Properties Of Electroadsorbed Uranyl Ions

With the rapid development of the nuclear industry,the treatment of radioactive waste has become the main reason restricting the development of the nuclear industry.Capacitive deionization technology can efficiently adsorb uranium ions in wastewater and purify uranium-containing wastewater by using the double electric layer principle.Electrode material is a key factor affecting the performance of capacitor deionization,which requires excellent electrical performance,stable chemical properties,anti-irradiation,and large specific surface area.Carbon electrode with the above characteristics has become a research hotspot.Based on the above problems,this paper studies the capacity of activated carbon and graphene carbon electrodes to capacitantly deionized uranium.The main research contents are as follows:?1?activated carbon was used as electrode material to construct the electroadsorption test unit,and its electroadsorption performance to uranyl ion(UO₂²⁺)was studied.The morphology and structure of activated carbon were characterized by SEM and BET,which showed that activated carbon had multi-stage pore structure and large specific surface area.At the same time,the electrochemical properties of the activated carbon were tested,and the electrosorptive performance of activated carbon to UO₂²⁺under different voltages was studied.The experimental results showed that,within the range of 1.2-1.8v applied voltage,the electroadsorption performance of activated carbon increased with the rise of voltage,but the excessive voltage?>1.8v?may be due to electrode polarization or ionization,the electroadsorption performance decreased.Under the applied voltage of 1.8v,the saturated adsorption capacity of activated carbon electrode material to uranium was 86.05mg/g,and the adsorption rate was 0.28mg/?g·min?,indicating its potential performance as an electrode material for electroadsorption of UO₂²⁺.?2?three-dimensional graphene?3DG?electrode materials are prepared by hydrothermal reduction using graphene oxide as precursor,and its morphology and structure are characterized by SEM,BET,XRD,Raman,FTIR and Tg,and also its electrochemical performance are also measured.The results showed that 3DG materials possessed multi-stage hole structure,large specific surface area,high specific capacitance and low impedance.Then,capacitance deionization test module was constructed to study the electrical adsorption performance of 3DG for UO₂²⁺under different voltages.The results showed that the electrical adsorption performance increased with the increase of voltage in the range of1.2-1.8v,but decreased when the voltage was too high?>1.8v?,possibly due to the electrode polarization or ionization.Under the applied voltage of 1.8v,the saturated adsorption capacity of 3DG electrode materials for UO₂²⁺is 113.80mg/g and the adsorption rate is 0.32mg/?g·min?.