Wan Quan, Liu Beibei, Zhang Miaoyue, Zhao Man, Dai Yuan, Liu Wenshen, Ding Kengbo, Lin Qingqi, Ni Zhuobiao, Li Jingjing, Wang Shizhong, Jin Chao, Tang Yetao, Qiu Rongliang
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China.
J Hazard Mater. 2023 Jul 5;453:131390. doi: 10.1016/j.jhazmat.2023.131390. Epub 2023 Apr 11.
The present study investigated the co-transport behavior of three REEs (La, Gd, and Yb) with and without biochar nanoparticles (BC NPs) in water-saturated porous media. The presence of REEs enhanced the retention of BC NPs in quartz sand (QS) due to decreased electrostatic repulsion between BC NPs and QS, enhanced aggregation of BC NPs, and the contribution of straining. The distribution coefficients (K) in packed columns in the co-transport of BC NPs and three REEs were much smaller than in batch experiments due to the different hydrodynamic conditions. In addition, we, for the first time, found that REE fractionation in the solid-liquid phase occurred during the co-transport of REEs in the presence and absence of BC NPs. Note that the REE fractionation during the co-transport, which is helpful for the tracing application during earth surface processes, was driven by the interaction of REEs with QS and BC NPs. This study elucidates novel insights into the fate of BC NPs and REEs in porous media and indicates that (i) mutual effects between BC NPs and REE should be considered when BC was applied to REE contaminated aquatic and soil systems; and (ii) REE fractionation provides a useful tool for identifying the sources of coexisting substances.
本研究调查了三种稀土元素（La、Gd和Yb）在有无生物炭纳米颗粒（BC NPs）存在的情况下在水饱和多孔介质中的共运移行为。稀土元素的存在增强了BC NPs在石英砂（QS）中的保留，这是由于BC NPs与QS之间的静电排斥力降低、BC NPs的聚集增强以及过滤作用的贡献。由于流体动力学条件不同，BC NPs与三种稀土元素共运移时填充柱中的分配系数（K）远小于批量实验中的分配系数。此外，我们首次发现，在有和没有BC NPs存在的情况下，稀土元素共运移过程中会发生固液相稀土元素分馏。值得注意的是，共运移过程中的稀土元素分馏有助于地表过程中的示踪应用，它是由稀土元素与QS和BC NPs的相互作用驱动的。本研究阐明了BC NPs和稀土元素在多孔介质中归宿的新见解，并表明：（i）当将生物炭应用于稀土污染的水生和土壤系统时，应考虑BC NPs与稀土元素之间的相互影响；（ii）稀土元素分馏为识别共存物质的来源提供了一种有用的工具。
