Study On The Adsorption Performance Of Fe₃O₄ Functionalized Nanocomposites For Thorium

As a kind of clean energy,nuclear energy does not release a large amount of greenhouse gases during large-scale development,and has a certain protective effect on the environment.It has gradually attracted attention from all fields of the world.However,the rapid development of nuclear technology and the waste generated by the mixed metal samples used in these areas pose a serious threat to the environment and human health.Compared with uranium,the main energy source for nuclear energy,thorium resources are more abundant.In recent years,thorium-based fast reactors have been developed in a large amount.However,at the same time as the development,a small amount of thorium is inevitably released into industrial wastewater.In this case,it has caused great harm to the environment and organisms.Therefore,finding an efficient and fast way to enrich thorium is of far-reaching significance for protecting the environment and promoting human development.In recent years,ferroferric oxide has become a research hotspot at home and abroad due to its excellent paramagnetism,better adsorption performance,low toxicity and easy functionalization.However,exposed ferroferric oxide is very easy to aggregate and is easily oxidized.Fortunately,this problem can be effectively solved by modifying its surface with functional materials with excellent properties.Therefore,this thesis uses ferroferric oxide as the substrate,prepares it into hollow microspheres,and decorates the surface with silica,manganese dioxide,cysteine,and molybdenum disulfide,respectively,and prepares Fe₃O₄@SiO₂@MnO₂ and Fe₃O₄@Cy@MoS₂ two ferroferric oxide functionalized nanocomposites were used to remove low-concentration thorium,and the single-factor method was used to explore their effects on thorium adsorption under different experimental conditions.The specific research methods and conclusions are as follows:1)In this study,the magnetic nanocomposite Fe₃O₄@SiO₂@MnO₂ was synthesized by chemical precipitation method,and its effect on the removal of thorium in wastewater was studied.Batch adsorption experiments show that Fe₃O₄@SiO₂@MnO₂ has an ideal adsorption effect on thorium in wastewater.The optimal optimized conditions for this experiment are as follows:p H=3.5,reaction time of 60 minutes,adsorbent dose(solid-liquid ratio)of 0.40g L^-1,and the optimal initial concentration of thorium is 20 mg L^-1.The adsorption kinetics follows the pseudo-secondary model(R²=0.9897).By fitting the experimental data with the Langmuir model(R²=0.9988),it can be concluded that the maximum adsorption capacity of Fe₃O₄@SiO₂@MnO₂for thorium is53.19mg g^-1.At the same time,the thermodynamic parameters also indicate that the reaction process is a spontaneous endothermic reaction.In short,we have successfully prepared Fe₃O₄@SiO₂@MnO₂magnetic nanomaterials and have taken an important step in its removal of the radionuclide thorium.2)A three-dimensional flower-like Fe₃O₄@Cy@MoS₂ composite material was prepared by modifying L-cysteine on the surface of magnetic ferroferric oxide and further modifying molybdenum disulfide on the surface of Fe₃O₄@Cy by hydrothermal method.Use it as an effective adsorbent for thorium.At the same time,the effects of p H,solid-liquid ratio,initial concentration,temperature,and time on the adsorption performance of the experiment were studied through batch adsorption experiments.The experimental results show that the material has a good adsorption effect on thorium when the p H is 3.5,the solid-liquid ratio is0.5g L^-1,and the initial concentration is 30mg L^-1.The maximum adsorption capacity is 62.11mg g^-1.In this thesis,Fe₃O₄ was used as the substrate and modified with different functional materials with excellent properties to prepare two new functional composite materials(Fe₃O₄@SiO₂@MnO₂ and Fe₃O₄@Cy@MoS₂)to enrich the highly toxic radionuclide thorium in wastewater was discussed with its maximum adsorption capacity under optimal reaction conditions,and good results were obtained,providing experimental and theoretical basis for the removal and treatment of thorium wastewater.