ELECTROCHEMICAL BLEACHING OF YELLOW 4GN AND BLUE 2R DYES WITH Ti/Pt

• DOI: 10.22533/at.ed.3173402323118

• Palavras-chave: electrodecoloración, colorantes textiles, oxidación avanzada, contaminación.

• Keywords: electrocoloration, textile dyes, advanced oxidation, contamination.

• Abstract:

  The growing contamination of water by textile dyes encourages the search for methodologies for their treatment, such as advanced oxidation techniques. In this work, the electrochemical behavior of the synthetic dyes yellow 4GN (A4GN) and blue 2R (A2R) used in the dyeing of Saltillo sarapes was studied using cyclic voltammetry (VC), as well as their electrochemical decolorization. For CV, a three-electrode cell was used (Pt working electrode and counter electrode, Ag/AgCl reference), 0.1 M KCl as support electrolyte and 50 mg/L sample solutions. It was observed that the oxidation of the dyes occurs, although its signal is masked by the oxidation of the chloride ion because its concentration is higher than that of the analytes. For decolorization, a sandwich flow cell with 2 Ti/Pt electrodes, 0.1 M KCl as electrolyte and 50 mg/L sample was used. The applied voltage, pH and flow rate were analyzed. Voltage, flow rate and the interaction between them were the most significant factors in the oxidative process for both dyes, while pH was not a relevant factor. The discoloration performances were 95.5% for A4GN and 96.4% for A2R, when applying 3.0 V respectively. This methodology is easy to operate and allows the reuse and/or recirculation of the water used in wool dyeing, an important artisanal activity in the manufacture of textiles.