Degradation of Acid Red 18 in an aqueous environment by TiO_2/Zeolite nano photocatalyst

In this study, the TiO_2 nanoparticles were supported on Y-type zeolite as a new photocatalyst and used to degrade Acid Red 18 in an aqueous environment. The nano photocatalyst was synthesized by coprecipitation procedure and characterized by Fourier transfer infrared (FTIR), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The central composite design (CCD) was employed for the design of the experiment. The effect of operative variables including photocatalyst dosage, contact time, and pH was studied. The ANOVA (analysis of variance) studies displays the second-order regression model with R^2 = 0.9953, R^2pred = 0.9642, R^2adj = 0.9910, for the destruction of AR18 was obtained. The contour plots were applied to study the shares of each parameter with mentioned interactions on the degradation of AR18. The optimal circumstances predicted by the model were as the following: the catalyst concentration at 0.88g/L, pH at 6.5, and contact time in 125 min. In this situation, the predicted and actual dye removal were 98.5% and 96.3%, respectively. The removal of COD (chemical oxygen demand) after 125 min was 53% indicating, the notable performance of photocatalyst in mineralization of AR18.