Microplastic (MP) is an emerging pollutant that has attracted attention in the environmental field, and the research of MPs in freshwater systems needs to be strengthened. To characterize the MPs in surface water and sediments of the western urban river network, water and sediment samples were collected. The results showed that the abundance of MPs in the water body of the river network ranged from 7 to 172 n/L, whereas the abundance of MPs in the sediments ranged from 7 to 144 n/kg, and the average abundance in the dry season was significantly higher than that in the rainy season. The majority of MPs (83.67 %) were < 1 mm and fibrous. The most commonly identified types of MPs were PET and PP, while the color blue was frequently observed. MPs have the potential to vertically migrate in sediments, with size, shape, density, and hydrodynamic forces being the main factors that contribute to this process. Correlation analysis results revealed that anthropogenic and meteorological factors, including precipitation, atmospheric conditions, and population density, had a discernible impact on the abundance, size, and shape of MPs. The ecological risk of MPs was assessed using the Polymer Hazardous Index (PHI), Pollution Load Index (PLI), and Potential Ecological Risk Index (PERI) methods, and the results showed that the overall ecological risk of the Lanzhou section of the Yellow River was low. This study can provide a scientific basis for monitoring and risk assessment of emerging contaminants such as MPs in the river environment.

中文翻译：

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黄河兰州段微塑料分布特征、生态风险评价及影响因素分析


微塑料（MP）是一种引起环境领域关注的新兴污染物，淡水系统中MP的研究有待加强。为了表征西部城市河网地表水和沉积物中的 MP，收集了水和沉积物样品。结果表明，河网水体中MPs丰度为7～172n/L，沉积物中MPs丰度为7～144n/kg，旱季平均丰度为明显高于雨季。大多数 MP（83.67%）为 < 1 mm 和纤维状。最常见的 MP 类型是 PET 和 PP，而蓝色是最常见的。 MP 具有在沉积物中垂直迁移的潜力，其大小、形状、密度和水动力是促成这一过程的主要因素。相关分析结果表明，人为和气象因素，包括降水、大气条件和人口密度，对MP的丰度、大小和形状有明显的影响。采用聚合物危害指数（PHI）、污染负荷指数（PLI）和潜在生态风险指数（PERI）等方法对MPs进行生态风险评估，结果表明黄河兰州段总体生态风险很低。该研究可为河流环境中MP等新兴污染物的监测和风险评估提供科学依据。