Preparation Of The Mono/bi-amidoxime-based Open-chain Polyether Fungus Modified Materials And Their Adsorption Of Uranyl Ions

With the development of nuclear energy,mankind’s demand for uranium resources is increasing.Uranium mining and other processes will produce a large amount of uranium-containing wastewater,causing environmental pollution.Uranium is extremely radioactive and chemically toxic,and can cause serious harm to the human body.Therefore,the treatment of uranium-containing wastewater has become an important problem that needs to be solved urgently.In this study,some synthetic methods of condensation,substitution,and amidoxime reaction were used to prepare the mono/bi-amidoxime-based open-chain polyether fungus modified materials,and the materials before and after modification and adsorption were characterized by Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TGA）,scanning electron microscopy（SEM）and Brunauer-Emmett-Teller analysis（BET）.The single factor method was used to preliminarily investigate uranium（VI）adsorption capacity of aim material influenced by some factors.On this basis,the orthogonal experiment was applied to further obtain the optimal adsorption condition and the maximum adsorption capacity.In this experiment,repeated experiments and anti-interference experiments were carried out on the materials to explore the possibility of its practical application,and used the adsorption kinetic model and isothermal adsorption model to preliminarily explore the adsorption mechanism of the adsorbent.The main conclusions are as follows:（1）In this experiment,the mono/bi-amidoxime-based open-chain polyether fungus modified materials were synthesized and characterized.SEM and BET results showed that the surface of the target materials had become rougher after modification.The specific surface area had increased from 14.8768 cm²g^-1before modification to 17.6306 cm²g^-1（single-finger material）and 22.9869 cm²g^-1（dual-finger material）after modification.This was beneficial to increase the adsorption capacity.TG results showed that the two modified materials had better thermal stability.（2）The adsorption experiment showed that the optimal adsorption conditions of the two target materials were the same(initial U（VI）concentration:40 mg L^-1,solid-liquid ratio:25 mg L^-1,initial p H value:6.0,contact time:130 min)and the maximum adsorption capacity were295.48 mg g^-1（single-finger material）and 446.20 mg g^-1（dual-finger material）.The results of repeatability experiment and anti-interference experiment showed that both target materials had good anti-interference ability and repeatability.（3）The results of repeated experiments showed that after 5adsorption-desorption tests with 1 mol/L HCl for elution,the adsorption capacity still had 83.33%（single-finger material）and 84.25%（dual-finger material）of the maximum adsorption capacity.The anti-interference experiment showed that the interfering ions had almost no effect on the adsorption.Both target materials had good anti-interference ability and repeatability（4）The Langmuir,Freundlich,and Pseudo-second-order models had good fitting results for the adsorption data of the two materials.Langmuir（Linear）model has the best fitting result for single-finger materials（R²=0.9856）;Freundlich（Nonlinear）model has the best fitting result for two-finger materials（R²=0.9948）;Pseudo-second-order（Linear）has a good fitting effect on the two materials,but the fitting effect of the two-finger material（R²=0.9931）is slightly better than that of the single-finger material（R²=0.9922）.The fitting results show that the adsorption process of the two target materials mainly followed the monolayer and chemical adsorption.In summary,this thesis had synthesized mono/bis-amidoxime-based open-chain polyether fungal modified materials,analyzed its adsorption properties for uranium,and initially explored its adsorption mechanism,and its reusability and anti-interference properties were studied.The research content of this article had certain reference and guiding significance for the application of biologically modified materials to the treatment of uranium-containing wastewater.