JES编辑推荐：纳米硒在水体中的团聚稳定性行为研究

Aggregation and stability of selenium nanoparticles: Complex roles of surface coating, electrolytes and natural organic matter

Sujuan  Yu, Hao Liu, Rui Yang, Wenjing Zhou, Jingfu Liu^*

https://doi.org/10.1016/j.jes.2022.10.025

纳米硒肥料的施用可能会导致纳米硒释放到水生系统中。然而，纳米硒的环境行为却很少研究。本研究以海藻酸包覆的纳米硒(Alg-SeNPs)和聚乙烯醇包覆的纳米硒(PVA-SeNPs)为模型，系统研究了纳米硒在不同水质条件下的团聚稳定性。PVA-SeNPs在单价和多价电解质中具有很高的稳定性，这可能是由于包裹剂聚乙烯醇具有很强的空间位阻作用。即使在2500 mmol/L NaCl和200 mmol/L MgCl₂溶液中，Alg-SeNPs的粒径也只有轻微的增长，而在CaCl₂和LaCl₃溶液中，它们发生了明显的聚集。Ca²⁺和La³⁺与海藻酸中的表面官能团结合，诱导形成了交联的团聚体。天然有机物增强了Alg-SeNPs在NaCl溶液中的稳定性，由于天然有机质与Ca²⁺阳离子桥联效应，加速了Alg-SeNPs的团聚。SeNPs分散在不同的实际天然水体中30天后，Alg-SeNPs和PVA-SeNPs的粒径增加到数百纳米或10 μm以上，说明SeNPs可能长时间悬浮在水体中或进一步发生沉淀，取决于实际水体的化学性质。该研究有助于深入了解水生环境中纳米硒的归趋。SeNPs在不同水体中的悬浮特性也提示我们需关注纳米硒对生活在不同水体深度的生物的风险。

纳米硒的表面性质、水体中的天然有机质及电解质种类显著影响纳米硒在水环境中的稳定性。

The application of selenium nanoparticles (SeNPs) as nanofertilizers may lead to the release of SeNPs into aquatic systems. However, the environmental behavior of SeNPs is rarely studied. In this study, using alginate-coated SeNPs (Alg-SeNPs) and polyvinyl alcohol-coated SeNPs (PVA-SeNPs) as models, we systematically investigated the aggregation and stability of SeNPs under various water conditions. PVA-SeNPs were highly stable in mono- and polyvalent electrolytes, probably due to the strong steric hindrance of the capping agent. Alg-SeNPs only suffered from a limited increase in size, even at 2500 mmol/L NaCl and 200 mmol/L MgCl₂, while they underwent apparent aggregation in CaCl₂ and LaCl₃ solutions. The binding of Ca²⁺ and La³⁺ with the guluronic acid part in alginate induced the formation of cross-linking aggregates. Natural organic matter enhanced the stability of Alg-SeNPs in monovalent electrolytes, while accelerated the attachment of Alg-SeNPs in polyvalent electrolytes, due to the cation bridge effects. The long-term stability of SeNPs in natural water showed that the aggregation sizes of Alg-SeNPs and PVA-SeNPs increased to several hundreds of nanometers or above 10 μm after 30 days, implying that SeNPs may be suspended in the water column or further settle down, depending on the surrounding water chemistry. The study may contribute to the deep insight into the fate and mobility of SeNPs in the aquatic environment. The varying fate of SeNPs in different natural waters also suggests that the risks of SeNPs to organisms living in diverse depths in the aquatic compartment should be concerned.

第一作者

于素娟，副研究员，于2014年在中科院生态环境研究中心获得理学博士学位，现任中科院生态环境研究中心副研究员。主要研究方向为微纳颗粒物的分析方法与环境行为。以第一/通讯作者在Environ. Sci. Technol.、Anal. Chem.、Sci. Total Environ.、Environ. Pollut.、Environ. Sci.: Nano等发表发表论文20多篇。

通讯作者

刘景富，教授，现任江汉大学教授。主要研究方向为微纳颗粒物和持久性有毒污染物的分析方法和环境行为与效应，以及环境功能纳米材料的制备与应用等。在Chem. Rev.、Adv. Mater.、ACS Nano、Anal. Chem.、Environ. Sci. Technol.等期刊发表论文300余篇，主编出版中英文专著各1部，获授权发明专利10余件，论文SCI引用13000余次。2006年入选中科院“百人计划”，2010年获国家杰出青年科学基金，2018和2011年分别以第一和第三完成人2次获国家自然科学二等奖。

https://www.sciencedirect.com/science/article/pii/S1001074222005149

Sujuan Yu, Hao Liu, Rui Yang, Wenjing Zhou, Jingfu Liu, 2023. Aggregation and stability of selenium nanoparticles: Complex roles of surface coating, electrolytes and natural organic matter. J. Environ. Sci. 130, 14-23.