Influence of chloride-mediated oxidation on the electrochemical degradation of the direct black 22 dye using boron-doped diamond and β-PbO2 anodes

Author(s)

Douglas A. C. Coledam ^[1] ; José M. Aquino ^[2] ; Romeu C. Rocha-Filho ^[3] ; Nerilso Bocchi ^[4] ; Sonia R. Biaggio ^[5]

Affiliation

^[1] Universidade Federal de São Carlos. Departamento de Química - Brasil

^[2] Universidade Federal de São Carlos. Departamento de Química - Brasil

^[3] Universidade Federal de São Carlos. Departamento de Química - Brasil

^[4] Universidade Federal de São Carlos. Departamento de Química - Brasil

^[5] Universidade Federal de São Carlos. Departamento de Química - Brasil

• Document type: Journal article
• Source: Química Nova; v. 37, n. 8, p. 1312-1317, 2014-00-00.

Abstract

The Direct Black 22 dye was electrooxidized at 30 mA cm-2 in a flow cell using a BDD or β-PbO2 anode, varying pH (3, 7, 11), temperature (10, 25, 45 °C), and [NaCl] (0 or 1.5 g L-1). In the presence of NaCl, decolorization rates were similar for all conditions investigated, but much higher than predicted through a theoretical model assuming mass-transport control; similar behavior was observed for COD removal (at pH 7, 25 °C), independently of the anode. With no NaCl, COD removals were also higher than predicted with a theoretical model, which suggests the existence of distinct dye degradation pathways. (AU)

• FAPESP's process: 12/13587-7 - Use of metallic oxides deposited on planar and tridimensional substrates for the electrochemical and photochemical degradation of organic pollutants
• Grantee: José Mario de Aquino
• Support Opportunities: Scholarships in Brazil - Post-Doctoral