Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing, 400044, China; Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China; Lingzhi Environmental Protection Co., Ltd, Wuxi, 214200, China.
Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing, 400044, China.
Environ Pollut. 2020 Oct;265(Pt A):115033. doi: 10.1016/j.envpol.2020.115033. Epub 2020 Jun 17.
As inland freshwaters act as a major transport pathway for marine microplastic pollution, microplastic pollution in freshwater systems has recently received growing attention. However, the role of environmental and spatial factors in shaping the distribution and characteristics of microplastic pollution in reservoir ecosystems is not well understood. Here, we studied microplastic pollution in the surface water of the Yulin River, a typical tributary of the upper reaches of the Three Gorges Reservoir (TGR). The abundance of microplastics were 1.30 × 10, 1.95 × 10 and 3.60 × 10 items/L in the mainstream, tributaries and bays of the Yulin River, respectively. Polyethylene, polypropylene, and polystyrene were identified as the predominant types. The most common shapes were line/fiber and foam. Small-sized particles dominated the collected microplastics. Aged surface was identified by scanning electron microscopy and X-ray photoelectron spectroscopy. The microplastics in the Yulin River were largely of secondary origin. Microplastic pollution varied in space. The abundance of microplastic was higher upstream reaches than downstream, which was correlated with anthropogenic activity. The backwater of the TGR increased the abundance of microplastic in the estuary of the Yulin River. The abundance of microplastic was negatively correlated with the channel width. This study is helpful for understanding the characterics and distribution of microplastics in reservoir ecosystems within underdeveloped area, and can thereby inform well-directed strategies to mitigate microplastic pollution.
作为内陆淡水的主要运输途径，海洋微塑料污染已引起人们的广泛关注。然而，环境和空间因素在塑造水库生态系统中微塑料污染的分布和特征方面的作用还不太清楚。本研究以三峡库区上游典型支流——御临河表层水体为研究对象，探讨了水库型河流中微塑料污染的分布特征。结果表明，御临河干流、支流和河湾的微塑料丰度分别为 1.30×101.95×103.60×10~3 个/L，以聚乙烯、聚丙烯和聚苯乙烯为主，主要形态为线状/纤维状和块状/泡沫状，以小粒径颗粒为主。扫描电子显微镜和 X 射线光电子能谱分析表明，御临河微塑料多具有老化表面，主要来源于二次源。微塑料污染在空间上存在差异，上游的微塑料丰度高于下游，这与人为活动有关。三峡水库回水增加了御临河河口的微塑料丰度。微塑料丰度与河道宽度呈负相关。本研究有助于了解欠发达地区水库生态系统中微塑料的特征和分布，为制定有针对性的微塑料污染缓解策略提供信息。
