| Because of the powerful oxidation capability, no producing more toxic compounds than removed ones and neither introducing foreign matter to the medium, ozonation is an ideal technique to deal with the organic pollutants in aqueous and has been applied in COD determining. Advance oxidation processes (AOPs) referring to ozonation are the cooperation of ozonation and other oxidative means, which have been proved that it has a more powerful oxidation capability than that of ozonation alone. For example, a certain organic compound can hardly be degraded by ozonation alone, but a combination of both ozone and UV irradiation (UV/O3) or ozonation combining with semiconductor photocatalysis can improve the oxidation efficiency. It indicates that AOPs referring to ozonation should be a more prospective oxidant applied in COD determining than ozonation alone. This work studied in detailed the ozonation kinetics of phenolic compounds and their ozonation reaction mechanisms under the UV irradiation, developed a new method to determine chemical oxygen demand (COD) utilizing the oxidation technique of UV/O3 and applied this method successfully in determining of natural water samples. The dissertation consists of 6 parts: (1) A review of the application and development of the ozone technique, AOPs and the methods for determining COD. (2) Developing a new method for determining ozone in aqueous (D03) based on the ozone oxidative flow injection chemiluminescence (FI-CL) reaction. (3) the study for determining COD of the phenolic compounds utilizing flow injection chemiluminescence (FI-CL) analysis method based on the UV/O3 process. (4) Investigating of the ozonation kinetics processes andozonation reaction mechanism of the phenolic compounds. (5) Determining COD of natural water samples collected from different area using the FI-CL method. (6) the investigation for the oxidation capability of Os/UV combining with TiO2 photocatalysis (Oa/UV/TiO2) and the discussion of the application of O3/UV/TiO2 in COD determining.In the first chapter of the thesis, more than 100 references were reviewed and the background of the research was given. The properties, generation methods, applications and monitoring for ozone in aqueous were introduced in detailed. The oxidative principle and application points referring to AOPs were reviewed. The status quo and development of the COD determination were discussed. The intending foreground for COD determining was prospected. In the end of this chapter, the new method for COD determining based on the oxidation technique of Oa/UV was put forward.In chapter 2, A new method for determining DO3 was built based on the phenomena that luminol can be oxidized by DO3 to produce luminescence. The experimental results show that the concentrations of DO3 have a linear relationship with the integral of the CL intensity within 100s. By this linear relationship, the unknown concentrations of DO3 of a certain water sample could be gained by measuring its CL intensity. The DO3 concentration of a drinking water sample is 0.818mg/L measured by FI-CL method and RSD is 8.54%. Compared with the result of 0.843mg/L measured by the indigo method, there is a recovery of 97.03%. By adding Co2+, the interference of CL catalyzed by trace metal existing in aqueous was sheltered effectively. NaHCO3, as the OH free radical scavenger, was introduced into the FI system to eliminate the CL that was produced by the oxidation of ?OH.ITIn the third chapter, A new method for determining COD was developed based on the measurement of DO3 depicted in chapter 2. The oxidation means of UV/O3 was applied and the changes of the DO3 concentration in solutions were inspected by CL detector. The working curve for the COD determination was gamed by measuring the CL signals of the different concentrations of potassium biphthalate solutions. Several phenolic compounds were oxidized by UV/O3 and the results of their COD can be gained by calculating the consumption of DO3.In chapter 4, the ozonation kinetics processes and ozonation mechanism...
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