Using central composite experimental design to optimize the degradation of real dye wastewater by Fenton and photo-Fenton reactions

• Published in: Dyes and pigments 2014-01, Vol.100, p.184-189
• Main Authors: Torrades, Francesc, García-Montaño, Julia
• Format: Article
• Language: English
• Subjects: Advanced oxidation processes; Central composite design; Chemical oxygen demand reduction; Degradation; Dyes; Enginyeria química; Fenton; Indústria dels processos químics; Indústries químiques; Oxidation-reduction reaction; Photochemical reactions; Pigments; Química tèxtil; Reacció d'oxidació-reducció; Real dye wastewater; Residus; Textile chemistry; Textiles; Waste water; Wastewater treatment; Àrees temàtiques de la UPC
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2013.09.004

This work focuses on the use of Fenton reagent and UV-irradiation, in a lab-scale experiment, for the treatment of real dye wastewater coming from a Spanish textile manufacturer. Response surface methodology and a 23 factorial design were used to evaluate the effects of the three independent variables considered for the optimization of the oxidative process: temperature, Fe (II) and H2O2 concentrations, for a textile wastewater generated during a dyeing process with chemical oxygen demand of 1705 mg L−1 O2 at pH = 3. Wastewater degradation was followed in terms of chemical oxygen demand reduction. In the optimization, the correlation coefficients for the model (R2) were 0.985 and 0.990 for Fenton and photo-Fenton treatments respectively. Optimum reaction conditions at pH = 3 and temperature = 298 K were [H2O2] = 73.5 mM and [Fe(II)] = 1.79 mM. The combination of Fenton, Fenton-like and photon-Fenton reactions has been proved to be highly effective for the treatment of such a type of wastewaters, and several advantages for this technique arise from the study. Under optimum conditions, 120 min of treatment resulted in a 62.9% and 76.3% reduction in chemical oxygen demand after Fenton and photo-Fenton treatments respectively. •Fenton and photo-Fenton degrade successfully real dye wastewater.•Response surface methodology is a suitable method to optimize the operating conditions in real dye wastewater removal.•62.9% and 76.3% chemical oxygen demand reduction are attained under optimum Fenton and photo-Fenton conditions.