School of Materials Engineering, Changshu Institute of Technology, Changshu 215500, China; Suzhou Key Laboratory of Functional Ceramic Materials, Changshu Institute of Technology, Changshu 215500, China; School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116, China.
Nuclear Resources Engineering College, University of South China, Hengyang 421001, China.
J Environ Sci (China). 2021 Sep;107:14-25. doi: 10.1016/j.jes.2021.01.028. Epub 2021 Feb 6.
The layered laurylsulfonate intercalated green rust (lauryl-S GR) was synthesized to evaluate the influence of synthesis parameters and aqueous conditions on the adsorption of Ce. The maximum adsorption capacity of 305.58 mg/g by lauryl-S GR was predictably obtained. The pseudo-first-order kinetic model was appropriate in fitting the whole uptake process in a weak acid environment. Three isotherm models including Langmuir, Freundlich, and Tempkin were all reliable in depicting the isotherm adsorption process. The maximum monolayer adsorption capacity of lauryl-S GR towards Ce was 315.46 mg/g. Ce species including CeO and CeO besides CeO were matched in the XPS distribution, directly indicating the reduction reaction brought by Fe in the GR occurred to hydrated Ce ions during the adsorption. Nano-sized Ce particles attached to the lauryl-S GRs after the adsorption experiments were observed in the morphological characterization. Flocculated materials were formed on the surface of the lauryl-S GR at a pH of 7, which further reduced the active sites and disrupted the continuous uptake of Ce to the lauryl-S GR. This study expands the application of GRs and supplies an ideal iron-based material for the construction of the affiliated recovery pathway to the traditional separation of Ce.
层状十二烷基磺酸盐插层绿锈（十二烷基磺酸盐 GR）被合成以评估合成参数和水相条件对 Ce 吸附的影响。通过十二烷基磺酸盐 GR 可预测地获得最大吸附容量为 305.58mg/g。在弱酸环境中，准一级动力学模型适合拟合整个吸附过程。Langmuir、Freundlich 和 Tempkin 三种等温模型均可靠地描述了等温吸附过程。十二烷基磺酸盐 GR 对 Ce 的最大单层吸附容量为 315.46mg/g。XPS 分布中匹配了 CeO 和 CeO 以外的 CeO 物种，这直接表明吸附过程中 GR 中的 Fe 引发了对水合 Ce 离子的还原反应。在吸附实验后，在形态特征中观察到纳米级 Ce 颗粒附着在十二烷基磺酸盐 GR 上。在 pH 值为 7 时，十二烷基磺酸盐 GR 表面形成了絮状物质，这进一步减少了活性位点，并破坏了对 Ce 的连续吸附到十二烷基磺酸盐 GR。本研究扩展了 GRs 的应用，并为构建传统 Ce 分离相关的回收途径提供了理想的铁基材料。
