Study On Catalytic Ozone Advanced Oxidation Treatment Of Organic Wastewater And Efficient Reactors

The distribution of water resources in China is uneven and extremely scarce.In order to better use and save water resources,it is particularly important to realize the purification and recycling of wastewater.Industrial wastewater is the main source of wastewater in the environment,which contains a large number of organic pollutants,most of which have aromatic rings,and have certain toxicity to the environment and human body.Therefore,it is urgent to find a method that can effectively degrade organic pollutants in water.In this paper,we mainly studied the calcium-based catalyst and reactor for catalytic ozonation of organic wastewater containing aromatic ring,and explored the catalytic mechanism and process conditions.Firstly,Zn O doped Ca₂Fe₂O₅catalyst was prepared by sol-gel method and equal volume impregnation method,and was used to degrade 1-butyl-3-methylimidazole chloride（BMIMCl）ionic liquid.It can be seen that after 120 min of reaction,the Chemical oxygen demand（COD）degradation efficiency of BMIMCl can reached 92%,which was significantly higher than that of ozone oxidation alone.The strong interaction between calcium and iron improved the stability of calcium-based catalysts.The repeatability experiment showed that the Zn O doped Ca₂Fe₂O₅catalyst had good stability.However,in the process of ozone oxidation,the available ozone was very low.Therefore,improving the utilization efficiency of ozone was the key to improved the economic benefits of this process.Improved gas-liquid interphase mass transfer was an effective means to improved the ozone utilization efficiency.The design of an efficient reactor for catalytic oxidation treatment of organic wastewater provides theoretical support for the design of advanced oxidation process.In order to find out the key factors that affect the efficiency of the reactor and the design of the high-efficiency reactor,the macro-kinetics of the degradation of phenol and backmixing by Ca O catalyzed ozone was studied using batch reactor（BSTR）,total mixed flow reactor（CSTR）,tower reactor,folded plate reactor and microtube reactor.The results of chemical absorption enhancement factor（β）showed that the dissolution rate of ozone from atmosphere to solution was the key factor in this process.The residence time distribution（RTD）experimented on different reactors showed that the backmixing was another major factor that hindered the catalytic oxidation rate.In order to improved the solubility of ozone and reduced the influence of backmixing,microtubule reactor was selected.Compared with the bubble reactor,the solubility of ozone was increased by more than 2 times.The reaction conditions were optimized.The COD removal efficiency of the micro-tube reactor can reached 100%in 1.01 minutes.The utilization efficiency of O₃was up to 84%.The experimental results showed that the prepared calcium-based catalyst can effectively catalyze the degradation of organic pollutants by ozonation and has high catalytic activity.An efficient reactor for catalytic oxidation treatment of organic wastewater was designed to significantly improve the utilization efficiency and reactivity of ozone.This paper provides a theoretical basis and design method for catalysts and reactors for catalytic oxidation treatment of organic wastewater.