Preparation And Performance Of Amidoximated Polyacrylonitrile Foamed Uranium Adsorbent With Solar Energy Evaporation Ability

With the rapid development of science and technology,the application of nuclear energy in various fields is increasing,such as:nuclear weapons,nuclear power,nuclear power,etc.,and the resulting U（VI）containing wastewater is gradually increasing.The research on rational disposal of wastewater containing U（VI）has also increased.On the one hand,this move can reduce the harm of nuclear pollution to the environment and human health;on the other hand,the precious U（VI）element in the wastewater containing U（VI）can be recycled and reused.Therefore,the extraction of U（VI）element in nuclear wastewater and the purification of water have important practical significance,and this paper is just around this theme.In this paper,polyacrylonitrile powder（PAN）was used as raw material to prepare amidoximized polyacrylonitrile foam U（VI）adsorption material（AOPAN-U）with unidirectional pores by unidirectional freezing method.On this basis,two amidoximated polyacrylonitrile foam U（VI）adsorbents with solar evaporation ability,AOPAN-U-CB/AOPAN-U-NM,were prepared by one-step and two-step methods,respectively.The U（VI）adsorption and evaporation properties were investigated.Polyacrylonitrile foams with unidirectional pores（PAN-U）were prepared by unidirectional freezing method,and then amidoximedized as polyacrylonitrile foams（AOPAN-U）with higher U（VI）adsorption properties.AOPAN-U has good U（VI）adsorption performance and structural strength.During static adsorption.The maximum adsorption capacity was 327.3mg·g^-1.In various competitive ion adsorption experiments,AOPAN-U showed high selectivity for U（VI）with an adsorption capacity of 173.2 mg·g^-1.After multiple elution-adsorption experiments,AOPAN-U still has good recycling performance.The adsorption kinetics and thermodynamic analysis showed that the adsorption process of U（VI）by AOPAN-U was dominated by chemical adsorption,which conformed to the pseudo-second-order kinetic model and was dominated by monolayer adsorption,which conformed to the Langmuir model.The carbon black（CB）modified polyacrylonitrile foam（PAN-U-CB）with solar evaporation ability was prepared by a one-step method,and after amidoximation,it was used as an amidoximated polyacrylonitrile with solar evaporation ability.Foam U（VI）adsorbent material（AOPAN-U-CB）.Under the condition of a simulated sunlight intensity（1 sun）,the maximum evaporation rate of PAN-U-CB is 1.372 kg·m^-2·h^-1.During dynamic adsorption,the maximum evaporation rate of AOPAN-U-CB is 1.651 kg·m^-2·h^-1 and the adsorption capacity of U（VI）is 1401.6 g·m^-2.Polyacrylonitrile foams（PAN-U-NM）with solar evaporation ability based on carbon black（CB）modified nanofiber membranes were prepared by a two-step method.After amidoximation,it can be used as amidoximation polyacrylonitrile foam U（VI）adsorption material（AOPAN-U-NM）with solar evaporation ability.Under the condition of a simulated sunlight intensity（1 sun）,the maximum evaporation rate of PAN-U-NM is 1.139 kg·m^-2·h^-1.During dynamic adsorption.the maximum evaporation rate of AOPAN-U-NM is 1.470 kg·m^-2·h^-1 and the adsorption capacity of U（VI）is 1673.6 g·m^-2.