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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Chemical behavior of Cu, Zn, Cd, and Pb in a eutrophic reservoir: speciation and complexation capacity

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Author(s):
Tonietto, Alessandra Emanuele [1] ; Lombardi, Ana Teresa ; Choueri, Rodrigo Brasil [2] ; Vieira, Armando Augusto Henriques [3]
Total Authors: 4
Affiliation:
[1] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil
[2] Univ Fed Sao Paulo, Dept Sea Sci, BR-11030400 Santos, SP - Brazil
[3] Univ Santa Cecilia, Postgrad Program Ecol, BR-11045907 Santos, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Environmental Science and Pollution Research; v. 22, n. 20, p. 15920-15930, OCT 2015.
Web of Science Citations: 5
Abstract

This research aimed at evaluating cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) speciation in water samples as well as determining water quality parameters (alkalinity, chlorophyll a, chloride, conductivity, dissolved organic carbon, dissolved oxygen, inorganic carbon, nitrate, pH, total suspended solids, and water temperature) in a eutrophic reservoir. This was performed through calculation of free metal ions using the chemical equilibrium software MINEQL+ 4.61, determination of labile, dissolved, and total metal concentrations via differential pulse anodic stripping voltammetry, and determination of complexed metal by the difference between the total concentration of dissolved and labile metal. Additionally, ligand complexation capacities (CC), such as the strength of the association of metalsligands (logK'(ML)) and ligand concentrations (CL) were calculated via Ruzic's linearization method. Water samples were taken in winter and summer, and the results showed that for total and dissolved metals, Zn > Cu > Pb > Cd concentration. In general, higher concentrations of Cu and Zn remained complexed with the dissolved fraction, while Pb was mostly complexed with particulate materials. Chemical equilibrium modeling (MINEQL+) showed that Zn2+ and Cd2+ dominated the labile species, while Cu and Pb were complexed with carbonates. Zinc was a unique metal for which a direct relation between dissolved species with labile and complexed forms was obtained. The CC for ligands indicated a higher CL for Cu, followed by Pb, Zn, and Cd in decreasing amounts. Nevertheless, the strength of the association of all metals and their respective ligands was similar. Factor analysis with principal component analysis as the extraction procedure confirmed seasonal effects on water quality parameters and metal speciation. Total, dissolved, and complexed Cu and total, dissolved, complexed, and labile Pb species were all higher in winter, whereas in summer, Zn was mostly present in the complexed form. A high degree of deterioration of the reservoir was confirmed by the results of this study. (AU)

FAPESP's process: 05/51263-5 - Fate of dissolved organic matter released by Cyanobacteria in an eutrophic reservoir (Tietê River): studies of processes
Grantee:Armando Augusto Henriques Vieira
Support Opportunities: Research Projects - Thematic Grants