Abstract:
In order to improve the degradation efficiency of organic compounds and reduce energy consumption for the reaction system by using the ozone (O
3) and ultra violet radiation (O
3/UV) technique, based on the SHB mechanism of O
3 decomposition and photolysis mechanism of O
3 and organic compounds UV radiation, a kinetic model of O
3/UV reaction system was established by studying 3 possible degradation pathways of organic compounds and the concentration change of gas phase O
3. The model was used to study the change rules of digestion rate for organic compounds during the degradation process and further to optimize the degradation conditions. Taking phenol and acetic acid as the target organic compounds to conduct the simulation, the sensitivity of the kinetic model to different reaction conditions and the synergy between O
3 and UV were verified theoretically. The superiority and accuracy of the proposed model was confirmed via comparison with other kinetic models and actual measurements in digestion experiments. The simulation results for the respective contribution rates of three degradation pathways under different pH values demonstrated the importance of pH value in this reaction system. This study illustrates that there is a synergy between the UV radiation intensity and O
3 concentration in the O
3/UV system, and high digestion rate can be obtained when they are adjusted together; organic compounds are directly oxidized by O
3 under acidic conditions, and by radicals under alkaline conditions.
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