Preparation Of Co-Composite Nanomaterials And Study On Its Catalytic Oxone For The Degradation Performance For Levofloxacin Hydrochloride

Advanced oxidation processes?AOPs?are the technology of degrading organic pollutants which are difficult to be biodegraded by free radicals such as hydroxyl radical?·OH?,sulfate radical(SO₄^·-)and superoxide radical(O₂^·-).Compared with·OH,the oxidation of SO₄^·-is stronger,the half-life is longer and the pH range is wider.SO₄^·-is generally produced by Oxone,which is catalyzed by the metal ions,metal oxides,light and heat.The high catalytic activity of Co makes Co?II?/Oxone one of the most common oxidation systems.However,the soluble Co?II?is not easily recovered after the end of the reaction,and can cause secondary pollution to the environment as the discharged wastewater flows into the water body,so the synthesis research of the insoluble cobalt-containing nano material is more and more common.Waste battery is a kind of pollutant which is harmful to environment and human health at the same time it also contains rich metal resources.However it is rare to reuse waste battery as a resource.The main purpose of this experiment is to prepare magnetic nano-materials by using waste batteries as raw materials containing Co and Fe.Different materials were used to synthesize the insoluble cobalt-containing composite nano-catalyst to catalyze Oxone to generate SO₄^·-,and the new oxidation system composed of the catalyst and the Oxone was used to degrade levofloxacin hydrochloride?LVF?to find the best operating conditions.At the same time,the preparation of other cobalt composites and the degradation of LVF with Oxone component oxidation system were also studied.The main contents and conclusions of this paper are as follows:?1?Preparation of CoFeO₂@CN nanomaterials and study of the degradation of LVF by CoFeO₂@CN/Oxone oxidation system.The used waste lithium battery was disassembled,dissolved and filtered to obtain the solution containing Co²⁺.According to the r equirement of Co²⁺and Fe³⁺content ratio,a certain amount of Fe³⁺was added.And then the CoFeO₂ catalyst was synthesized by hydrothermal synthesis.After calcination and carbonization,CoFeO₂ was loaded onto nitrogen carbide to obtain CoFeO₂@CN.By the means of scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray photoelectron spectroscopy?XPS?and Magnetic test?VEM?analyzed the microstructure,chemical structure,composition elements and magnetic properties of the materials And then the catalytic activity of CoFeO₂@CN was studied by the catalytic effect of Oxone on the degradation of LVF.13%CoFeO₂@CN catalyzes the degradation of LVF by Oxone is very good.When the initial concentration of LVF is 10 mg/L,the dosage of catalyst is 15 mg,the concentration of Oxone is 0.5 mmol/L,the reaction temperature is 25?±5?,and the initial pH is 7.0,the degradation of LVF in 40 min is up to 89.4%.After the catalyst was recycled for 5 times,the degradation of LVF was still more than 70%.The results show that the composite has good recyclability and repeatability.?2?Preparation of CoS₂@g-C₃N₄ nanomaterials and study of the degradation of LVF by CoS₂@g-C₃N₄/Oxone oxidation system.Firstly,g-C₃N₄ was obtained by calcining dicyandiamide and ball milling,and then CoS₂@g-C₃N₄ nano-material was prepared by adding g-C₃N₄ into hydrothermal reaction.The characteristics of the prepared material was analyzed by means of SEM,TEM and XPS,and then the catalytic activity of the materials was studied by the degradation effect of LVF.The optimum degradation conditions of CoS₂@g-C₃N₄/Oxone system is:the dosage of catalyst is 10 mg,the Oxone is 0.3 mmol/L,the temperature of 20?±2?and the initial pH is 3.5,the degradation of LVF in 25min is up to 99.9%.At the end of the reaction,the material was recovered,centrifugal and drying,then recycling experiment test was carried out.After three times of repetition,the LVF removal effect was still good,which indicated that the material had good repeatability.?3?Preparation of CoS₂@Bi₂WO₆ nanomaterials and study of the degradation of LVF by CoS₂@Bi₂WO₆/Oxone oxidation system.Firstly,CoS₂@Bi₂WO₆ was synthesized by different synthetic steps,and then the CoS₂@Bi₂WO₆ by one-step synthesis is the best catalytic with the simple degradation experiment.The characteristics of the CoS₂@Bi₂WO₆ was analyzed by means of SEM,TEM and XPS,and then the catalytic activity of the materials was studied by the degradation effect of LVF.The optimum conditions of the CoS₂@Bi₂WO₆/Oxone system were obtained by optimizing the factors:the dosage of catalyst is 15 mg,the Oxone is 0.1 mmol/L,the temperature of 20?±2?and the initial pH is 3.5,the degradation of LVF in25 min is up to 99.9%.The results of free radical capture test showed that the system was degraded LVF by hydroxyl radical and sulfate radical.