Toxicología ambiental y analítica

Is in vitro Cell Culture Suitable for Study of Environmental-Induced Oxidative Stress?

Distillery sludge is an easy source of plant nutrient but its fertilizer value can vary considerably. In the present study anaerobically digested distillery sludge was applied to agricultural soils and its effect on soil biological and biochemical properties was evaluated. The sludge treatments were comprises of 0, 10, 50, 100 and 150 t ha-1 as single application in an agricultural field and tested for six months. Microbial respiration, microbial biomass carbon, FDA hydrolysis, phosphatase, urease and dehydrogenase activity were evaluated temporally throughout the incubation time for different amount of distillery sludge amendments. These parameters were sensitive enough to show the effect of distillery sludge application on soil microorganisms. The results revealed that sludge application at different rates initially increased the microbial activity, its highest activity was found between 30 and 60 days after application when sludge was applied at the rate of 150 t ha-1 but afterwards the microbial activities decreases gradually. Results show that at high dose soil microbial number increases but the diversity of soil microbial population decreases. Aerobic heterotrophic and symbiotic nitrogen fixing bacteria seems to be more sensitive to sludge addition and shows a marked decrease in population on higher doses. The results also shows that the sludge from distillery wastewater treatment plant may have potential as a beneficial soil amendment up to certain extent for improving biological properties of the soil but at higher doses its contamination can create harm for the beneficial soil inhabitant microbial population and their activities.

Se utilizó irradiación gamma simultánea para preparar resina porosa Epoxy/Pac. Se realizaron caracterizaciones del polímero utilizando infrarrojos por transformada de Fourier (FTIR), análisis termogravimétrico (TGA) y microscopio electrónico de barrido. Se investigó el potencial de sorción del polímero para la eliminación de Cs+ de soluciones líquidas. Se evaluaron las influencias del pH, el tiempo de contacto entre las fases líquida y sólida, la concentración inicial de iones metálicos y la temperatura. Se determinaron isotermas de equilibrio para evaluar la capacidad máxima de sorción del polímero para el ion estudiado. Las mediciones de desorción y durabilidad del polímero confirmaron su uso desde el punto de vista de costo-beneficio. Los datos de sorción de equilibrio se analizaron utilizando modelos de isotermas de Freundlich, Langmuir y Dubinin-Radushkevich (DR). Todos los modelos probados se ajustan razonablemente bien a los datos en términos de coeficientes de regresión. También se realizaron estudios de sorción a diferentes temperaturas para obtener los parámetros termodinámicos del proceso. El valor numérico de ΔG0 disminuye con un aumento de la temperatura, lo que indica que la reacción de sorción de cada ion es más favorable a mayor temperatura. Los valores positivos de ΔH0 corresponden a la naturaleza endotérmica de los procesos de sorción.