Removal Of Sulfapyridine And Ciprofloxacin From Water By Persulfate Catalyzed By Magnetic Biochar

Sulfonamides and quinolones antibiotics are widely used in the field of human and veterinary,and are difficult to degrade,resulting in a large number of residues in water,causing environmental pollution and serious harm to human health.Therefore,it is urgent to find an efficient and green removal method to degrade antibiotics.In recent years,advanced oxidation processes based on persulfate has been widely concerned by the scientific community because of its efficient degradation ability.Fe has a good activation effect on persulfate,and the surface pore structure of biochar can prevent the agglomeration of Fe particles.Therefore,combining Fe with biochar can prepare a kind of high-efficiency,low-cost and recyclable magnetic biochar material,For the removal of antibiotics.The experimental results are of great significance for the application of magnetic biochar in advanced oxidation process,and provide theoretical and experimental basis for the removal of antibiotics in water environment.Therefore,in this paper,peanut shell was selected as biochar material and modified by ferric salt,and two kinds of iron-based biochar were generated by pyrolysis at 350℃（MBC-650）and650℃（MBC-650）,and their physical and chemical properties were characterized.At the same time,the degradation performance of magnetic biochar MBC-650 on sulfapyridine and ciprofloxacin in water was studied to explore the degradation mechanism.The effects of MBC-650 addition,persulfate concentration,initial p H and coexisting anions on the degradation of antibiotics were compared,and the recycling effect of magnetic biochar was studied to judge the performance and application prospect of the catalyst.The results are as follows:（1）The magnetic biochar prepared at 650℃can be absorbed by the magnet.Scanning electron microscope（SEM）shows that there are dense pores on the surface,and the Fe particles are evenly dispersed on the surface.（2）Compared with sulfapyridine（degradation rate=91.37%）,the degradation of ciprofloxacin by magnetic biochar was stronger（degradation rate=100%）.（3）The initial p H of environment has a great influence on the degradation of antibiotics.sulfapyridine had the best degradation efficiency under neutral acid condition（degradation rate=96.41%）,while ciprofloxacin had the best degradation efficiency under neutral acid condition（degradation rate=94.49%）.In addition,the coexisting anions can inhibit the degradation of sulfapyridine and ciprofloxacin.NO₃^-can inhibit the degradation of sulfapyridine,while Cl^-and SO₄^2-can inhibit the degradation of ciprofloxacin.（4）The degradation rate of magnetic biochar was 48.31%in sulfapyridine system and 29.17%in ciprofloxacin system after 4 times of recycling,so the stability of magnetic biochar in sulfapyridine system was stronger.