Study On Photocatalytic Degradation Of Rhodamine B With TiO₂ Supported On Zeolite L

With the rapid development of textile and dyeing industry, water pollution is becoming more and more serious. Because of dyeing wastewater containing the stable structure of organic compounds such as benzene, so it is hard to biodegrade. TiO₂ photocatalytic technology was able to put these organic pollutants which are difficult to biodegrade in ore into harmless small molecules such as CO₂ and H₂ O. In order to further improve the photocatalytic activity of TiO₂, this paper conducted a research on the photocatalytic degradation of Rhodamine B with TiO₂ supported on zeolite L.Choosing potassium feldspar powder from Anhui Yuexi and white carbon black as raw materials, using hydrothermal method synthesized zeolite L. The TiO₂/zeolite L photocatalysts were obtained by a sol-gel method. The TiO₂/zeolite L photocatalysts were characterized with X-ray diffraction（XRD）, scanning electron microscopy（SEM）, infrared spectrum（FTIR）.The properties of TiO₂/zeolite L photocatalysts were performed by degrading of Rhodamine B under the xenon lamp irradiation. By examining different preparation conditions on the degradation rate of rhodamine B such as the loading methods,heat treat temperature, TiO₂ amount on zeolite L to obtain the optimized preparing conditions: choosing B method, heat treatting temperature of 300℃, TiO₂ amount on zeolite L of 50%.The effect of catalyst amount, solution pH, initial concentration, visible light and xenon lamp on the photocatalytic activities were studied. The results show that when the initial solution pH value is 6, composite photocatalyst inputs for 4 g/L, the photocatalytic activitie was better. And under the condition of the optimization, the degradation of rhodamine B rate can reach 98.7%. Visible light and xenon lamp light contrast experiment results showed that the degradation of xenon lamp role better than visible light, visible light has certain contribution to the degradation of Rhodamine B.The influence of catalyst using times was also studied. The results showed that the TiO₂/zeolite L catalysts used in four times still has high catalytic activity. In TiO₂/zeolite L suspension system, the reaction kinetics law of the photocatalyticdegradation of rhodamine B were studied. It was found that the procedure of photocatalytic degradation of rhodamine B followed the first order kinetic relationship and their reaction rate constants was 0.0173min-1. Finally, other organic compounds such as methyl orange, methylene blue on the photocatalytic activities were also studied, the results showed that the TiO₂/L zeolite catalyst for methyl orange has good degradation, degradation rate can reach 82%, but for methylene blue is mainly adsorption.