Decolorization of a Methyl Blue Solution Using a UV/Nano-TiO_2 Particle Degradation Method Paper 2011-A- 422-AWMA

摘要

Many sources of volatile organic compounds such as aerosol paint factories use scrubbers as air pollution systems. During the scrubbing process, high concentration organic liquid wastes are produced that must be treated in order to prevent a second source of pollution. This research investigated degradation performance of methyl blue dye using photocatalyst TiO_2 nanoparticles irradiated under a 254nm wavelength ultraviolet light. The degradation efficiency, which is discussed in terms of decolorization of the methyl blue (MB) dyed water, was assessed under different initial concentration of the dyed waste water (5ppm-20ppm), TiO_2 doping amount (0.1 to 0.6g/L), pH value (3-9) and temperature (25-55 °C). The results showed that the degradation efficiency increased with decreasing in MB concentration and increasing in the doping amount of TiO_2. Lowering the pH of the dye water solution improved the degradation efficiency since the MB is weakly acidic. As the temperature was raised, the degradation efficiency initially raised and then descended. The results also showed that 45°C is the optimal reaction temperature. ANOVA analysis of the degradation efficiency relative to the tested parameters reveals that pH is the most influential experiment parameter. 100% degradation efficiency of the waste water was obtained in 40 minutes under doping amount of 0.2 g/L, reaction temperature of 45 °C and MB concentration of 10ppm. Under the same experiment conditions but using a doping value of 0.6g/L, 100 percent degradation efficiency is obtained in 16 minutes.