Análisis de los contenidos de tierras raras en el acuífero aluvial del río Guadiamar

Abstract

In this study the contents and normalized patterns of rare earth elements (REE) in the alluvial aquifer of the Guadiamar river are analyzed. The maximum concentrations appear next to the Aznalcóllar mining zone, in an area with low pH values and high concentrations of sulfates and trace metals (Cd, Cu, Co, Ni, Pb and Zn). The high REE contents are relation to the decrease of surface adsorption processes in acid conditions. The normalized patterns with respect to NASC (North American Shale Composite; Taylos and McLennan, 1985) of most contaminated wells show an enrichment in the middle rare earth elements (MREE) over the light (LREE) and heavy ones (HREE), the typical one of acid waters