Feng Liujun, Chen Zhiqiang, Wang Haiyan, Chen Zhibiao, Chen Zuliang, Liu Jianhua, Zeng Yuee
School of Geographical Science, Fujian Normal University, Fuzhou, 350117, Fujian Province, China.
College of Environmental and Resource Science, Fujian Normal University, Fuzhou, 350117, Fujian Province, China.
Sci Rep. 2025 Feb 22;15(1):6486. doi: 10.1038/s41598-025-86067-y.
Phytoremediation is currently a very popular remediation method for salvaging rare earth mining sites. However, there is still a challenge concerning how to use secondary resources such as plant biomass following the extraction of rare earth elements (REEs). Herein, Dicranopteris pedata (Houtt.) Nakaike, a REEs hyperaccumulator, served to fabricate REEs-rich carbonisation materials (REEs/C) at different temperatures. The results showed that the percentages of Pb(II) removed using REEs/C prepared at 400 °C (REEs/C-4) and 800 °C (REEs/C-8) were 85.1% and 84.0%, respectively. These amounts were better than that of REEs-C prepared at 600 °C (REEs/C-6 (67.0%)). Characterisation analysis confirmed that rich functional groups like aromatic, hydroxyl and C = C/C-C in REEs/C-4 provided more chelation sites to effectively complex with Pb(II), while the superior removal capacity of REEs/C-8 resulted from the enrichment of more REEs and abundant pore structure. Chemisorption, such as ion exchange and chelation, plays a significant role in adsorption. During the carbonisation process of REEs/C, the REEs enriched in Dicranopteris pedata contributed to the formation of rare earth oxides and oxygen vacancies in the material, and these properties enhanced the Pb removal ability of REEs/C. Moreover, the REEs contained in the material did not cause a leaching phenomenon during Pb removal, which is a safe and environmentally friendly material. Finally, the REEs/C was applied to wastewater, and it was found that this material could effectively adsorb Pb from wastewater. Overall, this study generates a new insight into: firstly, how to use phytoextracted biomass containing REEs as valuable REEs/C materials; and secondly, how to save the environment by using technology that promotes recycling of used materials.
植物修复是目前用于修复稀土矿开采场地的一种非常流行的修复方法。然而，在稀土元素（REEs）提取后如何利用植物生物质等二次资源仍然是一个挑战。在此，以稀土元素超积累植物芒萁（Dicranopteris pedata (Houtt.) Nakaike）为原料，在不同温度下制备了富含稀土元素的碳化材料（REEs/C）。结果表明，在400℃（REEs/C-4）和800℃（REEs/C-8）制备的REEs/C对Pb(II)的去除率分别为85.1%和84.0%。这些去除率优于在600℃制备的REEs/C（REEs/C-6，去除率为67.0%）。表征分析证实，REEs/C-4中丰富的芳香族、羟基和C = C/C-C等官能团提供了更多的螯合位点，能有效地与Pb(II)络合，而REEs/C-8的优异去除能力则源于更多稀土元素的富集和丰富的孔隙结构。化学吸附，如离子交换和螯合，在吸附过程中起重要作用。在REEs/C的碳化过程中，芒萁中富集的稀土元素有助于材料中稀土氧化物和氧空位的形成，这些特性增强了REEs/C对Pb的去除能力。此外，材料中的稀土元素在去除Pb的过程中没有引起浸出现象，是一种安全环保的材料。最后，将REEs/C应用于废水处理，发现该材料能有效吸附废水中的Pb。总体而言，本研究产生了新的见解：一是如何将含稀土元素的植物提取生物质用作有价值的REEs/C材料；二是如何通过促进废旧材料回收利用的技术来保护环境。
