METALS IN SEDIMENTS OF AN URBAN SHALLOW LAKE IN SANTIAGO (CHILE)

摘要

Fe, Mn, Cu, Zn, Mo and Cr were determined in May 2002 at 25 locations in the sediments of Laguna Caren. Cu, Fe, Mn and Zn showed high concentrations at some stations, on dry weight basis varying from 45000-68000 μg/g for Fe, 850-1600 μg/g for Mn, 100-3900 μg/g for Cu, and 100-170 μg/g for Zn. Cr and Mo showed homogeneous concentrations at all stations, with average levels of 153 and 160 μg/g dry weight, respectively. Co and Ni were found to be below the detection limit of the method. High Cu/Fe and Mo/Fe ratios indicate the accumulation of these metals in sediments. A sequential extraction procedure was applied to samples from five stations, to determine metal distribution. Cu and Mo were found to be mainly associated to the organic matter-sulfides fraction.