Preparation Of Cobalt-based Catalyst And Activation Of Peroxymonosulfate (PMS) To Degrade Tetracycline Hydrochloride In Water

In recent years,the continuous discharge of antibiotic wastewater into water has greatly affected the ecosystem.Advanced oxidation of persulfate is a common method to degrade organic matter.Compared with the free radical led persulfate advanced oxidation technology,the non-free radical led persulfate advanced oxidation technology can produce mild non-free radical oxidant,has higher selectivity to the oxidation of organic pollutants,is less affected by other substances in the water,and can avoid the excessive use of persulfate.The advanced oxidation technology of persulfate dominated by non-free radicals has been widely studied and gradually become a new method to degrade organic pollutants.Singlet oxygen（¹O₂）,as an active oxygen produced by non-free radical oxidation pathway,has been widely concerned by researchers because of its relatively mild oxidation potential and moderate half-life.Lattice oxygen（O_L）and oxygen vacancy（O_V）play important roles in the formation of ¹O₂.In this paper,cobalt-based catalyst was taken as the research object,and a cobalt-based bimetallic oxide catalyst rich in O_L and O_V was prepared by regulating the chemical composition of the catalyst to degrade tetracycline hydrochloride（TCH）by acting on permonosulfate（PMS）,so as to explore the catalytic activity and reaction mechanism of the catalyst in the process of activating PMS to degrade TCH.The main research results are as follows:（1）Co₃O₄/α-Mn₂O₃ catalyst catalyzed the degradation of TCH reaction system by PMS.Co₃O₄/α-Mn₂O₃ catalyst was synthesized by hydrothermal and calcination process synthesis.The catalyst was characterized by XRD,SEM,BET and XPS,and the physicochemical properties of the catalyst were analyzed.It was proved that Co₃O₄/α-Mn₂O₃ is rich in O_L and O_V,and has excellent PMS activation ability.At the same time,through the study of the amount of PMS,the amount of catalyst,TCH concentration,initial p H and other key parameters,to determine the best use conditions of the catalyst.At room temperature（25℃）,20 mg catalyst and 15 mg PMS can degrade 50 m L 20 mg/L TCH by 82%in 40 minutes.The stability of the catalyst is good,and it is not affected by the common inorganic anions in water,indicating that the catalyst has good practicability.The mechanism analysis of oxidation TCH in Co₃O₄/α-Mn₂O₃/PMS system shows that ¹O₂ is the main active oxygen species.Finally,the degradation path of TCH by Co₃O₄/α-Mn₂O₃ catalyst activated by PMS was analyzed by liquid-mass test.（2）Cu Co₂O₄/CN catalyst catalyzed the degradation of TCH reaction system by PMS.Cu Co₂O₄/CN catalyst was prepared by roasting the Cu-Co oxalic acid precipitating precursor with melamine and used as catalyst to activate PMS and degrade TCH.The catalyst was characterized by XRD,SEM,BET and XPS,and the physicochemical properties of the catalyst were analyzed.Compared with Cu Co₂O₄ and Cu Co₂O₄/g-C₃N₄,Cu Co₂O₄/CN was rich in oxygen vacancy and showed higher catalytic activity.At the same time,through the study of the amount of PMS,the amount of catalyst,TCH concentration,initial p H and other key parameters,to determine the best use conditions of the catalyst.At room temperature（25℃）,a20 mg catalyst and 10 mg PMS can degrade 50 m L of 20 mg/L TCH by 97%in 5 minutes.The catalyst has good stability and is less affected by common inorganic anions in water,which indicates that the catalyst has good practicability.Combined with the literature,the oxidation mechanism of TCH in Cu Co₂O₄/CN/PMS system was analyzed.The results showed that Co²⁺and O_V were the key to the production of reactive oxygen species,and ¹O₂ was the main active oxygen species.Finally,the degradation path of TCH activated by Cu Co₂O₄/CN catalyst was analyzed by LCMS.