Emerging pollutants such as pharmaceuticals have been focusing international attention for a few decades. Ciprofloxacin (CIP) is a common drug that is widely found in hospital and wastewater treatment plants effluents, as well as in rivers. In this work, the feasibility of CIP degradation by ultrasound process at high frequency is discussed and sonolysis, sonolysis with hydrogen peroxide and sono-Fenton are evaluated. The amounts of hydrogen peroxide and ferrous ions (Fe 2+) needed were optimized using response surface methodology. Best results were obtained with the sono-Fenton process resulting in a total pharmaceutical degradation within 15 minutes and a mineralization greater than 60% after one hour. Optimal conditions were tested on a real matrix from a municipal wastewater treatment plant. Even if the degradation of the pollutants by sono-Fenton was hampered, the removal efficiency of both CIP and total organic carbon (TOC) is interesting as an increase in the biodegradability of the wastewater is found. These results show that sono-Fenton oxidation can be a promising pre-treatment process for pharmaceutical-containing wastewaters.
En este trabajo se presenta un estudio de radionucleidos presentes en partículas menores de 1O µm en La Habana, Cuba. El muestreo se realizó utilizo un captador de aire de alto volumen con un flujo constante de 1.13 m3/min y filtros de fibra de cuarzo de 20 x 25 cm. El muestreo comprendió los meses de octubre 2011 - enero 2012. Se recolectaron un total de 14 filtros en los cuales se determinaron valores de concentración radiactiva tales como (208Tl (1.3x 10-4 Bq/m3), 7Be (1.0x10-3 Bq/ m3) ,214Pb (1.5x10-4 Bq/ m3) ,212Pb (3.5 x 10-5 Bq/ m3), 137es (1.3 x10-5Bq/m3). Los radionucleidos fueron medidos en una cámara gamma de bajo fondo con detector de Germanio Hiperpuro (HPGe). El estudio de la roza de los vientos realizado, clasificó un total de 16 fuentes fijas ubicadas en la región del noreste y del este -noreste donde se registraron los mayores eventos de dirección de los vientos en el punto de muestreo. La corrida del modelo HYSPLIT corroboró la incidencia de la dirección predominante de los vientos influyentes en el sitio de muestreo. Las mayores concentraciones de radionucleidos se obtuvieron en los meses donde se registraron los menores eventos de lluvia.
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