College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China; School of Chemistry, Biological and Materials Sciences, East China University of Technology, Nanchang, 330013, PR China.
College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China.
J Hazard Mater. 2018 Apr 5;347:67-77. doi: 10.1016/j.jhazmat.2017.12.062. Epub 2017 Dec 25.
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 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 Am(III) at pH = 8.0, which confirmed Ca/Al-LDH@CNTs as a promising material for multiply low level radionuclides' pollution remediation.
钙/铝层状双氢氧化物修饰碳纳米管（Ca/Al-LDH@CNTs）复合材料通过共沉淀法和水热老化处理制备。通过 SEM、TEM、EDS、XRD、FT-IR、UV-vis 和 XPS 技术对制备的 Ca/Al-LDH@CNTs 进行了表征，并在各种环境条件（即 pH、离子强度、温度和接触时间）下应用于从水溶液中去除 U(VI)。结果表明，Ca/Al-LDH@CNTs 对 U(VI)的吸附是 bare CNTs 的四倍。动力学研究反映了 U(VI)通过含氧官能团在 Ca/Al-LDH@CNTs 上的化学吸附。吸附等温线表明，U(VI)的吸附很好地符合 Langmuir 模型，在 289.15 K 下 Ca/Al-LDH@CNTs 对 U(VI)的最大吸附容量计算为 382.9 mg g。从温度依赖性等温线上计算出的热力学参数表明，U(VI)在 Ca/Al-LDH@CNTs 上的吸附是吸热和自发的过程。此外，Ca/Al-LDH@CNTs 可以在 pH = 8.0 时去除约 91%的 Am(III)，这证实了 Ca/Al-LDH@CNTs 是一种很有前途的多低水平放射性核素污染修复材料。
