Estudo sobre a presença de metais em sedimentos de fundos nos reservatórios hidrelétricos de Balbina - AM e Samuel - RO

Abstract

The Hydroelectric reservoirs on study are located in the largest river basin in the nation. The first one, the HPP-Balbina is located on the Uatumã River which is of acidic waters and dark color, classified as blackwater river. The second one is the HPP-Samuel located in the Jamari River, its waters have acidic characteristics and light color. In the hydroelectric reservoir the water column velocity decreases and causes gradual deposition of sediment washed down by the water, become important sources of information about the historical evolution of the terrestrial and aquatic environments, about the intensity and forms of the impact that these ecosystems were submitted. The aim of this work was to conduct a study about the presence of metallic contaminants in the reservoirs of HPP-Balbina-AM and HPP-Samuel-RO. The characteristics of the waters of the reservoirs were studied in order to register potential difference between both considering the parameters pH, DO, turbidity, temperature and electrical conductivity. The Sediment metals Fe, Cu, Cr, Mn, Zn, Ni, Pb were analyzed by optical emission spectrometry with inductively coupled plasma, being necessary the samples for acid treatment previous extraction of metals. Statistical tests of correlation were used to evaluate the behavior of these elements as its origin in the reservoirs. The results showed that the physical and chemical parameters of water for HPP-Balbina reservoir are within the standards of qualities suggested by the resolution CONAMA 357/05, however the HPP-Samuel reservoir shows that an antropic action is influencing the water quality of this environment. The concentrations of Cr, Cu, Ni and Zn in the reservoir of HPP-Balbina were out of line (TEL) established by NOAA, however high values of Mn, Pb, Zn and Fe were determined in the HPP-Samuel reservoir, so the particle size analysis and statistical tests confirm the results of the concentrations of the elements with a high percentage of silt and clay content and high concentrations of metal elements under study as determined in section SP3 of Samuel reservoir.