The Research Of Degrading Organic Contaminants In Water Using Nanometer Tatiana

Environmental pollution has become a serious and global problem with the development of industry. The photocatalysis of the semiconductive materials appears to be a promising technology for applications in environmental systems, chemical industries and solar cells. Up to now, nanometer size titania remains the best heterogeneous photocatalyst which have been found. Because of its simplicities, economic advantages and without the second pollution, TiO2-based heterogeneous photocatalysis has the potential to degrade environmental pollutants by solar energy. The paper discusses the principle and mechanism of photocatalysis on TiO2, the methods for enhancing the efficiency of photocatalytic and existing problems on degradation of several kinds of contamination. The recent developments in TiO2 photocatalysis and its application prospects for the treatments of wastewater are also introduced.In this thesis, three matters are studied on improving the efficiency of photo degradation in details:1. Photocatalytic decoloration and degradation of methylene blue by the suspension of nano TiO2 powder irradiated by ultraviolet and visible light are investigated. Langmuir Kinetics, the rate of decoloration and degradation of the different addition of H2O2 and the value of pH were studied in details. The rate of decoloration and degradation grows up significantly with the increase of pH value and the quantity of H2O2 in definite range.2. TiO2 thin electrodes are prepared by sol-gel method. The electro-assisted photocataltic system that has two kinds electrodes (the working electrode is TiO2 thin electrode and the counter electrode is a net of stainless steel) is built. Application of the anodic bias can restrain the reposition of photogenerated electron and hole, thus the photocatalytic efficiency of TiO2 is improved. The electrochemical results show that the TiO2 thin electrode exhibited the higher electrocatalytic activity.3. A new reactor system is designed to combine the coagulation process to with the enhanced electro-assisted photocatalysic reactor and treat pharmarmaceutical industry wastewater. In the UV-light irradition, after being treated by the system, the concentration of COD of wastewater decreases by 20000 mg/L. The system can treat the wastewater of higher organic concentration.