Photocatalytic oxidation of ammonia over cadmium sulfide / titanate nanotube synthesized via microwave irradiation

• Main Authors: Chih-Hao Chen, 陳志豪
• Other Authors: 駱尚廉
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/03961369883965305044

碩士 === 國立臺灣大學 === 環境工程學研究所 === 95 === Abstract Aqueous ammonia (NH3/NH4+) is a major nitrogen-containing pollutants in wastewater. Its existence will be toxic to aquatic life and will cause fishes die. When there is high amount of ammonia in natural water, it will reduce the effect of disinfection in the treatments of tap water. Currently, there are some treatments for ammonia removal like biological nitrification, ammonia stripping, break-point chlorination and ion exchange. The photocatalytic reaction has been proved that it is an effective and a feasible method for ammonia removal . When photocatalysts are under UV illumination, the excited electron will follow a series of reaction and will produce the hydroxyl radicals (OH∙) which possess high ability of oxidation and then the ammonia will be oxidized. The cadmium sulfide and titanate nanotubes (TNTs) were prepared by microwave hydrothermal method in this research, the efficiency of ammonia removal by using photocatalysts under different microwave conditions were also investigated. The control factors include temperature, irradiation power and Cd/S ratio. In addition to examining the effects of ammonia by the above factors, we also cooperate with the physical analysis like particle size analysis, pore volume analysis, specific surface area, SEM/EDX, XRD to make some assistant descriptions. However, the ion exchange ability of TNTs were also determined. When there are CdS/TNTs in our photocatalytic system, the efficiency of ammonia removal was better than either only CdS or TNTs in the photocatalytic system. The result can be due to the interparticle electron transfer (IPET). Moreover, the ion exchange ability of TNTs decreased with the irradiation power increased.