Application the Taguchi experimental design in determination the optimal conditions the photocatalytic degradation reaction of Sunset Yellow FCF azoic pollutant using silver nanoparticles in a photoreactor

ABSTRACT: In this study, silver nanoparticles (Ag-NPs) as catalysts in the photocatalytic degradation reaction of Sunset Yellow FCF (SYF) azo dye in aqueous solution were investigated. Ag-NPs was prepared by using walnut (Juglans regia L.) leaf extract. The synthesis of Ag-NPs has been done using green chemistry, which is an environmentally friendly, low-cost, fast and safe method. Extraction was done with a facile method, as well as the synthesis of Ag-NPs in a short period of time and with high efficiency. The Ag-NPs were characterized by scanning electron microscopy (SEM), Energy dispersive X-ray (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Optimum conditions for dye degradation were determined using Taguchi experimental design method with (L9(34)) orthogonal array. Analysis the response of each experiment was based Signal to Noise (S/NL) ratio was calculated. The effects of operational parameters such as: catalyst amount, pH, irradiation time and temperature in three levels for each factor were studied. The Taguchi results showed that catalyst amount= 20 mg/l (level 2), pH= 4 (level 1), irradiation time = 45 min. (level 3) and temperature= 30 °C (level 3) was optimum conditions for this process. The most influenced of each factor on the process determined using Analysis of Variance (ANOVA) method. The most significant factor in this process was pH. The interaction between pH×catalyst amount was the most influencing interaction. The analysis of primary ANOVA showed that percent (p(%)) parameters was: catalyst amount (12.002%), pH (46.298%) , irradiation time (35.311%) and temperature (6.383%). The contribution of factors in this process was found to be in the following the order: catalyst amount (0.142), pH (0.431), irradiation time (0.397) and temperature (0.18). A pseudo-first-order kinetic reaction with rate constant k=0.0721 min−1 was observed for dye photocatalytic degradation.