Preparation Of Iron Matrix Composites And Study On Performancefor The Removal Of Uranium

In this research,iron is used as the matrix material,other materials are loaded to functionalize it.Three composite materials have been successfully synthesized.These three materials have good removal effect on U?VI?ions in sewage,which are easy to separate,low cost,reusable,high adsorption capacity,etc.It is a new type of research material.The TEM,XPS,XRD,Raman,FTIR and other three characterizations of the three materials are characterized by their morphology,structure,elements,etc.The effects of different initial uranium concentration,pH value,temperature during reaction,contact time of adsorbate and adsorbent on removal of U?VI?were studied,and removal mechanism of U?VI?ions were analyzed?1?Preparation of EDTA-mGO composites and its adsorption of U?VI?in solution:Successfully synthesize graphene oxide?GO?using modified Hummer method,and then combine Fe₃O₄ with GO to prepare magnetic graphite oxide?mGO?.The EDTA-mGO composites were prepared by combining EDTA and mGO,and then characterized by SEM,XRD,FTIR,etc.,and then the EDTA-mGO composites were applied to the adsorption of U?VI?in wastewater.The adsorption of U?VI?showed that the adsorption of U?VI?by EDTA-mGO accorded with pseudo-second-order kinetics and Langmuir model.The adsorption capacity was 277.43 mg/g at 298 K,and the calculated values of the thermodynamic parameters show that the adsorption of U?VI?by EDTA-mGO is a spontaneous endothermic process.?2?Preparation of nano-zero-valent iron/chitosan?NZVI/CS?and its removal of U?VI?:complexing zero-valent iron with chitosan and successfully preparing nano-zero-valent iron/Chitosan?NZVI/CS?composites by reduction method,and then a series of characterizations such as HRTEM,Raman,Zeta potential,etc.to analyze its morphology,surface adsorption sites and surface charges,etc.,the removal effect of nano-NZVI/CS on U?VI?was studied by bulk adsorption experiments,the experimental results show that the data can be better described by the pseudo-second-order kinetics and the Langmuir model,and according to the calculation,the adsorption capacity of U?VI?at the temperature of 298 K is 591.72mg/g.According to the thermodynamic parameters,it is known that the removal of U?VI?by nano-NZVI/CS is an exothermic process.According to the research on its adsorption mechanism,the removal of U?VI?by nano-NZVI/CS has not only the adsorption of chitosan but also the reduction of zero-valent iron.?3?Preparation of iron-nickel/graphene oxide?Fe-Ni/GO?composites and their U?VI?removal behavior in wastewater:The iron-nickel/graphene oxide?Fe-Ni/GO?composites were successfully prepared by the hydrothermal synthesis method by combining Fe and Ni bimetals with GO.The prepared composites were characterized by SEM,TG and XPS to analyze their morphology,thermal stability and element composition.Fe-Ni/GO composites were applied to the removal of U?VI?in wastewater.After comparison of experimental results,the removal of U?VI?by Fe-Ni/GO was more consistent with the pseudo-second-order kinetics and Langmuir model.The equilibrium state of adsorption has been reached within 25 min,and the removal capacity of U?VI?at 298 K is calculated to be 384.62 mg/g.The thermodynamic parameters indicate that the removal of U?VI?by Fe-Ni/GO is an endothermic process.The adsorption mechanism was studied by FTIR,XPS and EDS Mapping,the results show that the removal of U?VI?by Fe-Ni/GO composites not only showed the adsorption of U?VI?by GO,but also showed the reduction effect of Fe-Ni on U?VI?,which increased the removal amount of U?VI?.