Synergistic Degradation Of Oxytetracycline By Fenton-like Reaction And Perovskite Photocatalyst

Antibiotics,as a new environmental hazard,have attracted wide attention.It is urgent to find an efficient and environmentally friendly method to remove antibiotic pollutants from water.Compared with the traditional Fenton method,the advanced oxidation technology based on·SO₄^-has broad application in degrading antibiotic pollutants due to its strong oxidizing ability,wide pH range（pH=2-9）,high efficiency,easy storage and transportation.·SO₄^-can be produced from persulfate activated by light,heat or transition metal ions.This thesis aims to promote the production of·SO₄^-and degrade antibiotics more efficiently.Oxytetracycline was chosen as the degradation target due to its high detection rate and detection amount in natural water.The main research contents and results are described as follows.（1）The degradation behavior of oxytetracycline by potassium bisulfate（PMS）was investigated.The effects of temperatures,amount of PMS and pH values on the degradation behavior of oxytetracycline in PMS system together with the reaction kinetics was discussed.The results showed that increasing PMS amount,increasing temperature and decreasing pH were beneficial to the degradation of antibiotics.Compared with Fe²⁺,Co²⁺was more effective in activating PMS to produce·SO₄^-to degrade oxytetracycline.After 40 min of reaction,the degradation rate was up to69.7%.（2）The photocatalytic degradation of oxytetracycline by Co/BiFeO₃/PMS was studyed.The xCo-BFO composite powders with different Co content were prepared by hydrothermal method and characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）and ultraviolet-visible diffuse reflectance spectroscopy（UV-vis DRS）.The degradation of oxytetracycline by Co/BiFeO₃ under the synergistic action of photocatalysis and Fenton-like oxidation was investigated.The results showed that the degradation efficiency of oxytetracycline increased with the increase of Co doping.Increasing PMS concentration,increasing temperature and decreasing pH were also beneficial to the degradation of oxytetracycline.After 40minutes of reaction,the degradation efficiency of oxytetracycline reached 96.9%.（3）The photocatalytic degradation of oxytetracycline by CoTiO₃/PMS was researched.CoTiO₃ nanoparticles were successfully synthesized by sol-gel method,and characterized by XRD,SEM and UV-vis DRS,respectively.By comparing the degradation effects of PMS,CoTiO₃ and CoTiO₃/PMS on oxytetracycline,it was found that CoTiO₃/PMS system could degrade oxytetracycline efficiently.The degradation rate of oxytetracycline was up to 99.6%after 40 min of illumination,showing obvious synergistic effect of Fenton-like oxidation and photocatalysis.The effects of CoTiO₃ concentration,PMS amount,reaction temperature and initial pH value of the system on the reaction rate were further investigated.