Study on the Photocatalytic Degradation of Wastewater under the Optimal Preparation of the Activated Carbon Supported TiO2 Thin Film

Abstract

Textile industries usually discharge colored effluents containing various dyes. These dyes usually contain more than one aromatic structure and they are not only difficult to be degraded biologically but also toxic. UV/semiconductor procedure, with advantages including photostability, non-toxicity, affordable price, and insolubility in water, has been studied and used. This aim of this study is to develop photocatalytic reactor with higher removal efficiency. The TiO2 thin film was prepared by Sol-Gel method and coated on the surface of activated carbon to enhance the reaction opportunity and increase pollutants removal efficiency. Taguchi method was used to optimize preparing conditions. The results indicated that the best TiO2 photocatalytic activity can be found when tetraisopropyl orthotitanate, isopropyl alcohol and acetic acid were mixed in the molar ratio of 1：2：8 under the calcination temperature of 500°C for 90 minutes. Further analysis of TiO2 thin film by SEM, ESCA and XRD, the results showed that grain size of TiO2 was about 17 nm and crystal structure mainly was anatase. The photocatalytic reaction rate increased 15~20% when the ratio of PAC in catalyst increased > 4%. The results suggested that recovery of the composited catalyst become easy because its volume and subsiding increased.