Química Nova (Jan 2007)

Estudo da capacidade de complexação e sua relação com algumas variáveis ambientais em cinco represas do Rio Tietê/Brasil Study of complexation capacity and its relationship with some environmental variables in five reservoirs of the Tietê River system

  • Elisangela C. L. Borges,
  • Antonio Aparecido Mozeto,
  • Eduardo F. Almeida Neves,
  • Waldomiro Borges Neto,
  • José Mauro Bezerra

DOI
https://doi.org/10.1590/S0100-40422007000700002
Journal volume & issue
Vol. 30, no. 7
pp. 1505 – 1511

Abstract

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The copper and cadmium complexation properties in natural sediment suspensions of reservoirs of the Tietê River were studied using the solid membrane copper and cadmium ion-selective electrodes. The complexation and the average conditional stability constants were determined under equilibrium conditions at pH=6.00 ± 0.05 in a medium of 1.0 mol L-1 sodium nitrate, using the Scatchard method. The copper and cadmium electrodes presented Nernstian behavior from 1x10-6 to 1x10-3 mol L-1 of total metal concentration. Scatchard graphs suggest two classes of binding sites for both metals. A multivariate study was done to correlate the reservoirs and the variables: complexation properties, size, total organic carbon, volatile acid sulfide, E II and pH.

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