Made available in DSpace on 2022-04-29T08:47:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-12-01; In this work was studied the distribution of Cr, Ni, Cu, Cd and Pb in humic fractions with different molecular size. The HS were extracted from waters (AHS), surface sediments (HSSS), interface water sediment (HSIS) and bottom sediment (HSBS) collected in the Anhumas surface water collection reservoir, ...