Performance And Mechanism Of Iron-manganese-copper Composite Hollow Material Activated Persulfate To Degrade Sulfamethoxazole In Water

In recent years,the abuse of antibiotics has led to the widespread presence of sulfonamide antibiotics in natural water bodies,posing potential threats to human health and the ecological environment,which makes the effective removal of antibiotic pollution in wastewater an urgent problem.This paper mainly investigated for CMHS and FCMHS materials with morphology and degradation characteristics,the optimal reaction conditions of the FCMHS+PMS system have been determined through condition optimization experiments.The reaction mechanism of FCMHS activation of PMS and the degradation path of SMX are speculated.The main studies are as follows:Cu-Mn ternary oxide hollow sphere,CMHS was prepared stepwise using carbon spheres as the template,and the Fe-Mn-Cu ternary oxide hollow sphere material,Characterization studies have found that CMHS and FCMHS are hollow material structures with a particle size of about 0.5-1um.Copper and manganese are uniformly supported on the surface of the sphere,and iron is uniformly supported on the surface of copper and manganese.Among them,copper exists in the form of Cu O and a small amount of Cu O₂,manganese exists in the form of Mn O₂,and iron exists in the form of Fe₂O₃.And through a series of condition optimization experiments,it is determined that the reaction system of FCMHS hollow material to activate persulfate to degrade SMX has the best effect.The removal rate of SMX reaches 99%within 60 minutes of reaction time.（1）The effects of different influencing factors on the degradation of SMX in the FCMHS activated PMS system were studied,and it was found that the degradation reaction kinetics of SMX activated by FCMHS activated PMS conformed to the first-order kinetics;with the decrease of SMX concentration,the degradation rate of SMX increased first and then decreased Small;when the dosage of PMS increases,the degradation rate of SMX gradually increases;with the increase of the dosage of FCMHS,the degradation rate of SMX also increases;when the initial p H is weakly alkaline,it is beneficial to the degradation of SMX;neutral The buffer system conditions are conducive to the degradation of SMX,and can stabilize the p H of the system;and PO₄^3-,CO₃^2-,and NO₃^-ions all have an inhibitory effect on the degradation rate of SMX,and Cl^-ions can promote SMX degradation;N₂ will reduce the degradation of SMX;FCMHS material can reach 76.31%of SMX degradation rate after five cycles,and the amount of homogeneous ion dissolution is small,indicating that FCMHS has good recyclability and is an efficient and stable catalyst for degradation of SMX.（2）Through free radical quenching experiment and calculation and EPR analysis,it can be known that In the FCMHS（0.2g/L）+PMS（0.4mmol/L）system,the free radicals that play a leading role in the degradation of SMX are SO₄^·-、·OH、and some¹O₂ oxidation and a small amount of other active substances.These active groups They can be converted into each other,there by improving the degradation efficiency of SMX.In addition,in the FCMHS ternary system,Fe、Mn and Cu are the main active sites on the surface of the FCMHS catalyst to react with PMS to produce·OH、SO₄^·-and ¹O₂.There is a synergistic effect between each other to accelerate electron transfer.Therefore,FCMHS has a high degree of Catalytic activity.Through LCMS-IT-TOF detection and combined literature analysis,13 kinds of intermediate products are analyzed,and it is speculated that 4 degradation pathways SMX can be attacked by¹O₂、·OH、SO₄^·-to cause a series of oxidation,hydroxylation and deamination reactions,and then proceed Dehydration,ring opening,oxidation,etc.,convert macromolecular organic matter into intermediate products of small molecular organic matter.These intermediate products continue to be converted into CO₂,H₂O,NH₄⁺,etc.under the action of active groups such as ¹O₂,·OH,SO₄^·-,NO₃^-etc.