Yang Weisen, Shi Fengshuo, Jiang Wenlong, Chen Yuhuang, Zhang Kaiyin, Jian Shaoju, Jiang Shaohua, Zhang Chunmei, Hu Jiapeng
Fujian Key Laboratory of Eco-Industrial Green Technology, College of Ecology and Resources Engineering, Wuyi University Wuyishan 354300 China
College of Mechanical and Electrical Engineering, Wuyi University Wuyishan 354300 China.
RSC Adv. 2022 Oct 26;12(47):30522-30528. doi: 10.1039/d2ra06284d. eCollection 2022 Oct 24.
A La-based adsorbent was prepared with La(NO)·6HO, 2-methylimidazole and DMF amide-hydrolysis and used for fluoride decontamination from aqueous water. The obtained adsorbent was lanthanum methanoate (La(COOH)). The effects of pH value, initial F concentration and interfering ions on defluoridation properties of as-prepared La(COOH) were assessed through batch adsorption tests. The adsorption kinetics, isotherm models and thermodynamics were employed to verify the order, nature and feasibility of La(COOH) towards fluoride removal. The results imply that La(COOH) is preferable for defluoridation over a wide pH range of 2 to 9 without interference. Simultaneously, the defluoridation process of La(HCOO) accords to the pseudo-second order model and Langmuir isotherm, revealing chemical adsorption is the main control step. The maximum fluoride capture capacities of La(COOH) at 30, 40 and 50 °C are 245.02, 260.40 and 268.99 mg g, respectively. The mechanism for defluoridation by La(COOH) was revealed by PXRD and XPS. To summarize, the as-synthesized La based adsorbent could serve as a promising adsorbent for defluoridation from complex fluoride-rich water.
以La(NO₃)₃·6H₂O、2-甲基咪唑和N,N-二甲基甲酰胺为原料，通过酰胺水解法制备了一种镧基吸附剂，并将其用于去除水溶液中的氟化物。所得吸附剂为甲酸镧（La(COOH)₂）。通过批量吸附试验评估了pH值、初始氟浓度和干扰离子对所制备的La(COOH)₂脱氟性能的影响。采用吸附动力学、等温线模型和热力学方法来验证La(COOH)₂对氟去除的反应级数、性质和可行性。结果表明，La(COOH)₂在2至9的宽pH范围内具有良好的脱氟性能且不受干扰。同时，La(HCOO)₂的脱氟过程符合准二级模型和朗缪尔等温线，表明化学吸附是主要控制步骤。La(COOH)₂在30、40和50℃下的最大氟捕获容量分别为245.02、260.40和268.99 mg/g。通过粉末X射线衍射（PXRD）和X射线光电子能谱（XPS）揭示了La(COOH)₂的脱氟机理。综上所述，所合成的镧基吸附剂有望成为从复杂富氟水中脱氟的吸附剂。
