Degradation Of Sulfadiazine In Simulated Wastewater By Electro-activated Persulfate Oxidation

Sulfadiazine(SD)is an antibiotic with high stability and strong hydrophilicity.It is widely used in the treatment of upper respiratory tract infections,intestinal infections and other diseases.However,after a large number of sulfadiazine antibiotics are used,the drugs are discharged into the environment in the form of human and animal excreta.They have high drug resistance and ecological toxicity in the environment,posing a serious threat to human health and ecology,and causing people’s health.Great attention.a large number of Sulfadiazine are released into the environment in the form of human and animal excrement and unused waste.These residues are highly resistant and ecotoxic in the environment,it will pose a serious threat to human health and ecology,which has aroused great concern.For this reason,this paper explored the electro-activated peroxymonosulfate(PMS)method to degrade sulfadiazine simulated wastewater.PMS oxidant is a new type of chemical oxidant used to degrade organic pollutants.It can be activated by transition metal ions,heat,ultraviolet light and other methods to produce highly oxidizing sulfate radicals and hydroxyl radicals.However,these catalytic methods have the disadvantages of large dosage of oxidant,difficult to recycle the catalyst,and easy to cause secondary pollution.Electrochemical oxidation technology is also a widely used method for degradation of organics in water in recent years,but the effect of graphite electrodes in degrading organics is poor.BDD electrodes are expensive and have a short service life.Therefore,this paper uses a combination of electrochemical oxidation and PMS oxidation to degrade sulfadiazine wastewater.This paper connected the external power supply to the graphite plate inserted into the simulated wastewater to form a closed loop,and constructs a DC power supply system and a pulse power supply system respectively.First,compare the degradation of sulfadiazine by a single electrochemical oxidation system,a single PMS oxidation system,a direct current activated PMS system,and a pulsed electroactivated PMS system to verify the effectiveness of electro-activated PMS to degrade sulfadiazine.Electrochemical workstation was used to characterize the electrode to prove the main mechanism of electro-activated PMS degradation of sulfadiazine;Using ESR technology to detect the main active substances,and verify the reason why the pulse electric activated PMS system produces better results than the direct current activated PMS system.The effects of pH value,voltage,PMS dosage,and plate spacing on the degradation of sulfadiazine in electro-activated PMS system were explored.Secondly,the effects of pulse frequency and anions on the degradation of sulfadiazine in the pulsed electro-activated PMS system were further explored;The response surface(RSM)model optimization was constructed.Under the optimized process parameters,the predicted value of the sulfadiazine degradation rate is similar to the experimental value,which proves that the pulse electro-activated PMS system is an efficient sulfadiazine degradation method;And use GC-MS to identify the intermediate products in the degradation process and infer the degradation path.When the voltage is 6 V,the pH value is 7,the ratio of PMS and SD is 1:1,the distance between the plates is 3 cm,and the pulse frequency is 2000 HZ,the degradation efficiency of the pulse electro-activated PMS system for sulfadiazine can reach 80.12%.