Adsorption Of Phosphate And Removal Of Basic Fuchsin Over CeMg-MOF-74

As new kind of organometallic framework material,MOF-74 has unique topological type and unsaturated metal sites and controllable chemical composition and structure and diversified functions.There studies in term of its adsorption,catalytic oxidation,catalytic hydrogenolysis and photo-catalytic of CO₂.Mg-MOF-74 has been paid great attention in the field of adsorption and catalysis due to its high specific surface area and controllable pore size.Metal doping makes the structure of Mg-MOF-74 more complicated,which enhanced its activity and made it more widely used.Phosphorus pollution causes eutrophication,but studies using Mg-MOF-74 treat phosphorous-containing wastewater has not been reported.Based on our research,this paper synthesizes the functional Ce Mg-MOF-74 materials using the solvent synthesis method,with Ce,Mg as the metal active center and 2,5-dihydroxyterephthalic acid as the organic ligand,and carries out analysis of the treatment of phosphorus containing waste water and basic magenta dye waste water.The paper mainly includes the following points:（1）Synthesize different Ce Mg-MOF-74 materials by changing the synthesis conditions such as solvent,molar ratio of raw materials,temperature and time.Then apply this Ce Mg-MOF-74 material to the adsorption of phosphate solution to screen out the materials with excellent performance.The materials were characterized by X-ray powder diffraction,nitrogen adsorption desorption,scanning electron microscopy,X-ray photo-electron spectroscopy and other characterization methods.（2）Apply Ce Mg-MOF-74 materials to adsorb phosphate.Record the effects of initial phosphorus concentration,reaction time and p H of the solution on its phosphorus removal performance.Then analyze the adsorption process using three kinetic models of lagergren pseudo first-order,pseudo second-order and inner particle diffusion,and Langmuir and Freundlich isotherm adsorption models.The results show that the equilibrium adsorption capacity of Ce Mg-MOF-74 for phosphate is 106.4 mg/g,which is40%higher than that of Mg-MOF-74.The adsorption process can be described by the pseudo second-order kinetic equation and is under control of the inner particle diffusion.The boundary diffusion is also of certain effect on the adsorption process.In addition,the adsorption process is consistent with the Langmuir isotherm,and the equilibrium adsorption capacity obtained is 105.3 mg/g,which is very close to the experimental value.（3）Remove photo-catalytic effect of fuchsine dye in solution using Ce Mg-MOF-74 material,investigate the effect of reaction conditions on the removal efficiency,and analyze the process using the pseudo first-order kinetic model.The results show that under the catalysis of Ce Mg-MOF-74,the removal rate of 5 mg/L basic fuchsin solution reached 99%after 2 h under 500 W mercury light.In summary,Ce Mg-MOF-74 has excellent adsorption performance and photo-catalytic activity,and has broad prospect for the application in the field of water treatment.