Preparation Of Modified Boron Nitride Composites And Removal Of Sulfamethoxazole From Water

In recent years,the medical industry and animal husbandry have developed more and more rapidly.In order to prevent and treat human and animal diseases,the use of antibiotics will also increase.Because antibiotics are difficult to digest and degrade in the body,the content of antibiotics in water will increase.Among them,sulfamethoxazole（SMX）,as a broad-spectrum antibiotic,is an important member of pollutants.SMX is often detected in wastewater(0.1μg·L^-1–2.5μg·L^-1).Therefore,how to remove antibiotics quickly and efficiently is a hot issue in current research.In this study,carbon-doped boron nitride（CBN）was synthesized by one-step oxygen limiting method to remove SMX from water,and the CBN synthetic materials were systematically analyzed by XRD,SEM,XPS,FT-IR,BET and Zeta potential.The effects of p H value change,different time,different SMX initial concentration and different temperature on the performance of SMX in the adsorption process were studied,and the research on the reusability of the material was evaluated.The experiment shows that the adsorption efficiency is the fastest in the first 10 min,which can basically reach half of the total adsorption capacity.The optimum adsorption capacity can reach 28.75mg·g^-1 at low temperature of 10℃.The reaction conforms to the chemical adsorption of pseudo second-order kinetic model and the monolayer adsorption of Langmuir adsorption isothermal model respectively.According to the study of adsorption thermodynamics,the reaction process belongs to self heat release.After 6 adsorption desorption cycles,the utilization rate of adsorption capacity can reach more than 80%.In order to further improve the adsorption performance of adsorption material,we prepared the calcined layered double hydroxide（CLDH）and CBN composite.CLDH not only has a large specific surface area,but also has the advantage of unique"memory effect".The composite with CBN can not only reduce the agglomeration problem of CLDH,but also increase the specific surface area,increase the adsorption sites and improve the adsorption performance.The CBN/CLDH composites were systematically analyzed by XRD,SEM,XPS,FT-IR,BET and Zeta potential.The effects of different p H value,different time,different initial concentration of SMX and different temperature on the adsorption properties of SMX were studied experimentally,and the reusability of the composites for SMX was evaluated.In the first 30 minutes of the experiment,the adsorption equilibrium can be basically reached,and the maximum saturated adsorption capacity is 45.89 mg·g^-1,which is 60%higher than that of single CBN.The adsorption kinetics conforms to the pseudo second-order kinetic model,indicating chemical adsorption,the adsorption isotherm conforms to the Langmuir adsorption isothermal model,monolayer adsorption,and the study of adsorption thermodynamics shows that the reaction emits heat from itself.After 6 adsorption desorption cycles,the utilization rate of adsorption capacity can still reach more than 75%.