Yang Yalin, Yan Qiuting, Weng Xiulan, Owens Gary, Chen Zuliang
Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental and Resource Sciences, Fujian Normal University, Fuzhou, Fujian 350117, China.
Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental and Resource Sciences, Fujian Normal University, Fuzhou, Fujian 350117, China.
Water Res. 2023 Oct 1;244:120486. doi: 10.1016/j.watres.2023.120486. Epub 2023 Aug 13.
While rare earth elements (REEs) play key roles in many modern technologies, the selectivity of recovering of REEs from mining wastewater remains a critical problem. In this study, iron nanoparticles (FeNPs) synthesized from euphorbia cochinchinensis extracts were successfully used for selective recovery of REEs from real mining wastewater with removal efficiencies of 89.4% for Y(III), 79.8% for Ce(III) and only 6.15% for Zn(Ⅱ). FTIR and XPS analysis suggested that the high selective removal efficiency of Y(III) and Ce(III) relative to Zn(Ⅱ) on FeNPs was due to a combination of selective REEs adsorption via complexing with O or N, ion exchange with H present in functional groups contained within the capping layer and electrostatic interactions. Adsorptions of Y(III) and Ce(III) on FeNPs conformed to pseudo second-order kinetics and the Langmuir isotherm model with maximum adsorption capacities of 5.10 and 0.695 mg∙g, respectively. The desorption efficiencies of Y(III) and Ce(III) were, respectively, 95.0 and 97.9% in 0.05 M acetic acid, where desorption involved competitive ion exchange between Y(III), Ce(III) and Zn(Ⅱ) with H contained in acetic acid and intraparticle diffusion. After four consecutive adsorption-desorption cycles, adsorption efficiencies for Y(III) and Ce(III) remained relatively high at 52.7% and 50.1%, respectively, while desorption efficiencies of Y(III) and Ce(III) were > 80.0% and 95.0%, respectively. Overall, excellent reusability suggests that FeNPs can practically serve as a potential high-quality selectivity material for recovering REEs from mining wastewaters.
虽然稀土元素（REEs）在许多现代技术中发挥着关键作用，但从采矿废水中回收稀土元素的选择性仍然是一个关键问题。在本研究中，由铁苋菜提取物合成的铁纳米颗粒（FeNPs）成功用于从实际采矿废水中选择性回收稀土元素，对Y(III)的去除效率为89.4%，对Ce(III)的去除效率为79.8%，而对Zn(Ⅱ)的去除效率仅为6.15%。傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）分析表明，相对于Zn(Ⅱ)，FeNPs对Y(III)和Ce(III)具有高选择性去除效率，这是由于通过与O或N络合进行选择性稀土吸附、与封端层中官能团所含的H进行离子交换以及静电相互作用的综合作用。Y(III)和Ce(III)在FeNPs上的吸附符合准二级动力学和朗缪尔等温线模型，最大吸附容量分别为5.10和0.695 mg∙g。Y(III)和Ce(III)在0.05 M乙酸中的解吸效率分别为95.0%和97.9%，解吸过程涉及Y(III)、Ce(III)和Zn(Ⅱ)与乙酸中所含H的竞争性离子交换以及颗粒内扩散。经过四个连续的吸附-解吸循环后，Y(III)和Ce(III)的吸附效率分别保持在相对较高的52.7%和50.1%，而Y(III)和Ce(III)的解吸效率分别>80.0%和95.0%。总体而言，出色的可重复使用性表明FeNPs实际上可作为从采矿废水中回收稀土元素的潜在高质量选择性材料。
