Photocatalytic Oxidation Of Municipal Sewage In A Continuous Flow Reactor Packed With Silica-titania Composites

As an excellent photocatalytic material, Nano-Ti O2 has a significant effect on the photocatalytic degradation of organic pollutants in water. It is the focus of scientists at home and abroad in recent years.In this article, nano-Ti O2 was prepared by hydrothermal method. The X-ray diffraction(XRD) indicates that the product prepared by hydrothermal method is anatase Ti O2. The result of scanning electron microscopy(SEM) show that the product is hollow polyhedron Ti O2 and the size of hollow polyhedron Ti O2 is 300 nm. The HF added too much will corrode polyhedral structure of Ti O2 that is observed by scanning electron microscopy(SEM). Photocatalytic properties of the preparated nano-Ti O2 is evaluated by degradation rate of methylene blue. The photocatalytic results indicate the prepared nanoTi O2 by adding 0.09 m LHF has the best photocatalytic properties. Comparied with P25, under the same experimental conditions, the prepared nano-Ti O2 by adding 0.09 m LHF has better photocatalytic properties.The Si O2-Ti O2 composite(STC) is synthesised by the mixture of prepared nano-Ti O2 and silica gel. The nano-Ti O2 is prepared by hydrothermal method. And silica gel is prepared by the hydrolysis of tetraethoxysilane. Different Ti O2 content of Si O2-Ti O2 composites that contains 0.01, 0.10, 0.30, 0.50 and 0.70 STC is prepared by changing the amount of Ti O2.The result of X-ray diffraction(XRD) on Si O2-Ti O2 composites show that Si O2 and Ti O2 composite well. The surface area of Si O2-Ti O2 composites is measured by nitrogen adsorption-desorption(BET). With the increase of the content of Ti O2, the specific surface area of 0.01, 0.10, 0.30, 0.50 and 0.70 STC decrease from 404 m2 / g to 236m2 / g. Changes in the concentration of substances in municipal sewage is measured by TOC tester using STC as photocatalyst. Among the different Ti O2 content of STC contained 0.01、0.10、0.30、0.50 and 0.70, the 0.30 STC exhibits the best degraded effect for municipal sewage.