Water, Air, & Soil Pollution

, 224:1397

Electrochemical Degradation of the Reactive Red 141 Dye Using a Boron-Doped Diamond Anode

  • José Mario Aquino
  • Romeu C. Rocha-Filho
  • Manuel A. Rodrigo
  • Cristina Sáez
  • Pablo Cañizares
Article

DOI: 10.1007/s11270-012-1397-9

Cite this article as:
Aquino, J.M., Rocha-Filho, R.C., Rodrigo, M.A. et al. Water Air Soil Pollut (2013) 224: 1397. doi:10.1007/s11270-012-1397-9

Abstract

The electrochemical degradation of the Reactive Red 141 azo dye was done using a one-compartment filter-press flow cell with a boron-doped diamond anode. The response surface methodology (with a central composite design) was used to investigate the effect of current density (10–50 mA cm−2), pH (3–11), NaCl concentration ([NaCl]) (0–2.34 g L–1), and temperature (15–55 °C) on the system’s performance. The charge required for 90 % decolorization (Q90), the fraction of chemical oxygen demand removal after 6 min of electrolysis (COD6), and the fraction of total organic carbon removal after 90 min of electrolysis (TOC90) were used to model the obtained results. The lowest values of Q90 were attained at pH <4 in the presence of higher values of [NaCl] (>1.5 g L−1), due to the electrogeneration of active chlorine, present mainly as HClO. The value of COD6 was not affected by the solution pH, but increased with [NaCl] up to 1.5 g L−1. Higher temperatures (>40 °C) led to a decrease in COD6, as a consequence of side reactions. Higher values of TOC90, which can be reached only with strong oxidants (such as ·OH and Cl·), were efficiently attained at low [NaCl] values (<0.7 g L−1) in acidic solutions that inhibit the formation of ClO3 and ClO4. Finally, the obtained results allow inferring that most probably the mineralization of the dye starts with an attack on the chromophore group, followed by the degradation of intermediate species.

Keywords

Response surface methodologyConductive-diamond anodeElectrochemical oxidationDye mineralizationDye electrooxidationChloride mediated oxidation

Supplementary material

11270_2012_1397_MOESM1_ESM.pdf (2.1 mb)
ESM 1(PDF 2.10 mb)

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • José Mario Aquino
    • 1
  • Romeu C. Rocha-Filho
    • 1
  • Manuel A. Rodrigo
    • 2
  • Cristina Sáez
    • 2
  • Pablo Cañizares
    • 2
  1. 1.Department of ChemistryUniversidade Federal de São CarlosSão CarlosBrazil
  2. 2.Department of Chemical Engineering, Facultad de Ciencias QuímicasUniversidad de Castilla La ManchaCiudad RealSpain