Qiu Xinran, Ding Ling, Zhang Chi, Ouyang Zhuozhi, Jia Hanzhong, Guo Xuetao, Zhu Lingyan
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.
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.
J Hazard Mater. 2022 Aug 5;435:128994. doi: 10.1016/j.jhazmat.2022.128994. Epub 2022 Apr 25.
Nanoplastics (NPs), which are often detected in the natural environment, are regarded as a group of emerging pollutants. Hematite is a substance that exists widely in the surface environment and has an important impact on the environmental behavior of pollutants. Clarifying the migration of NPs requires an in-depth understanding of intrinsic interaction mechanisms of NPs with iron-containing minerals. The interaction process of polystyrene nanoplastics (PSNPs) on the hematite exposed facets was systematically studied by experiments under different conditions, adsorption isotherm curves, Fourier Transform infrared (FTIR) spectroscopy and two-dimensional correlation spectroscopy (2D-COS) analyses. We found that PSNPs were adsorbed on the three exposed faces of hematite ({001}, {012}, and {100}) by electrostatic interaction, respectively, but the capacities for PSNPs were different. Adsorption models were established to explore the preferred interaction surface dependent on the exposed facets, and it was found that {012} surfaces were more favorable for PSNPs adsorption, while {001} surface has better adsorption capacity for PSNPs than {100} surface, which is due to the different density and proportion of hydroxyl groups on the exposed facets of hematite. These findings elucidated the dependence of PSNPs adsorption on the hematite facets, and illustrated t the effect of hematite on the migration of PSNPs in the environment.
纳米塑料（NPs）在自然环境中经常被检测到，被视为一类新兴污染物。赤铁矿是一种广泛存在于地表环境中的物质，对污染物的环境行为有重要影响。阐明纳米塑料的迁移需要深入了解纳米塑料与含铁矿物的内在相互作用机制。通过在不同条件下的实验、吸附等温线曲线、傅里叶变换红外光谱（FTIR）和二维相关光谱（2D-COS）分析，系统研究了聚苯乙烯纳米塑料（PSNPs）在赤铁矿暴露晶面上的相互作用过程。我们发现，PSNPs分别通过静电相互作用吸附在赤铁矿的三个暴露面上（{001}、{012}和{100}），但对PSNPs的吸附能力不同。建立了吸附模型以探索依赖于暴露晶面的优先相互作用表面，发现{012}表面对PSNPs吸附更有利，而{001}表面对PSNPs的吸附能力比{100}表面更好，这是由于赤铁矿暴露晶面上羟基的密度和比例不同。这些发现阐明了PSNPs吸附对赤铁矿晶面的依赖性，并说明了赤铁矿对PSNPs在环境中迁移的影响。
