The photocatalyst TiO2/SiO2 was prepared and used for chlorine dioxide photocatalytic oxidation of simulated fuchsine wastewater under UV irradiation. The removal efficiency of fuchsine treated by photocatalytic oxidation process is higher than that of chemical oxidation process. By using UV-Vis and online FTIR analysis technique, the intermediates during the degradation process were obtained. The benzene ring in fuchsine was degraded into quinone and carboxylic acid and finally changed into carbon dioxide and water during the photocatalytic oxidation. The degradation reaction mechanism of fuchsine by UV irradiation chlorine dioxide photocatalytic oxidation was proposed based upon the experiment evidence. 1. Introduction The effluents produced by some of our industries are harmful to the health and general well-being of man. When undesirable substances are present in liquid effluents, it can be disastrous as their presence pose severe threat to the immediate recipients. Wastewaters from various industries, factories, laboratories, and so forth are serious problems to the environment. Addressing these problems calls out for a tremendous amount of research to be conducted to identify robust new methods of purifying water at lower cost and with less energy, while at the same time minimizing the use of chemicals and impact on the environment [1]. In recent years, a variety of wastewater treatment techniques have been applied to degrade and remove refractory materials from wastewaters, including chemical oxidation [2], biodegradation [3], electrochemical oxidation degradation [4], catalytic oxidation degradation [5, 6], and so on. Also, to obtain a high removal efficiency of hazardous materials, a combination of physical and chemical techniques should also be employed [7]. These wastewater treatment processes generate very toxic wastewater, whose treatment is often difficult due to the presence of some non-biodegradable species with complex structure. Hence there is considerable current interest in developing alternative and more cost-effective methods to treat those refractory materials. Advanced oxidation processes (AOPs) have been developed to meet the increasing need of an effective wastewater treatment. AOP generates powerful oxidizing-agent hydroxyl radicals which completely destroy major classes of organic pollutants at ambient conditions. The combination of UV irradiation with photocatalysts is one of such methods which have attracted considerable attention in recent years, due to its effectiveness in mineralization (i.e., conversion to inorganic
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