Zhao Xin, Chen Hao, Jia Qi-Long, Shen Chen-Si, Zhu Yi, Li Lei, Nie Yun-Han, Ye Jian-Feng
College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
Shanghai Academy of Environmental Sciences, Shanghai 200233, China.
Huan Jing Ke Xue. 2020 Aug 8;41(8):3612-3620. doi: 10.13227/j.hjkx.201912236.
Rivers have been a subject of great concern in recent years as they have been found to be the critical path for the transmission of microplastics from terrestrial land to the ocean. However, the pollution status of microplastics and their behavior in the surface waters and sediments of urban rivers located in different urban areas remain unclear. In this study, 16 samples of surface water and sediment from eight rivers in the central and suburban areas of Shanghai Megacity were obtained and analyzed. High-speed cameras and Fourier transform infrared spectrometers were used to identify the abundance, size, color, shape, type, and other characteristics of microplastics in these samples. The results showed that the average abundance of microplastics in the surface waters of urban rivers in Shanghai Megacity was (7.5±2.8) pieces·L, while the corresponding average abundance in the sediment reached (1575.5±758.4)pieces·kg (wet weight). The abundance of microplastics was found to increase with the decreasing particle diameter. Among which, microplastics with a size of less than 500 μm, as well as the fibrous shape, transparent color, and Polyester composition, have always dominated in the urban rivers in Shanghai megacity. Comparably, microplastics in the sediments were more diverse in their morphology features and polymer compositions. Microplastic pollution in the urban rivers in Shanghai megacity was severe in comparison to that in other urban rivers worldwide. Among various urban rivers, the distribution of microplastics with different morphology features and polymer compositions is greatly influenced by a number of factors including the source (e.g., mainly laundry wastewater, personal care products, and refuse plastic waste), hydrodynamic conditions, and the physical and chemical properties of plastics. Furthermore, the pollution behavior (i.e., source, transmission, and fate) of microplastics occurring in urban rivers is discussed, and the potential impacts of various environmental factors are explained.
近年来，河流一直备受关注，因为它们被发现是微塑料从陆地传输到海洋的关键路径。然而，不同城区城市河流地表水和沉积物中微塑料的污染状况及其行为仍不清楚。本研究采集并分析了上海特大城市中心城区和郊区八条河流的16份地表水和沉积物样本。利用高速摄像机和傅里叶变换红外光谱仪来识别这些样本中微塑料的丰度、尺寸、颜色、形状、类型及其他特征。结果表明，上海特大城市城市河流地表水中微塑料的平均丰度为(7.5±2.8)个·升，而沉积物中相应的平均丰度达到(1575.5±758.4)个·千克（湿重）。发现微塑料的丰度随粒径减小而增加。其中，尺寸小于500μm的微塑料，以及纤维形状、透明颜色和聚酯成分的微塑料，在上海特大城市的城市河流中一直占主导地位。相比之下，沉积物中的微塑料在形态特征和聚合物组成上更加多样。与世界其他城市河流相比，上海特大城市城市河流中的微塑料污染较为严重。在不同的城市河流中，具有不同形态特征和聚合物组成的微塑料分布受到多种因素的极大影响，包括来源（如主要是洗衣废水、个人护理产品和废弃塑料垃圾）、水动力条件以及塑料的物理和化学性质。此外，还讨论了城市河流中微塑料的污染行为（即来源、传输和归宿），并解释了各种环境因素的潜在影响。
