College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China.
Water Res. 2022 Jul 1;219:118544. doi: 10.1016/j.watres.2022.118544. Epub 2022 May 4.
With the massive use and discarding of plastic products, plastic particles, including nanoplastics (NPs), which are continuously released under the action of environmental factors, are posing greater risk to the ecosystem and human health. NPs exposed to the environment experience aging, which can significantly change their physical and chemical properties and affect their environmental behavior. Here, we examined the adsorption behavior of polystyrene nanoplastic (PSNP) aging by ultraviolet (UV) exposure on different minerals (goethite, magnetite, kaolinite and montmorillonite). Aging not only changes the surface morphology of PSNP, but also increases the surface negative charge and produces a large number of oxygen-containing functional groups (OFGs). Incubation of aged PSNP with minerals indicated that iron oxides (goethite and magnetite) showed stronger interactions with aged PSNP than pristine PSNP, and there was an interaction between clay minerals and aged PSNP. The adsorption experiments and scanning electron microscopy (SEM) suggested that the higher adsorption capacity of a mineral surface to aged PSNP may be related to electrostatic attraction and ligand exchange. The Fourier transform infrared (FTIR) spectra after adsorption showed that the adsorption affinity between the functional groups was different, and two-dimensional correlation spectroscopy (2D-COS) analysis further indicated that the mineral preferentially adsorbed the aged PSNP in accordance with the order of OFGs. The findings provide a theoretical basis for scientific evaluation of ecological risks of NPs in the environment.
随着塑料制品的大量使用和丢弃，包括纳米塑料（NPs）在内的塑料颗粒在环境因素的作用下不断释放，对生态系统和人类健康构成了更大的风险。暴露于环境中的 NPs 会经历老化，这会显著改变它们的物理和化学性质，并影响它们的环境行为。在这里，我们研究了紫外线（UV）暴露对不同矿物质（针铁矿、磁铁矿、高岭土和蒙脱石）上聚苯乙烯纳米塑料（PSNP）老化的吸附行为。老化不仅改变了 PSNP 的表面形貌，还增加了表面负电荷并产生了大量的含氧官能团（OFGs）。将老化的 PSNP 与矿物质一起孵育表明，氧化铁（针铁矿和磁铁矿）与老化的 PSNP 的相互作用比原始 PSNP 更强，并且粘土矿物质与老化的 PSNP 之间存在相互作用。吸附实验和扫描电子显微镜（SEM）表明，矿物质表面对老化 PSNP 的更高吸附能力可能与静电吸引和配体交换有关。吸附后的傅里叶变换红外（FTIR）光谱表明，官能团之间的吸附亲和力不同，二维相关光谱（2D-COS）分析进一步表明，矿物质优先按照 OFGs 的顺序吸附老化的 PSNP。这些发现为科学评估环境中 NPs 的生态风险提供了理论依据。
