Heavy metals concentration (Cr, Cu, Ni And Zn) in bottom sediments of the Embu-Mirim River - SP

HEAVY METALS CONCENTRATION (Cr, Cu, Ni and Zn) IN BOTTOM SEDIMENTS OF THE EMBU-MIRIM RIVER - SP

CLAUDIA L. MOURA^1* AND JOEL B. SÍGOLO^2**

¹Programa de Pós-graduação em Geoquímica e Geotectônica, Instituto de Geociências, USP, São Paulo, SP.

²Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, USP, São Paulo, SP.

Presented by ANTONIO C. ROCHA-CAMPOS

Heavy metals distribution in the aquatic ecosystems endowed with human activities is nowadays a serious environmental problem. The number of studies related to heavy metals and bottom sediments have been growing lately, because the bottom sediment is the main reservoir for heavy metals contents.

Ten samples from the Embu-Mirim river were collected and studied in this basin to measure downstream towards the Guarapiranga Reservoir. The purpose is to study the Cr, Cu, Ni and Zn contents in the bottom sediments sampled by means of two subsamples, one at the top and the other in the base of the core sediments. The influence of the physicochemical properties (pH and Eh), the organic matter data and granulometric data were correlated to the heavy metals found in this environment. The research shows the probable contamination by those metals in the sediment of the Guarapiranga Reservoir.

The results obtained so far suggest a possible tendency of the values of Cr, Ni and Zn to depend on the properties of the organic matter, and that the Cu amounts are being governed by the pH values, as a function of the sources emission of those metals. The granularity is directly related to the concentration of the metals, because the sampling stations with larger amounts of metals are clayey, while the smallest amounts were found in the stations of sandy size.

With the collected data, an environmental approach becomes relevant in the area, seeking to improve the quality of the bottom sediment, mainly for Cr and Ni that present considerable decline in the quality of the water of the Guarapiranga Reservoir. — (December 14, 2001).

Publication Dates

• Publication in this collection
  09 Oct 2002
• Date of issue
  Sept 2002