Synthesis Of Functionalized Zirconium-based Metal Organic Framework/Graphene Oxide Composite Nanomaterial And Their Adsorption Properties For Organic Pollutants In Water

In recent years,the global water environment has been polluted to varying degrees.These pollutions directly or indirectly affect human production and life,making the purification and restoration of water environment a global hot issue.The competitive development of various industries has brought economic progress to China.At the same time,there are also some negative effects,such as substandard discharge of industrial sewage and improper disposal of garbage,which threaten the quality of our water environment.Organic pollutants are difficult to be degraded,harmful and costly to treat.Among them,dyestuffs and antibiotics are two kinds of organic pollutants,which are difficult to deal with.Once such pollutants enter the water,they will cause serious harm to our health after a long time of migration,transformation and accumulation.Therefore,it is urgent to deal with organic pollutants.In this paper,we first prepared functional zirconium metal-organic framework and graphene oxide composite nanomaterials.Scanning electron microscopy（SEM）,X-ray powder diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）and X-ray photoelectron spectroscopy（XPS）were used to characterize the samples.It laid a theoretical foundation for the following studies on the adsorption of methylene blue（MB）and tetracycline hydrochloride（TC）by Ui O-66-（OH）₂/GO.At the same time,the influence of various experimental factors（solution p H,reaction temperature,pollutant concentration,reaction time,etc.）on the ability of adsorbent materials to absorb MB was studied.Through the corresponding experimental data,the isothermal adsorption model,kinetic model,thermodynamics and other mathematical models of the adsorption process were fitted.The experimental results showed that the modification of hydroxyl and the addition of GO increased the adsorption capacity of the original Ui O-66.The removal of MB from Ui O-66-（OH）₂/GO can be improved by a slightly alkaline solution environment and an increase in temperature.However,the acidity and alkalinity of the solution had little effect on the adsorption of TC of Ui O-66-（OH）₂/GO.According to the analysis of isothermal adsorption curve model,kinetic model and thermodynamic model,the fitting of the isothermal adsorption model of Ui O-66-（OH）₂/GO for MB was more in line with the Freundlich and Sips,the fitting of the isothermal adsorption model of Ui O-66-（OH）₂/GO for TC was more in line with the Freundlich.The adsorption process of Ui O-66-（OH）₂/GO for MB and TC were more consistent with the Pseudo-second-order kinetic model.Those showed that the adsorption of MB and TC by Ui O-66-（OH）₂/GO were monolayer,the adsorption surface was heterogeneous and dominated by chemical adsorption.The results of thermodynamic analysis showed the adsorption process was spontaneous and the solid/liquid interface was disordered.The addition of the anions in the solution was inhibit the adsorption of MB by the composite material:The higher the concentration,the greater the influence on the adsorption of MB,The greater the anion charge,the greater the effect.In addition,repeatability experiments explored the reusability of the Ui O-66-（OH）₂/GO composite material,and found that after three cycles of adsorption,the MB removal efficiency of the composite material remained at a relatively high level.It was suggested that Ui O-66-（OH）₂/GO composites could reuse.On the one hand,it can reduce the dosage of absorbents.On the other hand,it can also reduce the secondary pollution of composite materials to the environment.The analysis in this paper showed that the Functionalized Zirconium-based Metal Organic Framework and GO composite nanomaterials have good stability and good removal ability to MB and TC.It is a kind of adsorbent with relatively promising application prospects,which can provide some guidance for the study of composite adsorbents.