| Recently with the high-speed development of China economy, it has been developed continuously that a great lot of waste water appeared and the drinking water sources was very much polluted, which directly affected social production and the people's livelihood. Development and utilization of deep water treatment technology have more and more been widely attended.Wastewater treatment technology by plasma as a developing deep water treatment methods was an advanced oxidation process for wastewater treatment which was combined high-energy electron radiation, ozonation oxidation and UV-light induced photodegradation. As a new environment-purifying technique, method of semiconductor photocatalysed oxidation in degradation of organic contaminants was drawing more and more attention. It was obvious that physical and chemical effect excitation by plasma was made full use and activation energy with catalyst also effectively reduced when two methods above mentioned were used in wastewater treatment process at the same time. As a result, it promoted removal rates for the pollutants and reduced energy utilization ratio of plasma.In this study, vermiculite was used for carrier, which is a kind of porous materials possessing large specific surface area and stong absorbility. So far, research about the materials as supports was few. The material was treated by nitric acid or sulfuric acid with different concentration. It was found that the acid treatment could improve the performances of the material. Acid-treated vermiculite possessed better properties, namely were larger specific surface area and stonger absorbility. TiO2 and ZnO, which are semiconductor materials, have been used as photocatalysts and supported by acid-treated granular vermiculite. The effect of different treatment conditions on crystalline sizes and photocatalysis performance has been studied. The photocatalysts samples were investigated by used XRD, N2 adsorption analysis and scan electron microscopy. The result showed that prepared TiO2 catalysts samples were nanostructured particles and acid-treated vermiculite was mesoporous material. The treatment effect of nitric acid was superior to that of sulfuric acid. The optimal nitric acid concentration was 1:2 (v/v) condensed deionized water to nitric acid. The size of the crystal of TiO2 is influenced on support for the composite catalysts. TiO2 on the nitric acid treated vermiculite was smaller than that on the sulfuric acid treated vermiculite. The composite was easy to be reused because of high melt point and thermal stability of carrier. The nano TiO2 was prepared with sol method by the precursor, which was obtained by substituting partly isopropyl alcohol with Cl- in titanium chloride{[Ti(â…£)(OR)nClm] (n=2-3, m=4-n)}. Its phase is anatase.The solution of methylene blue as simulative contaminant was treated by UV light, plasma, plasma and prepared photocatalysts, respectively. Compared the results of treatment, it was found that the substrate was concentrated by adsorption of the support in composite and rate of oxide became fast. It was best when plasma and prepared photocatalysts were used in treatment process at same time. Effect of removal was best and the rate of removal was fastest. |
PDF Full Text Request