| Sufficient supply of natural uranium resource is one of the guarantees for the steady development of nuclear power.However,in the development process of natural uranium,such as mining,hydrometallurgy,transformation and reprocessing,a large amount of uranium-containing radioactive water not only seriously waste of natural uranium resources,but also causes severe environmental problems.For the heavy metal toxicity and radiotoxicity of uranium,how to efficiently remove,separate and enrich uranium in radioactive waste water is one of the difficulties in environmental radiochemistry.The adsorption method has attracted widespread attention for its advantages such as easy implementation,low cost,and high efficiency.The design and preparation of highly effective adsorbents is extremely important.The magnetic inorganic-organic Zr（IV）phosphonate hybrid material presents the stability of inorganic material,abundant organic functional groups with strong affinity to uranium on the surface,and it is easy to be separated from the solution quickly.Therefore,it is of great research and practical significance to use magnetic inorganic-organic zirconium phosphonate hybrid material for uranium removal and recovery.In this paper,inorganic-organic zirconium phosphonic acid hybrid material was prepared by hydrothermal reaction with organic phosphonic acid and inorganic zirconium source Zr OCl2·8H2O.The physical and chemical properties of the material were characterized by SEM&EDS,FT-IR,XRD,Zeta potential,XPS,TGA,contact angle and VSM analysis.The effects of factors such as p H value,contact time,initial concentration and temperature on U（Ⅳ）adsorption performance of the material were studied.The adsorption kinetics,isotherm and thermodynamics were discussed,and the selectivity,desorption characteristics and reusability of U（Ⅳ）were studied.First part,diethylenetriamine pentamethylene phosphonic acid（DTPMP）was selected as the organic phosphine source to synthesize hybrid（Zr-DTPMP-x,where x is the atomic molar ratio of phosphine to zirconium）as the adsorption.The effect of the molar ratio of phosphine to zirconium on the adsorption performance of Zr-DTPMP-x for U（Ⅳ）was explored.The results showed that the optimal phosphine-zirconium ratio,p H,equilibrium time,and dosage was 2:1,4.0,180 min,and 10 mg.The saturated adsorption capacity of Zr-DTPMP-x to U（Ⅳ）adsorption monolayer 182.72 mg·g-1.Then,on the basis of determining the optimal phosphine zirconium ratio of 2:1,the effects of phosphine sources on the U（Ⅳ）adsorption performance of inorganic organic zirconium phosphonate hybrid materials（Zr P-y,where y is a different phosphine source）were studied.DTPMP,ethylenediaminetetramethylene phosphonic acid（EDTMP）,2-phosphonic acid butane-1,2,4-tricarboxylic acid（PBTC）,creatine phosphate tetrahydrate（COP）,phosphonic acid muscle Alcohol（CP）was used,and five kind of hybrid materials have been synthesized.The results showed that the adsorption capacities of Zr-DTPMP,Zr-EDTMP,Zr-PBTC,Zr-CP,and Zr-COP for U（Ⅳ）were 182.72 mg·g-1,227.51 mg·g-1,162.54 mg·g-1,205.79 mg·g-1,and 209.06 mg·g-1,respectively.At the same time,the selectivity of Z-EDTMP for U（Ⅳ）was superior to that of the other four hybrid materials,so EDTMP is selected as the optimal phosphine source for U（Ⅳ）adsorption and used in subsequent experiments.Finally,EDTMP was selected as the phosphine source on the basis of the above research,and the optimal phosphine zirconium ratio was 2.A magnetic hybrid material（MZr P-m-T,where m and T are the available dosage and the synthetic Celsius temperature respectively）was prepared by using carbon-coated Fe3O4（Fe3O4@C）as the magnetic component.The effects of Fe3O4@C doping amount and synthesis temperature on the U（Ⅳ）adsorption performance of MZr P-m-T were studied.The results showed that when the dosage of Fe3O4@C was 4%and the synthesis temperature was 100℃,the magnetic hybrid material had the best adsorption performance for U（Ⅳ）,the equilibrium adsorption capacity was 245.10 mg·g-1,and the equilibrium time was 360 min.The above results indicate that the ratio of phosphine to zirconium and the source of phosphine inextremely affect the adsorption performance of hybrid materials for removal of U（Ⅳ）.Magnetic inorganic-organic zirconium phosphonate hybrid material shows excellent adsorption performance for U（Ⅳ）,which is expected to provide a new material and a new method to resolve the problem of efficiently removing,separating and enriching uranium in radioactive waste water. |
