Investigation of TiO 2 /zeolite photocatalytic activity for Safranin dye removal of aqueous solution

Abstract

Aims: This study was aimed to determine the TiO 2 /zeolite photocatalytic activity for removing red Safranin dye form aqueous phase. Materials and Methods: In this study, TiO 2 nanoparticles were produced using sol-gel method and 2.5 ml sol-gel was coated on 1.2222 g of zeolite. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to specify the structure and morphology of TiO 2 nanoparticles. The effect of TiO 2 coating on zeolite, ultraviolet (UV) radiation intensity, initial concentration of dye and the type of photocatalyst substrate (fixed and moving) on photocatalytic process was investigated. Results: According to XRD results, the TiO 2 nanoparticles had two phases including anatase (80.5%) and rutile (19.5%). The uniformity of nanoparticles was obvious in the SEM images. The removal efficiency of TiO 2 coated on zeolite was higher than TiO 2 photocatalysis with increasing UV radiation intensity from 2.4 w/m 2 to 3.9 w/m 2 , the photocatalytic efficiency was also enhanced. The removal efficiency decreased from 91.61% to 77.91% by increasing the red Safranin dye concentration from 10 mg/L to 50 mg/L. The moving bed of TiO 2 /zeolite photocatalyst had a higher efficiency than the fixed bed. Conclusion: In over all, the TiO 2 /zeolite photocatalyst was much more effective than TiO 2 photocatalyst for Safranin dye removal from the aqueous phase. With increasing UV radiation intensity and decreasing dye concentration photocatalytic efficiency, was improved. TiO 2 /zeolite photocatalyst with fixed bed is recommended to be used in water treatment. The most important problem of using moving-bed TiO 2 /zeolite photocatalyst in the water treatment is opacity.