Study On The Degradation Performance Of Sulfamethoxazole By Peracetic Acid Activated By New Cobalt Copper Composite Catalyst

Antibiotics,as a emerging contaminants,are widely detected in various environmental media in many countries and regions.As a typical antibiotic of sulfonamides,Sulfamethoxazole（SMX）is one of the antibiotics with the highest detection frequency and detection amount in China.In recent years,the advanced oxidation system of peracetic acid（PAA）,which has a wider p H application range,has gradually attracted the attention of scholars.Transition metals are considered as efficient activators of PAA,and Co is one of the transition metals with the highest activation performance.The residues of toxic metals such as Co²⁺in homogeneous system will cause many adverse effects on human and aquatic organisms.Finding green and environment-friendly catalysts has become one of the challenges in the application of advanced oxidation technology.In order to solve the above problems,two new types of Co,Cu-based composite catalysts,namely spinel cobalt ferrite and copper oxide composite multi-metal oxide Co Fe₂O₄/CuO and Co,Cu bimetallic organic framework Co Cu-MOFs,were prepared in this paper.The effects of different preparation conditions on the performance of the two new types of Co,Cu-based catalysts were investigated,and the best preparation conditions were sought to further explore the performance and mechanism of the two catalysts for activating PAA to remove SMX.The research contents and conclusions are as follows:（1）Nano CuO was prepared by chemical precipitation method,then CuO was added into the sol precursor of Co Fe₂O₄,and the composite material Co Fe₂O₄/CuO was prepared by sol-gel method.At 0.6 g CuO addition and 600℃calcination temperature,the Co Fe₂O₄/CuO/PAA system reached degradation equilibrium in 1.5min and achieved the removal rate of SMX above 92%.In the p H range of 5～9,the removal rate of SMX in the reaction system is still more than 80%.Cl^-and HCO₃^-can produce Cl·and Co₃^2-·in Co Fe₂O₄/CuO/PAA system,thus promoting the removal of SMX.Free radicals quenching experiments show that·OH has a weak effect on SMX removal,and R-O·is the dominant free radical.XPS analysis shows that Co has a significant effect on PAA.（2）Co,Cu-based bi-MOFs（Co Cu-MOFs）was prepared by mixing ZIF-67 and HKUST-1 precursors at room temperature in one step.Co₄Cu₆-MOFs prepared at the Co:Cu ratio of 4:6 had good crystallinity and showed high activation performance for PAA.The removal rate of SMX by Co₄Cu₆-MOFs/PAA system reached 92%in 5 min.In a wide p H range,the reaction system can still maintain a high removal capacity for SMX.HCO₃^-in water can promote the removal of SMX in the early stage of the reaction,and from the final removal rate,it can inhibit the removal of SMX.The presence of Cl^-can also promote the removal of SMX.R-O·is the leading free radical to remove SMX,and Co is the leading element to activate PAA.Co₄Cu₆-MOFs shows good performance after repeated use.