Liu Ning, Kong Yu, Cao Xuesong, Yue Le, Wang Zhenyu, Li Xiaona
Institute of Environmental Processes and Pollution Control, School of Environment and Ecology, Jiangnan University, Wuxi 214122, China.
Institute of Environmental Processes and Pollution Control, School of Environment and Ecology, Jiangnan University, Wuxi 214122, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, China.
J Hazard Mater. 2024 May 15;470:134192. doi: 10.1016/j.jhazmat.2024.134192. Epub 2024 Apr 1.
Nanoplastics (NPs) inevitably interact with iron minerals (IMs) after being released into aquatic environments, changing their transport and fate. In this study, batch heteroaggregation kinetics of four types of NPs, i.e., polymethyl methacrylate (PMMA), polystyrene (PS-Bare), amino-polystyrene (PS-NH), and carboxyl-polystyrene (PS-COOH), with two different IMs (hematite and magnetite) were conducted. We found that the heteroaggregation of NPs and IMs and the associated interfacial interaction mechanisms are both NPs-dependent and IMs-dependent. Specifically, the NPs had stronger heteroaggregation with hematite than magnetite; the heteroaggregation order of two IMs with NPs was PMMA > PS-NH > PS-Bare > PS-COOH. Moreover, hydrogen bond, complexation, hydrophobic, cation-π, and electrostatic interaction were involved in the interfacial reaction between NPs and hematite, and electrons were transferred from the NPs to the hematite, causing the reduction of Fe into Fe. Furthermore, we first revealed that both pre-homoaggregation of NPs and IMs could affect their subsequent heteroaggregation, and the homoaggregates of IMs could be interrupted by PMMA or PS-COOH NPs introduction. Therefore, the emerging NPs pollution is likely to generate an ecological effect in terms of elemental cycles such as iron cycle. This work provides new insights into assessing the environmental transfer and ecological effects of NPs in aquatic environments.
纳米塑料（NPs）释放到水生环境后不可避免地会与铁矿物（IMs）相互作用，从而改变它们的迁移和归宿。在本研究中，开展了四种类型的纳米塑料，即聚甲基丙烯酸甲酯（PMMA）、聚苯乙烯（PS-Bare）、氨基聚苯乙烯（PS-NH）和羧基聚苯乙烯（PS-COOH）与两种不同铁矿物（赤铁矿和磁铁矿）的批量异质凝聚动力学研究。我们发现，纳米塑料与铁矿物的异质凝聚及其相关的界面相互作用机制既依赖于纳米塑料，也依赖于铁矿物。具体而言，纳米塑料与赤铁矿的异质凝聚比与磁铁矿的更强；两种铁矿物与纳米塑料的异质凝聚顺序为PMMA > PS-NH > PS-Bare > PS-COOH。此外，氢键、络合、疏水、阳离子-π和静电相互作用参与了纳米塑料与赤铁矿之间的界面反应，并且电子从纳米塑料转移到赤铁矿，导致Fe还原为Fe。此外，我们首次揭示，纳米塑料和铁矿物的预同质性凝聚都会影响它们随后的异质凝聚，并且引入PMMA或PS-COOH纳米塑料会中断铁矿物的同质性聚集体。因此，新出现的纳米塑料污染可能会在诸如铁循环等元素循环方面产生生态效应。这项工作为评估纳米塑料在水生环境中的环境迁移和生态效应提供了新的见解。
