Chemometrics approach for determination and optimization of simultaneous photooxidative decolourization of a mixture of three textile dyes

In this paper simultaneous photooxidation of three textile dyes (CI Basic Red 46 (BR46), Malachite Green (MG) and CI Basic Blue 3 (BB3)) by UV/H ₂O₂ process is reported. A rapid analytical methodology based on recording UV-Vis spectra during the photooxidative decolourization process and the data treatment using multivariate curve resolution with alternating least squares (MCR-ALS) was developed. The three textile dyes were quantified simultaneously despite the overlap of their spectra. Also, the central composite design was applied for optimization of the photooxidative decolourization of the solution containing three dyes using the UV/H ₂O₂ process. The investigated factors (variables) were the reaction time, initial concentration of the three dyes and initial concentration of H₂O₂. The optimum initial concentration of the three dyes, H₂O₂ initial concentration and reaction time were found to be 4mg/L, 48mg/L and 30min, respectively. The photodegradation products of three dyes were identified by the GC-MS technique.