Screening Refractory Dye Degradation by Different Advanced Oxidation Processes

Screening Refractory Dye Degradation by Different Advanced Oxidation Processes

This study investigated Rhodamine B (RhB) degradation by electro-Fenton (EF), anodic oxidation (AO), and their combination (EF/AO), using a carbon felt cathode coupled to a sub-stoichiometric titanium dioxide Magnéli phase (Ti<sub>4</sub>O<sub>7</sub>) anode or a platinized t...

Full description

Saved in:
Bibliographic Details
Main Authors: Imane Ouagued, Marc Cretin, Eddy Petit, Geoffroy Lesage, Abderrahmane Djafer, Abdallah Ouagued, Stella Lacour
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Molecules
Subjects:
electrochemical advanced oxidation processes
electro-Fenton
anodic oxidation
coupling process
ecotoxicity
mineralization
Online Access:https://www.mdpi.com/1420-3049/30/3/712
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study investigated Rhodamine B (RhB) degradation by electro-Fenton (EF), anodic oxidation (AO), and their combination (EF/AO), using a carbon felt cathode coupled to a sub-stoichiometric titanium dioxide Magnéli phase (Ti<sub>4</sub>O<sub>7</sub>) anode or a platinized titanium (Ti/Pt) anode. The results indicated that operational parameters influenced the kinetics of electrochemical reactions. An increase in current density from 10 to 50 mA cm<sup>−2</sup> significantly enhanced the RhB degradation rate; 30 mA cm<sup>−2</sup> was the optimal current density, balancing both energy efficiency and degradation performance. Moreover, higher RhB concentrations required longer treatment. The Microtox<sup>®</sup> bioluminescence inhibition test revealed a significant toxicity decrease of the dye solution during electrochemical degradation, which was highest with EF/AO. Similarly, total organic carbon removal was highest with EF/AO (90% at pH 3), suggesting more efficient mineralization of RhB and its by-products than with EF or AO. Energy consumption remained relatively stable with all oxidation processes throughout the 480 min electrolysis period. High-resolution mass spectrometry elucidated RhB degradation pathways, highlighting chain oxidation reactions leading to the formation of intermediates and mineralization to CO<sub>2</sub> and H<sub>2</sub>O. This study underscores the potential of EF, AO, and EF/AO as effective methods for RhB mineralization to develop sustainable and environmentally friendly wastewater treatment strategies.
ISSN:1420-3049

Similar Items