and ionic events involved in the dissolution of this drug in this cosolvent system are unclear.<br>La sulfadiazina sódica (SD-Na) es un fármaco ampliamente utilizado en el tratamiento de ciertas infecciones causadas por diferentes microorganismos. Si bien la Na-SD es ampliamente usada en la terapéutica actual, la información fisicoquímica de sus soluciones acuosas aún no es completa. En este contexto, se estudian las funciones termodinámicas aparentes de solución, energía de Gibbs, entalpía y entropía, a partir de valores de solubilidad de este fármaco en mezclas cosolventes etanol + agua en el intervalo de temperatura desde 278,15 hasta 308,15 K. La solubilidad del fármaco es mayor en agua pura y menor en etanol puro a todas las temperaturas estudiadas. Este resultado demuestra el efecto cosolvente negativo del etanol sobre este fármaco del tipo electrolito. Mediante análisis de compensación entálpica- entrópica se obtiene un gráfico no lineal &Delta;Hsoln0-app vs. &Delta;Gsoln0-app exhibiendo pendiente positiva desde el etanol puro hasta la mezcla cosolvente de 0,60 en fracción másica de agua y pendiente negativa desde esta mezcla hasta el agua pura; de acuerdo a este resultado, se tiene que el proceso de disolución de este fármaco en mezclas ricas en etanol es conducido entrópicamente, mientras que en mezclas ricas en agua el proceso es conducido entálpicamente. Sin embargo, los eventos moleculares e iónicos involucrados en el proceso de disolución de este fármaco en este sistema cosolventes no son claros.

The use of fluidized-bed bioreactors in waste and drinking water treatment has several advantages, the most significant of which is the specific removal rate, which is an order of magnitude higher than that of equivalent activated sludge processes. In this paper, the usual concept of nitrification-denitrification in separated units is replaced by a new concept in which the two processes are performed together in a single high-performance fluidized-bed. Based on the former nitrifying reactor, new equipment was designed. This reactor contained a fluidized bed with separated aerobic and anoxic sections for nitrification and denitri fication respectively. This was accomplished by the use of different-diameter sand as carrier material and appropriate reactor shape, recirculation, feed and aeration conditions. The reactor (20 L fluidized-bed volume) was operated for 3 months. It was fed with synthetic waste water (50 L/h) containing 25-40 mg NH₄ ⁺-N/L. Propionic acid and ethanol in a 1:4 ratio were used as the carbon source (2.3 g C/L) for deni trification, fed in at different points of the reactor. Ammonium removal reached 50%, while denitrification was 75%. The total nitrogen removal rate was 0.8-1.2 kg N/m ³.d. A new simple hydrostatic pressure method was used to monitor biofilm thickness in the fluidized bed. During the experiments the oxidation-reduc tion potential (ORP) was tested as a tool to monitor reactor performance; its use for the control of the process was found to be limited.

[ES] Las industrias de bebidas alcohólicas juegan un papel muy importante en la actividad económica de nuestro país y son punteras en el sector agroalimentario, tanto a nivel nacional como de la Comunidad Valenciana. Es evidente el alto consumo que existe en nuestra sociedad con respecto a este tipo de bebidas, estimulado también por numerosas campañas publicitarias, aunque se insiste siempre en que su consumo sea moderado. No obstante, y desde la implantación del carné por puntos, se viene observando una cierta reiteración de la pérdida (total o no) de los mismos tras pasar los conductores por los conocidos controles de alcoholemia. Esto afecta a todo tipo de conductores, entre los cuales obviamente se encuentran los profesionales del sector de la Agronomía. Por citar algún ejemplo concreto, podemos mencionar (a) a los conductores de maquinaria agrícola, quienes pueden estar manejando sus vehículos bajo los efectos de la ingestión de bebidas alcohólicas, bien sea después de comer o tras una pausa en su actividad laboral, o (b) los transportistas de alimentos (frutas, verduras, etc.) que se ven obligados a realizar períodos de descanso a intervalos más o menos regulares, en los cuales pueden consumir bebidas alcohólicas. Como consecuencia entonces de todo ello, vienen proliferando desde hace algún tiempo los intentos -algunos de ellos sin fundamento alguno- de evitar dar positivo en dichos controles de alcoholemia (practicados de forma aleatoria en todo tipo de vías). Y en este sentido, uno de los más serios de los que hay constancia consiste en provocar la oxidación parcial del etanol (CH3-CH2-OH) presente en el aire espirado justo antes de que pase por la boquilla del alcoholímetro. Para conseguir esto, se realizan enjuagues con un colutorio (H2O2, agua oxigenada diluida) disponible en farmacias, de tal forma que se produce una reacción redox: el etanol se oxida a etanal (CH3-CHO) y el peróxido de hidrógeno (H2O2) se reduce a agua (H2O). Por ello nuestra propuesta se basa en estudiar a fondo este curioso procedimiento, realizando previamente un diseño de experimentos seguido de los correspondientes ensayos con las siguientes variables a tener en cuenta: Etanol ingerido, tiempo transcurrido desde la ingesta de etanol hasta el enjuague bucal con el colutorio y hasta el control con el alcoholímetro, concentración de agua oxigenada diluida (colutorio) empleada para cada enjuague bucal, y variación en la medida del alcoholímetro. El objetivo final es determinar la viabilidad de este procedimiento y, en caso afirmativo, alertar así del posible fraude que se podría cometer en los controles de alcoholemia practicados en carreteras. Y en el caso de que fuese negativo, dar a conocer dicho resultado para evitar que conductores, posibles usuarios de este procedimiento, creyendo que estarían a salvo del control de alcoholemia se saltaran la prevención de no beber con el riesgo que ello puede ocasionar. | [EN] Alcohol beverage industries play a very important role in the economic activity of our country, them leading the agri-food sector, especially in the Valencian Community. Everyone knows the high consumption of alcoholic drinks in our society, which is also triggered by a great deal of commercial ads (although they always insist on moderation). Nevertheless, the implementation of the points-based driving license scheme has given rise to frequent total or partial point losses after the corresponding sobriety checks. This affects all drivers, among them those related to Agronomy. Consequently, some fraudulent practices are being developed to avoid positive alcohol tests. Some of them are somewhat ridiculous, but there is a novel procedure that should be remarked, namely: The partial oxidation of expired breathed ethanol after rinsing the mouth with diluted hydrogen peroxide (available in chemist s shops). According to this reaction, ethanol is oxidized to ethanal, whereas hydrogen peroxide is reduced to water. Our proposal is then based on a detailed study of this procedure. The starting point will be an experiment design, followed by testing the different variables involved: amount of ethanol swallowed, time elapsed between the consumption, the mouth rinsing, and the alcohol test, hydrogen peroxide concentration, all of them affecting the ethanol measurement. Our final aim is to determine the feasibility of this method. If yes, a possible fraud in alcohol tests could be avoided. In case of a negative answer, the results obtained could easily discourage the temptation of many drivers to freely drink alcohol, since they could not rely on this procedure for a negative alcohol test. | Nieto Domínguez, A. (2018). Estudio de la viabilidad de enjuagues bucales con agua oxigenada (colutorio) para reducir la medida de etanol en alcoholímetros tras el consumo de bebidas alcohólicas. http://hdl.handle.net/10251/109892

The efficacy of postharvest hot-dip treatment on Redblush grapefruit was investigated by 3-min dips in water at 50°C and 20°C, with and without 1500 ppm imazalil (IMZ) or thiabendazole (TBZ). Fruits were stored for 16 weeks in cold rooms at 8°C and then held at 20°C for 1 week to simulate shelf life. IMZ and TBZ treatment at 20°C considerably reduced the incidence of chilling injury (by about 50-60%) and the percentage (by 20%) of fungal infections. The effectiveness of the two fungicides was found to be considerably increased at 50°C. However, the beneficial effect of hot-dip treatment was noted, whether or not associated with the use of fungicides. The chilling index was threefold lower in fruit dipped in water at 50°C. Similar results were obtained by IMZ treatment and mold decay was decreased by about 50%. IMZ treatment at 50°C proved to be phytotoxic, thus resulting in reddish peel pitting, starting on the fourth week of storage. No further detrimental heat-related effect was detected in the remaining cases. Fruit treated with the two fungicides exhibited no significant differences in respiration rate under cold storage, when compared to control. By contrast, by the end of shelf life, sharply increased values were found in fruit treated with IMZ at 20°C. Endogenous ethylene production and internal quality attributes (juice%, total soluble solid content, juice acidity, and ripening index) did not reveal important differences between treatments. Ethanol concentration in the juice was remarkably lower in fruit treated with the two fungicides, whereas differences due to dip temperature were negligible in most cases.

Enhanced bioremediation combined with in-situ chemical oxidation has the potential to remediate groundwater contaminated with organics. To explore the remediating effects of these two approaches and to evaluate their combined feasibility, traditional gasoline (no ethanol) and ethanol-gasoline (10% ethanol, v/v) were released into experimental sand tanks (TG-tank and EG-tank, respectively) under the same water-flow conditions. Nitrate and sulfate were added to enhance bioremediation and then persulfate was injected to encourage chemical oxidation. Two push–pull tests, using persulfate and bromide respectively, were conducted to compare their behavior. The results showed that nitrate reduction, rather than sulfate reduction, enhanced BTEX (benzene, toluene, ethylbenzene, and xylene) biodegradation, but the presence of ethanol inhibited these processes. The detected concentration of BTEX in the TG-tank was lower than that in the EG-tank, and the first-order decay rate constants of BTEX in the TG-tank and EG-tank under nitrate-adjusted conditions were 0.0058 and 0.0016 d⁻¹, respectively. The first persulfate injection (10 g L⁻¹) resulted in 86 and 94% concentration decreases of BTEX in the TG-tank and EG-tank, respectively, at first-order decay rates of 0.0180 and 0.0181 d⁻¹, respectively. However, the subsequent persulfate injections at 20 and 50 g L⁻¹ had no significant removal effect on BTEX. Persulfate oxidation made pH decrease (but it quickly recovered) and did not significantly inhibit nitrate reduction. This study suggests that enhanced nitrate reduction can be combined with persulfate oxidation for the in-situ remediation of groundwater contaminated by petroleum hydrocarbons.