The Adsorption Behaviors Of Poly(cyclotriphosphazene-co-4,4-sulfonyldiphenol) On Thorium(?) And Uranium(?)

The poly(cyclotriphosphazene-co-4,4-sulfonyldiphenol)(PZS)microspheres were made by one step precipitation copolymerization with4,4'-sulfonyldiphenol(BPS)and hexachlorotriphosphazene(HCCP).The preparation method was simple and the condition was mild.PZS contain a large number of N,P and O atoms with negative electron couds and their particles have a highly crosslinked structure.And due to its special organic-inorganic hybrid molecular structure,it also has the chemical stability of inorganic polymeric materials,thermal stability,and molecular structure and adjustableproperties of organic polymeric materials and other advantages.Therefore,these characteristics make PZS have been applied in many aspects.The researchers have explored the use of ring-crosslinked polyphosphazene materials for emulsifying properties,catalyst supports,dye sorbents and fluorescent chemical sensors.However,there have few reports on the treatment of radioactive element in wastewater by PZS.The experiment explored the use of ring-crosslinked polyphosphazene microparticles to adsorb thorium(IV)and uranium(VI)in nuclear industrial wastewater,and expected better results.In this paper,PZS materials were synthesized by a one-step precipitation copolymerization method,and then used to study the adsorption properties of thorium and uranium in aqueous solution.The paper mainly includes the following aspects:1.A series of overviews of the treatment methods for radioactive waste water were presented.At the same time,the application of PZS was briefly described.Finally,the main research contents of the paper were proposed.2.poly(cyclotriphosphazene-co-4,4-sulfonyldiphenol)(PZS)particles prepared by a one-stepprecipitationmethodusing4,4'-sulfonyldiphenol(BPS)and hexachlorotriphosphazene(HCCP).PZS was characterized by FTIR and X-ray photoelectron spectroscopy(XPS)to confirm the successfulsynthesis of the material.The external appearance of PZS was analyzed by scanning electron microscope(SEM).3.This paper systematically studied the effects of pH,shaking time and initial concentration,interfering ions on the behavior of PZS adsorbing thorium and uranium.The experimental resultsshowed that the input of PZS was 10 mg,pH was 3.5,and the initial concentration of thorium was 25mg/L,the adsorption amount was 17.30 mg/g.By kinetic studies,the adsorption process of PZS on thorium in accordance with pseudo-second order kinetics.By comparing Freundlich(R~2=0.9569)and Langmuir(R~2=0.9783),the adsorption behavior is more consistent with Langmuir;thermodynamic studies showed that the adsorption of PZS on thorium was a endothermic and hot spontaneous process.In addition,the interference ions have almost no effect on thorium adsorption.When pH of solution was 4.0,and the initial concentration of thorium was 30mg/L,the adsorption equilibrium is reached after shaking at 25?for 90 min,and the adsorption amount is 19.75mg/g.The adsorption process of uranium by PZS accords with the pseudo-second order kinetics,and the adsorpion behavior is more consistent with that of Langmuir.Thermodynamic studies showed that the adsorption of uranium by PZS was an endothermic and spontaneous process.And PZS have good selectivity for uranium adsorption.