Preparation And Adsorption Properties Of Uranium On Graphene Oxide Composite Material

Uranium is currently the most major nuclear fuel resource,which produces benefits for the development of economy and nuclear industry.It is necessary to vigorously develop the uranium resources to ensure the celerity and stable development of nuclear power.Extraction of uranium from the seawater will alleviate the shortage of uranium resources and contribute to the development of nuclear energy.The environmental pollution aroused by the discharge of uranium-containing waste solution,which is without treatment pumped into the environment will threaten human health.A variety of uranium adsorption materials have been developed by researchers to solve the problem of uranium shortage and environmental pollution.Graphite oxide,with large specific surface area and oxygen-containing functional groups,which make it easy to be modified by functionalization.At present,it has been widely used in the treatment of uranium-containing radioactive waste liquor and uranium extraction from seawater.In this paper,three kinds of composite adsorption materials with outstanding adsorption capacity and selectivity were prepared by compounding graphite oxide with materials,which are selective to uranium ions.The microstructure and chemical composition of materials were comprehensively characterized by FT-IR,XRD and TEM.The adsorption properties of uranium with different adsorption conditions were investigated.The adsorption behavior of uranium was studied by combining adsorption kinetics models,adsorption isotherm models and adsorption thermodynamic parameters.The uranium adsorption performance and adsorption selectivity of materials in simulated seawater were evaluated,and explored the uranium adsorption mechanism by XPS.rGO-PPy-Fe⁰ composites was synthesized by polymerization at low temperature and liquid reduction methods.The addition of PPy and Fe⁰ will solve the inferior selectivity and adsorption capacity of GO.The optimum p H value of r GO-PPy-Fe⁰ is 8.0,which is closed to the real seawater.The adsorption results indicated that the r GO-PPy-Fe⁰ composites better fitted the Langmuir model and the pseudo-second-order model.It means the uranium adsorbed on r GO-PPy-Fe⁰ is monolayer adsorption process,which dominated by chemical adsorption,and it is a spontaneous endothermia process.The r GO-PPy-Fe⁰ were investigated for the removal of uranium from aqueous solution and simulated seawater.The experimental results demonstrated that the r GO-PPy-Fe⁰ adsorbent possessed a superior capacity for the adsorption of uranium at mg g-1 and ?g g-1 at the pH value of seawater.Based on XPS,we revealed the possible adsorption mechanism of uranium onto r GO-PPy-Fe⁰,which due to the N atom of PPy and Fe⁰ nanoparticles.MIL-88B?Fe?/GO composites were synthesized by hydrothermal method.MIL-88B?Fe?can provide more active sites for the adsorption of uranium?VI?and cover the shortage of limited adsorption sites on GO surface.The p Hopt of MIL-88B?Fe?/GO is 8.0.The kinetic data followed the pseudo-second-order model,indicating a dominant role of chemisorption and the adsorption isotherm were fitted to the Langmuir model.The results showed that the excellent selectivity and cycling performance,which determined that MIL-88B?Fe?/GO adsorbent is a potential material for enrichment of uranium from the seawater.According to the XPS analysis,we propose a possible uptake mechanism that the oxygen and Fe-O are involved in the adsorption process of uranium.The r GO-Fe₃O₄-HA magnetic composite adsorbent were synthesized by coprecipitation method.The abundant carboxyl,hydroxyl,carbonyl and methoxyl functional groups in HA provide a number of active adsorption sites to effectively improve the uranium adsorption capacity of materials.The Fe₃O₄ nanoparticles are conducive to the recovery of adsorption materials.The effects of p H,contact time,temperature and initial uranium concentration on uranium sorption behavior were studied by adsorption experiments.The results showed that the superior adsorption capacity in acidic solution.The adsorption kinetic conforms to the pseudosecond-order model,and the adsorption isotherm is better in accordance with the Langmuir model.r GO-Fe₃O₄-HA performed ultrahigh removal rate of uranium and excellent uranium adsorption capacity in the trace concentration of uranium.The mechanism of uranium adsorption predominately attributed to coordination,which had been confirmed by XPS technique.