A redução de Cr (VI) sobre carbono vitreo reticulado : ensaios preliminares de sua remoção eletrolitica

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

Chromium, despite presenting a high toxic potential, is widely used in several industrial activities, especially in the finishing of metal ware. The concern for environmental issues has led to development of alternative methods for the treatment of the residues, since conventional treatments produce toxic sludge. The study of the reduction of Cr(VI) is aimed at developing a process for its electrolytic removal from aqueous effluents, using an electrolytic cell having a reticulated vitreous carbon cathode. In this study, we have used cyclic voltammetry to determine the potentials for the three reactions that occur during the reduction of Cr(VI). Initially, the reduction to Cr(lIl) is observed at 0.29 V vs. ECS. This is followed by the liberation of hydrogen at - 0.79 V vs. ECS and, finally, the deposition of CR POT.O at -1,15 V vs. ECS. Then the system was studied by the potential pulse technique. The pulse potentials were chosen in such way that favoured the reaction for CR POT.O . The electrodeposited metal was observed by scanning electron microscopy. In the electrolytic removal essays, the process of Cr(VI) reduction showed a lower removal efficiency than was expected

ASSUNTO(S)

eletrodeposição cromo

ACESSO AO ARTIGO

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