The adsorption of uranium(Ⅵ)on the manganese oxide coated zeolite(MOCZ)from aqueous solution was investigated in a fixed-bed column.The experiments were conducted to investigate the effects of bed height,flow rate,pa...The adsorption of uranium(Ⅵ)on the manganese oxide coated zeolite(MOCZ)from aqueous solution was investigated in a fixed-bed column.The experiments were conducted to investigate the effects of bed height,flow rate,particle size,initial concentration of uranium(Ⅵ),initial pH,presence of salt and competitive ions.The U-uptake by MOCZ increased with initial uranium(Ⅵ)concentration and bed height,but decreased as the flow rate and particle size increased.In the presence of salt and competitive ions,the breakthrough time was shorter.The adsorption capacity reached a maximum at pH of 6.3.The Thomas model was applied to the experimental data to determine the characteristic parameters of the column for process design using linear regression.The breakthrough curves calculated from the model were in good agreement with the experimental data.The BDST model was used to study the influence of bed height on the adsorption of uranium(Ⅵ).Desorption of uranium(Ⅵ)in the MOCZ column was investigated.The column could be used for at least four adsorption-desorption cycles using 0.1mol.L-1 NaHCO3 solution as the elution.After desorption and regeneration with deionized water,MOCZ could be reused to adsorb uranium(Ⅵ)at a comparable capacity.Compared to raw zeolite,MOCZ showed better capacity for uranium(Ⅵ)removal.展开更多
Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with d...Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with different aspect ratios are precisely constructed and applied for piezo-photocatalytic reduction of U(Ⅵ)for the first time.The ultrasonic(60 kHz,100 W)induces piezoelectric potential to generate a 0.57 eV A^(-1)electric field,which is added to the direction of CdS(010)as a driving force to efficiently separate photogenerated charges.The alliance between piezoelectric effect and photocatalytic activity endows CdS NW-3 with the fastest piezo-photocatalytic rate under ultrasonic vibration and 5 W LED irradiation,and the relevant rate constant(0.042 min^(-1))is about 12 and 53.8 times than that of LED and ultrasonication.More importantly,93.74%of U(Ⅵ)could be removed from natural uranium mine wastewater.Therefore,this piezo-photocatalysis system that reduces U(Ⅵ)to easily separable(UO_(2))O_(2)·2H_(2)O(s)provides valuable input for disposal applications of radioactive wastewater and broadens the horizons of nuclear energy utilization toward the advancement of carbon neutrality.展开更多
The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, tempera...The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, temperature and complex anions (C2O24-) on the distribution ratio was studied.展开更多
基金Supported by the National Science Foundation for Postdoctoral Sciemists of China （20070420811） and the Science and Technology Department of Henan Province in China （200510459016）.
文摘The adsorption of uranium(Ⅵ)on the manganese oxide coated zeolite(MOCZ)from aqueous solution was investigated in a fixed-bed column.The experiments were conducted to investigate the effects of bed height,flow rate,particle size,initial concentration of uranium(Ⅵ),initial pH,presence of salt and competitive ions.The U-uptake by MOCZ increased with initial uranium(Ⅵ)concentration and bed height,but decreased as the flow rate and particle size increased.In the presence of salt and competitive ions,the breakthrough time was shorter.The adsorption capacity reached a maximum at pH of 6.3.The Thomas model was applied to the experimental data to determine the characteristic parameters of the column for process design using linear regression.The breakthrough curves calculated from the model were in good agreement with the experimental data.The BDST model was used to study the influence of bed height on the adsorption of uranium(Ⅵ).Desorption of uranium(Ⅵ)in the MOCZ column was investigated.The column could be used for at least four adsorption-desorption cycles using 0.1mol.L-1 NaHCO3 solution as the elution.After desorption and regeneration with deionized water,MOCZ could be reused to adsorb uranium(Ⅵ)at a comparable capacity.Compared to raw zeolite,MOCZ showed better capacity for uranium(Ⅵ)removal.
基金financially supported by the National Natural Science Foundation of China(22276030,22206024,U2167223,22076022)Jiangxi Provincial Natural Science Foundation(20232BAB213034,20232ACB203011)
文摘Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with different aspect ratios are precisely constructed and applied for piezo-photocatalytic reduction of U(Ⅵ)for the first time.The ultrasonic(60 kHz,100 W)induces piezoelectric potential to generate a 0.57 eV A^(-1)electric field,which is added to the direction of CdS(010)as a driving force to efficiently separate photogenerated charges.The alliance between piezoelectric effect and photocatalytic activity endows CdS NW-3 with the fastest piezo-photocatalytic rate under ultrasonic vibration and 5 W LED irradiation,and the relevant rate constant(0.042 min^(-1))is about 12 and 53.8 times than that of LED and ultrasonication.More importantly,93.74%of U(Ⅵ)could be removed from natural uranium mine wastewater.Therefore,this piezo-photocatalysis system that reduces U(Ⅵ)to easily separable(UO_(2))O_(2)·2H_(2)O(s)provides valuable input for disposal applications of radioactive wastewater and broadens the horizons of nuclear energy utilization toward the advancement of carbon neutrality.
文摘The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, temperature and complex anions (C2O24-) on the distribution ratio was studied.
