| The excessive use and improper treatment of pharmaceuticals and personal care products(PPCPs)have not only led to serious pollution to the water environment,but also caused huge health risks to human.So,PPCPs have become a new type of organic pollutants that need to be solved urgently.Metal-organic framework materials(MOFs)have great advantages in removing many pollutants in water because of their adjustable structure and superior specific surface area.However,their microporous structure and poor hydrothermally stability make it difficult to realize efficient adsorption performance of macromolecular pollutants.Therefore,this study focuses on the cephalosporin antibiotics and is devoted to preparing MOF-derived mesoporous carbon materials with excellent pore structure and stability so as to improve the adsorption performance of macromolecular antibiotics in water environment.The main contents and results are as follows:1.Zn-MOF precursors were prepared by solvothermal method,the adjustment effect of Sodium Dodecylbenzene Sulfonate,N-Cetyldimethylamine and Stearyltrimethyl Ammonium Bromide on the pore size of MC-X carbon materials was explored.Characterization results such as SEM,XRD and FTIR showed that the templates could not only effectively improve the pore sizes and functional groups of the carbon materials,but also did not damage the good morphology and crystalline structure of the Zn-MOF precursors.The experimental results of different materials on ceftazidime indicated that the optimum template was N-Cetyldimethylamine(CTA),and when the value of CTA/Zn2+ was 0.3,the adsorption capacity of MC-0.3 material for ceftazidime was as high as 371.18 mg·g-1.The pore size of MC-0.3 material is 3.94 nm,and the ratio of the mesopore volume to the total pore volume is 97.71%.2.The adsorption performance of MC-0.3 material for ceftazidime at different adsorption temperature,ionic strength,initial concentration,initial pH value,and natural organic matter was studied.The adsorption conditions of ceftazidime on MC-0.3 material were ascertained through the response surface model:at the temperature of 25.83℃,the initial pH value of 4.49,and the ionic strength of 0.71 g·L-1,the simulated optimum adsorption capacity was 471.43 mg·g-1.Besides,MC-0.3 material could maintain more than 90%of the adsorption capacity after five times of adsorption and regeneration,showing good stability and regeneration performance.3.The adsorption mechanisms of ceftazidime on MC-0.3 material were studied.The results suggested that the adsorption of MC-0.3 material for ceftazidime could be described by the mixed 1,2-order(MOE)model.The adsorption isotherm satisfied the Freundlich model.And the adsorption of ceftazidime on MC-0.3 was a spontaneous,multilayer and endothermic process.The matched pore size effect,hydrogen bonding and hydrophobic interactions were the main mechanisms for the adsorption of ceftazidime on MC-0.3 material.4.The adsorption experiments of cephalosporin antibiotics on the MC-0.3 material and the analysis results of the QSPR model indicated that the MC-0.3 material showed a higher adsorption capacity for eight antibiotics.The H-donors and polar surface area of cephalosporin antibiotics can affect the adsorption performance.The MC-0.3 carbon material prepared by the template method in this study had a mesoporous structure,excellent stability and efficient adsorption performance.The template method is expected to apply microporous materials to the removal of macromolecular emerging pollutants in water. |
