Application of response surface methodology for optimization of removal sunset yellow from aqueous by Granular Ferric Hydroxide (GFH)

Color is the first pollutant that is detected in wastewater and can be discharged into the wastewater through various industries. Sunset yellow is an azo dye that is used in the food, health and pharmaceutical industries. Due to its low price and good quality, this color is used in industries more than natural colorants. The aim of this study was to investigate the effect of granular ferric hydroxide (GFH) on the removal of sunset yellow color from aqueous solution using the response surface methodology (RSM). In this study, GFH was employed to remove sunset yellow dye from the aqueous solution. Due to saving time, cost and getting to the optimum conditions, the effect of important factors on adsorption was optimized by the RSM. The morphology of the adsorbent was determined by scanning electron microscopy. The results revealed that optimum conditions for sunset yellow removal by GFH with design experiment were dye concentration= 24 mg/L, GFH dose= 2.4 g/L, reaction time= 25 min. In addition, based on the results, the best-fitted model for this study was the quadratic model (R2 =0.966, R2adj=0.79 and R2 pred=0.936). According to the obtained results, GFH was successful in sunset yellow removal. Therefore, it is suggested to use this process to remove sunset yellow from aqueous solutions.