Research On The Technology Of Preparing Ozone By Low Pressure Electrolysis

Ozone has attracted widespread attention in the fields of disinfection,deodorization and decolorization due to its strong oxidizing ability and low durability.The main disadvantages of traditional ozone production methods are the large volume of equipment and high energy consumption.In order to overcome the shortcomings of traditional ozone production methods,solid polymer electrolyte technology emerged as a new type of electrochemical ozone production technology.Due to the advantages of high ozone concentration,high energy efficiency,simple device and no secondary pollution,this technology is in line with the needs of many industries and has broad application prospects.Based on solid polymer electrolyte technology,this paper has carried out research work on the design of electrolytic ozone generator,the development of membrane electrode assembly,the optimization of ozone production process conditions and the evaluation of sterilization performance of ozone water.First,the internal structure design of the ozone generator was carried out,including the structure of the membrane electrode assembly,the structure of the electrolytic cell and the material of the current collector.The membrane electrode assembly adopts a zero-gap structure in which the electrode material and the electrolyte membrane are closely combined;the sealing gasket of the electrolytic cell is square,and the diversion area is designed with an S-shaped flow channel;the current collector is made of metal titanium.Secondly,combined with electrode characterization analysis,the influence of electrode type,composition structure,thickness and electrolyte membrane on ozone production performance was studied.The results show that when BDD electrodes with thickness of 0.52 mm and B/C ratio of 4.9 wt%are selected as the electrode materials,and Nafion 115 is used as the electrolyte membrane,the ozone production performance of the membrane electrode assembly is the best,and the optimal membrane electrode assembly is determined.Then,on the basis of the optimal membrane electrode assembly,a set of low-pressure continuous electrolysis technology was established,and the effects of current density,electrolyte flow rate,electrolyte conductivity,electrolyte p H value and reaction temperature on the performance of ozone production were investigated.Furthermore,the production conditions of ozone were optimized.The results show that when the current density is 33 mA/cm~2,the electrolyte flow rate is 15ml/min,the electrolyte conductivity is 1μs/cm,the electrolyte p H value is 7,and the reaction temperature is 55℃,the ozone production performance is the best.So as to determine the best process conditions.Finally,under the best membrane electrode assembly and the best process conditions,ozone water was produced by electrolysis and its sterilization performance was evaluated.The results show that the ozone water has a bactericidal effect on E.coli suspensions with bacterial content of 1×10~9～3×10~9 cfu/m L.Under the lower the content of organic interferences and the longer the action time,the sterilization effect is the better.And temperature and p H have little effect on the sterilization effect of ozone water.