Photo-Fenton oxidation of Orange G azo dye: process optimization and mineralization mechanism
Textile effluents containing synthetic dyes are one of the most important sources of water pollution. Several dyes are toxic to the aquatic life and indirectly to humans, and therefore should be treated before rejection to natural water streams. As conventional wastewater treatment systems remain inefficient for treatment of these recalcitrant pollutants, the use of advanced oxidation processed is required. The degradation of the Orange G dye was studied using the photo-Fenton process. Results showed that the use of experimental kinetics rate constants to optimize the ratio R = [H2O2]/[Fe3+] constitutes a suitable way to minimize the occurrence of side reactions. An optimal molar ratio R of 13.8 was found allowing complete degradation of Orange G in 4 min and 93.41% total organic carbon (TOC) removal in 180 min. Based on detected intermediates and end-products, a plausible degradation mechanism of Orange G dye is proposed. Therefore, we demonstrated that the photo-Fenton process can be applied efficiently to the removal of toxic/persistent organic pollutants such as synthetic dyes from water.
KeywordsPhoto-Fenton Orange G Mineralization By-products Degradation mechanism
The authors are grateful to the “Service de la Cooperation et d’Action Culturelle” (SCAC) at the French Embassy in Cameroon for financial support.
- Bouafia-Chergui S, Oturan N, Khalaf H, Oturan MA (2010) Parametric study on the effect of the ratios [H2O2]/[Fe3+] and [H2O2]/[substrate] on the photo-Fenton degradation of cationic azo dye basic blue 41. J Environ Sci Health A 45:622–629. https://doi.org/10.1080/10934521003595746 CrossRefGoogle Scholar
- Khandelwal DH, Ameta R (2013) Use of photo-fenton reagent for the degradation of Basic yellow 2 in aqueous medium. Res J Recent Sci 2:39–43Google Scholar
- Oturan N, Trajkovska S, Oturan MA, Couderchet M, Aaron JJ (2008b) Study of the toxicity of diuron and its metabolites formed in aqueous medium during application of the electrochemical advanced oxidation process “electro-Fenton”. Chemosphere 73:1550–1556. https://doi.org/10.1016/j.chemosphere.2008.07.082 CrossRefGoogle Scholar
- Tang WZ (2003) Advanced oxidation processes. In: Physicochemical treatment of hazardous wastes. CRC Press. ISBN: 9781566769273Google Scholar