Ca/Al layered double hydroxide decorated carbon nanotube (Ca/Al-LDH@CNTs) composites were fabricated by co-precipitation method and hydrothermal aged treatment. The prepared Ca/Al-LDH@CNTs was characterized by SEM, TEM, EDS, XRD, FT-IR, UV–vis and XPS techniques, and applied to remove U(VI) from aqueous solutions under various environmental conditions (i.e., pH, ionic strength, temperature and contact time). The results indicated that the adsorption of U(VI) on Ca/Al-LDH@CNTs was four times higher than that of U(VI) on bare CNTs. The kinetic investigations reflected the chemisorption of U(VI) on Ca/Al-LDH@CNTs through oxygen-containing functional groups. The adsorption isotherms demonstrated that the adsorption of U(VI) was well fitted by Langmuir model and the maximum adsorption capacity of U(VI) on Ca/Al-LDH@CNTs was calculated to be 382.9 mg g −1 at 289.15 K. The thermodynamic parameters calculated from temperature-dependent isotherms suggested that U(VI) adsorption on Ca/Al-LDH@CNTs were endothermic and spontaneous process. Furthermore, Ca/Al-LDH@CNTs could remove ∼91% of 241 Am(III) at pH = 8.0, which confirmed Ca/Al-LDH@CNTs as a promising material for multiply low level radionuclides’ pollution remediation.
Haijun Chen,Zhibin Zhang,Xiangxue Wang,Jing Chen,Chao Xu,Yunhai Liu,Zhimin Yu,Xiangke Wang
Magnetic Fe/Zn layered double oxide decorated carbon nanotubes (M-Fe/Zn-LDO@CNTs) composites were synthesized via a hydrothermal method with further calcination treatment. The fabricated M-Fe/Zn-LDO@CNTs were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, UV–vis spectroscopy, scanning electron microscopy, and transmission electron microscopy and then applied for U(VI) elimination under diversiform experimental conditions, such as pH, temperature, ionic strength, contact time, and coexisting ions. The experimental results demonstrated that the U(VI) adsorption performance of M-Fe/Zn-LDO@CNTs was much higher than bare CNTs. The thermodynamic parameters revealed that U(VI) adsorption on M-Fe/Zn-LDO@CNTs was endothermic and spontaneous. More importantly, the adsorption performance of U(VI) on M-Fe/Zn-LDO@CNTs was still higher than ∼89% after five cycles. Furthermore, ∼95.9% of 241Am(III) could be removed by M-Fe/Zn-LDO@CNTs from solution at pH = 8.0, which confirmed that M-Fe/Zn-LDO@CNTs was an excellent material for efficient removal of long-lived lanthanides and actinides from environmental aqueous solutions in radionuclides’ pollution remediation.
危险品化学品经营许可证（带存储）