The Preparation And Photocatalytic Property Of Nano TiO₂/4A Zeolite Composite

Photocatalytic technology is one of the most potential methods to deal withwater pollution problem in such treatments. This paper gives an overview of thedevelopment in TiO₂ photocatalyst, performance of zeolite and the advantages ofTiO₂/4A zeolite composite. TiO₂ based photocatalysts were prepared by impregnating4A zeolite using a sol-gel technique in this study. Taking after-one-hour degradationrate of methyl orange as an evaluation standard to discuss the optimal preparationconditions through orthogonal tests. The optimal preparation conditions are ones withthe 4A zeolite particle size -200 meshes, the volume ratio between tetrabutyl titanateand absolute ethanol at 1:1, the TiO₂ load 12%, the pH 4.51, and the calcinationstemperature 500℃, where the after-one-hour degradation rate of 20 mg/L methylorange reaches 100%. The characteristics of the composite determined by TG-DTA,XRD, CEC, IR, Raman, SEM and EDS have shown that 23nm anatase TiO₂ wascarried on the surface of zeolite in Ti-O-Si. Using degradation rate of dying wastewater from Ningbo Shenzhou Dying and Coloring Factory as an evaluation standardto research the relationship between photocatalyst concentration, water dilutingmultiples, initial pH value of waste water, repetition of photocatalyst, irradiation time,different catalysts and the COD degradation rate. The COD degradation rate can reach45.69% and the tinct of waste water comes out by and large. Using dynamic equationto discuss the photocatalytic curves, we can see the dynamic characteristics ofcomposite under the optimal preparation conditions, and the velocity constant ofdynamic equation between 0h³h is 0.1094h^-1.