Author(s):
Cidália M. S. Botelho 
; Rui A. R. Boaventura
Date: 2009
Persistent ID: http://hdl.handle.net/10216/68026
Origin: Repositório Aberto da Universidade do Porto
Subject(s): Ciências Naturais; Ciências do ambiente
Description
The extractable contents of Zn, Pb, Cu, Cr, Mn, Ni, Fe and Al were evaluated in sediments
from the Lis River (Portugal) using the three-step sequential extraction procedure
described by Community Bureau of Reference (BCR, now the Standards, Measurement
and Testing Programme) of the European Union. The distribution of trace metals among
the exchangeable, water and acid soluble, reducible, oxidizable and residual fractions
was determined. The highest metal concentrations were observed in samples collected
at the most polluted river sites (animal husbandry, domestic, industrial and agricultural
wastes). Pb, Cu, Cr, Ni, Fe and Al were found mainly associated with the residual and organic
fractions. High concentrations of Zn and Mn were found in the exchangeable/acid
soluble fraction.
