Electrochemical oxidation treatment of Direct Red 23 aqueous solutions: Influence of the operating conditions

• Published in: Separation science and technology Vol. 57; no. 9; pp. 1501 - 1520
• Main Authors: Titchou, Fatima Ezzahra, Zazou, Hicham, Afanga, Hanane, El Gaayda, Jamila, Ait Akbour, Rachid, Lesage, Geoffroy, Rivallin, Matthieu, Cretin, Marc, Hamdani, Mohamed
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 13.06.2022; Taylor & Francis Ltd
• Subjects: Anodes; Aqueous solutions; Boron; Carbon; Catalysis; Cathodes; Chemical Sciences; Comparative analysis; Comparative studies; Current density; Degradation; Diamonds; Dimensional stability; Dimensionally stable anodes; Direct Red 23 dye; Dyes; Electrochemical oxidation; Electrochemistry; Electrolysis; Electrolytes; Electrolytic cells; Electrooxidation; Kinetics; mineralization; Organic carbon; organic degradation; Oxidation; Sodium chloride; Sodium sulfate; Stainless steel; Stainless steels; Total organic carbon; wastewater treatment; Electrooxidation; organic degradation; mineralization; Direct Red 23 dye; wastewater treatment
• ISSN: 0149-6395; 1520-5754
• DOI: 10.1080/01496395.2021.1982978

A comparative study of the degradation of Direct Red 23 (DR23) dye aqueous solutions by electrooxidation was investigated using different anodes: carbon graphite (CG), dimensionally stable anode (DSA), Magnéli phase Ti 4 O 7 , and boron-doped diamond (BDD). Stainless steel (SS) and CG plates were tested as cathodes. The effect of operating parameters on the degradation kinetics of the dye was studied. In this study, NaCl and Na 2 SO 4 were selected as supporting electrolytes; the former was found to be more suitable for the degradation of DR23. The degradation of the dye follows a pseudo-first-order kinetics in both media. Higher total organic carbon (TOC) efficiency was achieved by BDD/CG cells. Thus, the treatment efficiency obtained using a current density of 5 mA cm −2 , and DR23 concentration of 60 mg L −1 was about 86% using both NaCl and Na 2 SO 4 electrolyte, at 6 h electrolysis time. The energy consumptions per g TOC removed were found to be 2.05 and 2.6 kWh g −1 TOC in NaCl and Na 2 SO 4 electrolytes, respectively.