| 骆马湖表层沉积物微塑料的分布、来源及储存量 |
| 摘要点击 1965 全文点击 575 投稿时间：2021-08-24 修订日期：2021-10-11 |
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| 中文关键词 骆马湖 表层沉积物 微塑料 环境行为 人工泄洪 调水工程 |
| 英文关键词 Luoma Lake surface sediment microplastic environmental behavior artificial flood discharge water transfer |
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| 中文摘要 |
| 为探求骆马湖表层沉积物微塑料的分布特征，于2019年夏季和2021年冬季收集了20个采样点的样品，使用光学显微镜观察微塑料特征并分类，使用傅里叶变换红外显微镜光谱仪鉴定其聚合物成分，使用扫描电子显微镜分析其表面形态.结果表明，骆马湖夏季和冬季沉积物微塑料的丰度平均值为（513±201） n ·kg-1和（528±263） n ·kg-1.总体而言，60~500 μm、纤维、透明和聚乙烯微塑料占比最高，表层沉积物微塑料的储存量分别为111.20 t （9月）和74.16 t （1月）.结果发现，夏季人工泄洪后，闸后小尺寸微塑料的比例均高于闸前30%以上，证明水流剪切力是加速微塑料破碎的驱动力.开始调水后，上游的微塑料丰度平均值从705 n ·kg-1下降到653 n ·kg-1，而下游则从530 n ·kg-1增加到740 n ·kg-1.上游沉积物中消失的是较小和较轻的塑料颗粒，如聚乙烯和聚丙烯.它们随着水流在上游表层沉积物中再悬浮，迁移至下游，并再次沉降.通过探讨人工泄洪和调水对蓄水湖表层沉积物微塑料分布的影响，为人工调控下微塑料的环境行为提供新的证据. |
| 英文摘要 |
| In the summer of 2019 and the winter of 2021, surface sediments from 20 sampling sites were collected from Luoma Lake. An optical microscope was used to observe and classify the microplastics. A microscope Fourier transform infrared spectrometer was used to identify the polymer composition, and a field emission scanning electron microscope was used to analyze the surface morphology. The results showed that the average abundances of microplastics in Luoma Lake sediments were (513±201) n·kg-1 and (528±263) n·kg-1. Overall, 60-500 μm fiber, transparent, and polyethylene microplastics accounted for the highest proportion. The storages of surface sediment microplastics were 111.20 t (September) and 74.16 t (January). After the artificial flood discharge, the proportion of small-sized microplastics behind the sluice was over 30% higher than that in front of the sluice, showing that hydrodynamic shear stress was the driver accelerating microplastic degradation. The average abundance of microplastics upstream of the water transfer route decreased from 705 n·kg-1 to 653 n·kg-1 after the water transfer, whereas the downstream increased from 530 n·kg-1 to 740 n·kg-1. According to the microscope observation and polymer identification, the disappeared microplastics upstream were the smaller particles and lighter polymers like polyethylene and polypropylene. They resuspended from the surface sediments with the current, migrated from upstream to downstream, and resettled. The effects of artificial flood discharge and water transfer on the distribution of microplastics in the surface sediments of the impounded lake were investigated, providing new evidence for the environmental behavior of microplastics under artificial regulation. |
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