| 引用本文: | 刘洁,张智超,李霞,朱丽帆,蒋晖.三峡水库微塑料与悬沙的聚集特性及作用机制.湖泊科学,2025,37(1):149-158. DOI:10.18307/2025.0125 |
| Liu Jie,Zhang Zhichao,Li Xia,Zhu Lifan,Jiang Hui.Aggregation characterization and mechanism of microplastics and suspended sand in the Three Gorges Reservoir. J. Lake Sci.2025,37(1):149-158. DOI:10.18307/2025.0125 |
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| 摘要: |
本文依据三峡库区悬沙矿物组成和泥沙级配为依据配置沙样，选择长江上游典型微塑料PMMA和PS，在自制大型水箱中开展水流剪切作用下微塑料和泥沙异质聚集实验，分析微—泥絮团的形态特征和聚集机制。结果表明在水流紊动剪切作用下，相比泥沙同质聚集的絮团粒径，微—泥异质聚集的絮团粒径更大，且每毫升样品中微—泥絮团上的微塑料吸附数量随水流剪切率增大而迅速增加。扫描电镜和能谱分析结果表明，在水动力条件下泥沙与PMMA、PS微球发生异质聚集，聚集过程中存在电子转移和化学态的转变，并产生不饱和键 （C  C）。由于PMMA官能团的结合能变化比PS大，此过程失电子更多、表面电荷更大，更容易与泥沙发生聚集。 |
| 关键词: 微塑料 悬沙 微—泥絮团形貌 聚集机制 三峡水库 |
| DOI：10.18307/2025.0125 |
| 分类号: |
| 基金项目:国家重点研发计划项目(2023YFB2604700)；国家自然科学基金项目（52109077）；重庆市技术创新与应用发展重点项目(CSTB2022TIAD-KPX0198)；重庆市水利科技项目(CQSLK-2022001)；水利部重大科技项目（SKS-2022076）联合资助 |
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| Aggregation characterization and mechanism of microplastics and suspended sand in the Three Gorges Reservoir |
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Liu Jie1，2，Zhang Zhichao1，2，Li Xia1，2，Zhu Lifan1，2，Jiang Hui1，2
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1.National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing 400074 , P.R.China ；2.College of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074 , P.R.China
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| Abstract: |
| A custom-built large-scale flume was utilized to conduct heterogeneous aggregation experiments between microplastics and sediment under the influence of shear flow, and thus to analyze their morphological characteristics and aggregation mechanisms. Two typical types of microplastics (PMMA and PS) in the upper Yangtze River were selected for our investigation. The sediment sample configuration was determined based on the mineral composition and the grading of the suspended sediment in the Three Gorges Reservoir backwater area. The results showed that under turbulent shear flow, the particle size of flocs formed by the heterogeneous aggregation of microplastics and sediment was larger than that of flocs formed by homogeneous sediment aggregation. The number of microplastics adsorbed on microplastic-sediment flocs per milliliter of sample increased rapidly with the increase in shear rate of the water flow. The results of scanning electron microscopy and energy dispersive spectroscopy analyses showed that heterogeneous aggregation of sediment with the PMMA and PS occurred under hydrodynamic conditions. During aggregation, electron transfer and shifts in chemical states occurred, leading to the formation of unsaturated bonds (C C). The variation in the binding energy of PMMA functional groups was greater than that of PS. This suggests that PMMA lost more electrons in this process, resulting in a higher surface charge and propensity increase to aggregate with sediment. |
| Key words: Microplastic suspended sediment microplastics-sediment flocs shape aggregation mechanism Three Gorges Reservoir |
