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Several batch scale assays were performed in order to establish a correlation between the microbial removals of n-eieosane, in presence of different concentrations of volatile organic compounds (VOCs) which showed a partial removing. The selected VOCs were toluene aod benzene. Results with benzene showed That The removal of This aromatic compounds was decreased in presence of n-eicosane and the lowest removal was obtained when voc concentration was higher. The removal of hydrocarbon was increased when voc concentration was increased. In the essays with toluene, n-eicosane reached a higher removal when voc concentration was increased, but the aromatic compound showed a decrease in its elimination dynamics. Control assays performed with VOCs at 28 mg/L wilhout hydrocarbon showed higher removal dynamics for benzene than toluene. Also control assays of n-eicosane at two different concentrations but without any VOC showed that its removal dynamic decreased in the absence of the aromatic compounds for both assays. The kinetic adjustment obtained for toluene (Hi11 kinetic model) showed that the removal rate of this compound increased while its concentration at water-phase was higher. Although, when it was used a conceotration of 50 mg/L or higher, the removal rate became almost constant. For benzene, the higher removal rate was reached with 38 mg/L. With higher concentration. The kinetic model showed inhibition, so the adjustment analyses fitted for a Monod kinetic model. n-Eicosaoe showed a better adjustment with the Haldane kinetic model with an initial concentration of 188 mg/L for the highest removal rate.

El presente trabajo tuvo como objetivo principal determinar los posibles impactos sobre el suelo agrícola del Valle de Metztitlán, que se tendrán con la construcción de una segunda refinería en Tula Hidalgo; de acuerdo a un estudio realizado por Garcia et al., en 2005 [1], existe la presencia de HAPs en agua y sedimento del Río y la Laguna del Valle de Metztitlán, lo cual podría estar causando un efecto negativo sobre la población, tanto en la salud como en las cosechas. Para este estudio se utilizó suelo con azolve contaminado con HAPs proveniente de una refinería. En la primera etapa, se hizo una revisión bibliográfica acerca de las enfermedades ocasionadas por estos contaminantes que ha reportado la secretaria de salud del estado de Hidalgo (SSAH) en 2009 [2]. En la segunda etapa, se realizó una caracterización fisicoquímica determinando parámetros (pH, capacidad de campo, porcentaje de humedad, materia orgánica y compuestos inorgánicos) que pudieran influir en la degradación de este contaminante mediante métodos establecidos por Cárdenas en 2003 [3] y por normas ambientales mexicanas. En la tercera etapa, se determinó el HAP más persistente y el más tóxico mediante el método para barrido de compuestos orgánicos establecido en la NOM- 138-SEMARNAT -2003 [4]. Finalmente, se establecieron microcosmos en condiciones anaerobias. De estos microcosmos se tomaron 30 g de suelo donde posteriormente se aclimataron consorcios microbianos para evaluar el posible tiempo de degradación del hidrocarburo encontrado: criseno. Para estas pruebas de biodegradación se utilizó un HAP surrogado que tuviera casi las mismas propiedades fisicoquimicas que el identificado, en este caso fue el 3- y 6- hidroxicriseno, como resultado se obtuvo que este surrogado se degrada en un sistema, de membrana limitante de oxígeno (MLO) en un lapso de tiempo de 40 días.

Hoy en día es una necesidad urgente con carácter social, de salud humana, ambiental e incluso política, asegurar el abastecimiento de agua a las ciudades y poblados de nuestros país. En el caso de Distrito Federal, esta ciudad cuenta con una geografía característica que permite cada año un aporte de agua de lluvia de casi 780 millones de m3 pero solo cerca del 13% de este volumen, se aprovecha. La naturaleza da ejemplos de cómo pueden ser diseñados los sistemas para capturar agua pluvial. Al proceso de estudiar las soluciones que la propia naturaleza ha adoptado se le conoce como biomimetismo y la biomimética es la tecnología que imita a la naturaleza. El objetivo de este trabajo fue copiar principios simples de la naturaleza para diseñar un sistema biomimético de captura y filtración de agua pluvial para casa particulares y unidades habitacionales. Para el diseño del captador biomimético se trabajo con materiales ligeros que no absorben agua sino que la conducen con rapidez a depósitos, debido a que se favorece el fenómeno de cohesión. De los estudios se obtuvo la impermeabilidad de los materiales, su resistencia al flujo y se calcularon los coeficientes de cohesión alcanzados, lo que indica que tanto las moléculas de agua se agrupan entre si y así se evita que se humedezcan los materiales captadores. Estos datos permitieron el diseño final de un primer prototipo.

It is well known that gadolinium chloride (GD) attenuates drug-induced hepatotoxicity by selectively inactivating Kupffer cells. In the present study the effect of GD in reference to cell cycle and postnecrotic liver regeneration induced by thioacetamide (TA) in rats was studied. Two months male rats, intraveously pretreated with a single dose of GD (0.1 mmol/Kg), were intraperitoneally injected with TA (6.6 mmol/Kg). Samples of blood and liver were obtained from rats at 0, 12, 24, 48, 72 and 96 h following TA intoxication. Parameters related to liver damage were determined in blood. In order to evaluate the mechanisms involved in the post-necrotic regenerative state, the levels of cyclin D and cyclin E as well as protein p27 and Proliferating Cell Nuclear Antigen(PCNA) were determined in liver extracts because of their roles in the control of cell cycle check-points. The results showed that GD significantly reduced the extent of necrosis. Noticeable changes were detected in the levels of cyclin D1, cyclin E, p27 and PCNA when compared to those induced by thioacetamide. Thus GD pre-treatment reduced TA-induced liver injury and accelerated the postnecrotic liver regeneration. These results demonstrate that Kupffer cells are involved in TA-induced liver and also in the postnecrotic proliferative liver states., Sección Deptal. de Bioquímica y Biología Molecular (Farmacia), Fac. de Farmacia, TRUE, pub

After 6 months of operation a long-term biofilter was stopped for two weeks and then it was started up again for a second experimental period of almost 1.3 years, with high toluene loads and submitted to several physical and chemical treatments in order to remove excess biomass that could affect the reactor’s performance due to clogging, whose main effect is a high pressure drop. Elimination capacity and removal efficiency were determined after each treatment. The methods applied were: filling with water and draining, backwashing, and air sparging. Different flows and temperatures (20, 30, 45 and 60 °C) were applied, either with distilled water or with different chemicals in aqueous solutions. Treatments with chemicals caused a decrease of the biofilter performance, requiring periods of 1 to 2 weeks to recover previous values. The results indicate that air sparging with pure distilled water as well as with solutions of NaOH (0.01% w/v) and NaOCl (0.01% w/v) were the treatments that removed more biomass, working either at 20, 30 or 45 °C and at relatively low flow rates (below 320 L h−1), but with a high biodegradation inhibition after the treatments. Dry biomass (g VS) content was determined at three different heights of the biofilter in order to carry out each experiment under the same conditions. The same amount of dry biomass when applying a treatment was established so it could be considered that the biofilm conditions were identical. Wet biomass was used as a control of the biofilter’s water content during treatments. Several batch assays were performed to support and quantify the observed inhibitory effects of the different chemicals and temperatures applied.