Research On The Rehabilitation Of Environmental Organic Pollution By Modified Floating Photocatalytic Materials

The light weight and porous characteristics of expanded perlite were combined with highly photocatalytic activity for the rehabilitation of environment contaminated by organic pollutants. Different floating photocatalysts including TiO2-EP, Fe3+-TiO2-EP and Ag+-TiO2-EP were successfully synthesized by Sol-Gel method using tetrabutyl titanate as precursor and expanded perlite (EP) as support. The structural characterizations of different materials (Fe3+-TiO2-EP, Ag+-TiO2-EP, TiO2-EP, EP) were carried out by SEM, XRD and UV-vis, which objective grasp the changes of these materials according to comparison of different structural properties. Under simulated sunlight condition, photocatalytic degradation of organic pollutants contain phenol and petroleum in soil as well as methyl orange in water by different materials, and relevant factors affecting degradation effect were studied.The main results show as follows:(1) Anatase TiO2were prepared and loaded successfully to EP.(2) EP had little ability to remove the methyl orange from water, while EP modified with surfactant Ag+-TiO2or TiO2could remove methyl orange significantly. Materials with different content of Ag+had a relatively significant impact on the degradation of methyl orange. The materials contained0.04mol%Ag+showed higher degradation to methyl orange than whose do not contained Ag+. The results also showed that Ag+-TiO2-EP modified three times has the better degradation of methyl orange than TiO2-EP. The initial concentration as well as the dosage and degradation time had marked effect on the degradation of methyl orange. The recycling time of Ag+-TiO2-EP produced certain effect on photocatalytic activity. After three times recycling, the degradation rate of methyl orange was24.8%. (3) The adsorption time as well as degradation time had significant impact on the degradation effect of phenol. Basing on the former single factor experiments, the degradation condition was optimized by taguchi method. Under optimized condition, the photocatalytic ability of Fe3+-TiO2-EP material which modified three times with Fe3+-TiO2(0.02mol%Fe3+) is significant better than the others (TiO2-EP, EP). Fe3+-TiO2-EP material still had the relatively higher photocatalytic activity after three times recycling and the degradation rate of phenol was19.49%.(4) Initial concentration of petroleum, adsorption time and degradation time had effect on the photocatalytic degradation of petroleum in soil. Comparing with TiO2-EP, Fe3+-Ti02-EP material show higher photocatalytic ability in the degradation of petroleum existed in soil. Fe3+-TiO2-EP material could maintain good photocatalytic activity after four times recycling.