Disponibilidad potencial de elementos mayoritarios y trazas en los sedimentos del embalse de Sau (Cataluña) ; Potential availability of major and trace elements in the sediments of the Sau reservoir (Catalonia)

Medina M. E., García J. C., Valero F., Gimeno D., Fernández Turiel J. L. Disponibilidad potencial de elementos mayoritarios y trazas en los sedimentos del embalse de Sau (Cataluña). Tecnología del Agua, ISSN 0211-8173, 2005, 256: 66-75. ; [EN] The Sau reservoir (177 hm3), located in the middle part of the Ter river watershed (internal basins of Catalonia), is a key component in the supply of water to Barcelona and its metropolitan area (4.5 million inhabitants). In order to know which elements are more likely to deteriorate the quality of the water due to its greater potential for remobilization in the sediment, geochemical and mineralogical profiles have been carried out on sediment cores sampled in the central part and tail of the reservoir. The environmentally available fraction was determined by ICP-MS in sediment leachates with 10% HNO3 in a 20:1 liquid: solid ratio. The elements with the greatest potential for remobilization are Fe, Al, P, K, Cr, Mn, Cu, Zn, Na, Pb, As and Ni. The area with the greatest potential for remobilization is the tail of the reservoir due to it is more exposed to both variations in the water level, as consequence of the irregular distribution of rainfall over time, and the impact of floods associated with torrential rains. These processes induce variations in the oxidation conditions of the sediment and its re-suspension, respectively, releasing undesirable elements to the water and reducing its quality. ; [ES] El embalse de Sau (177 hm3), situado en la parte media de la cuenca del río Ter (Cuencas internas de Cataluña), es una pieza clave en el suministro de agua a Barcelona y su área metropolitana (4,5 millones de habitantes). A fin de conocer que elementos son más susceptibles de deteriorar la calidad el agua por su mayor potencial de removilización en el sedimento, se han realizado perfiles geoquímicos y mineralógicos sobre testigos de sedimentos muestreados en la parte central y cola del embalse. La fracción ambientalmente disponible se ha determinado por ICP-MS en lixiviados ...