Study On Generation Of Hydroxyl Free Radical By UV/H₂O₂/O₃ Advanced Oxidation Technology And Its Washing Disinfection Performance

Hydroxyl free radical has strong oxidation ability,small selectivity,and can be sterilized at room temperature.It can be used for medical washing,which can greatly reduce energy consumption and will not produce secondary pollution.It meets the requirements of green environmental protection and has a good application prospect.Focusing on UV/H₂O₂/O₃system,this topic focuses on the production of hydroxyl free radical in UV system and the sterilization effect after hydroxyl free radical washing medical dirty cloth,which is of great practical significance.With salicylic acid as the trapping agent of hydroxyl free radical,the production of hydroxyl free radical is obtained indirectly through hydroxyl products produced by salicylic acid reaction with hydroxyl free radical—2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid by HPLC.The washing conditions were then evaluated by the amount of hydroxyl free radicals and the bacterial changes of medical fabric before and after washing.In UV/H₂O₂/O₃system,there are three elements:UV,H₂O₂and O₃,which interact with O₃/H₂O₂reaction,UV/O₃reaction and UV/H₂O₂reaction.Through the control variable experiment,the effect of p H,H₂O₂concentration,UV wavelength,UV intensity and other variables on the hydroxyl free radical generation is studied in turn,and the results show that:UV:185 nm,200 w,O₃inlet flow of 20 g/h,p H 8.4,reaction 30 min,total volume 6 L and other conditions unchanged,in the range of 0-10.0000 g/L to change H₂O₂concentration,with the increase of H₂O₂concentration,UV/H₂O₂/O₃system hydroxyl free radical increased first and decreased later.At an H₂O₂concentration of 1.0000g/L,hydroxyl free radicals are generated at27.99 ppm,which is a suitable process condition.UV:185 nm,200 w,O₃inlet flow of 20 g/h,H₂O₂concentration of 1.0000 g/L and reaction volume of 6L were used for washing.Without adding any detergent,the purpose of disinfection and sterilization was achieved at 15 min,and bacteria on the medical dirty cloth were basically killed.Moreover,repeated washing would not change the stretching property of the dirty cloth.As an photochemical oxidation method that produces hydroxyl free radical,the UV/H₂O₂/O₃system achieves the degradation of organic matter and the elimination of bacteria by oxidation and photolysis.It is easy to operate,environmentally friendly and pollution-free,which is very suitable for medical washing.