Chen Sheng-Sheng, Li Wei-Ming, Zhang Kun, Xiong Wei-Wei, Zhang Xu-Tong, Liu Zi-Jian
Hubei Field Observation and Scientific Research Stations for Water Ecosystem in Three Gorges Reservoir, Yichang 443002, China.
College of Hydraulic and Environmental Engineering, China Three Gorges University, Yichang 443002, China.
Huan Jing Ke Xue. 2022 Jun 8;43(6):3077-3087. doi: 10.13227/j.hjkx.202109268.
Microplastics as a prevalent pollutant in water bodies have recently attracted widespread attention. To investigate the spatial and temporal distribution characteristics of microplastics in freshwater rivers and their migration patterns, the surface water, sediments, and subsidence zone of the Xiangxi River, a tributary of the Yangtze River, were sampled and analyzed in November 2020 and April 2021, respectively. The results showed that the average abundance of microplastics in the surface water of Xiangxi River was (6.64±1.32) n·L in flat water and (5.00±1.07) n·L in dry water, the average abundance of microplastics in sediments was (0.56±0.13) n·g in flat water and (0.41±0.09) n·g in dry water, and the average abundance of microplastics in the subsidence zone was (0.53±0.15) n·g in flat water and (0.68±0.18) n·gin dry water. There were significant differences in the abundance distribution of microplastics in the surface water, sediments, and subsidence zone (<0.05). In the surface water and sediments, the particle size of microplastics was mainly distributed in the range of 0.1-0.5 mm, and in the subsidence zone, it mainly ranged from 1-5 mm. The color of microplastics was mainly transparent in the surface water and subsidence zone and blue in sediments. The morphology of microplastics in the Xiangxi River basin was mainly fiber, and the materials were mainly polyethylene (PE) and polypropylene (PP). There were many factors affecting the distribution of microplastics. The analysis results showed that the abundance of microplastics in the surface water was negatively correlated with the flow rate of the water body. The abundance of microplastics in the sediment was related to the substrate type of the riverbed and negatively correlated with the substrate particle size. Combined with the microplastic abundance data of each sampling site, it was found that there was a significant migration process of microplastics in the spatial distribution of the Xiangxi River in the watershed. Along the river longitudinal direction, the longitudinal migration of microplastics in the surface water was along the river direction, and in the vertical direction, it showed the mutual migration between the water body and the subsidence zone and the water body and sediments.
微塑料作为水体中一种普遍存在的污染物，最近引起了广泛关注。为了研究淡水河流中微塑料的时空分布特征及其迁移模式，分别于2020年11月和2021年4月对长江支流香溪河的地表水、沉积物和沉降区进行了采样和分析。结果表明，香溪河平水期地表水微塑料平均丰度为(6.64±1.32)个/升，枯水期为(5.00±1.07)个/升；沉积物平水期微塑料平均丰度为(0.56±0.13)个/克，枯水期为(0.41±0.09)个/克；沉降区平水期微塑料平均丰度为(0.53±0.15)个/克，枯水期为(0.68±0.18)个/克。地表水、沉积物和沉降区微塑料丰度分布存在显著差异(<0.05)。地表水和沉积物中微塑料粒径主要分布在0.1 - 0.5毫米范围内，沉降区主要分布在1 - 5毫米范围内。地表水和沉降区微塑料颜色主要为透明，沉积物中主要为蓝色。香溪河流域微塑料形态主要为纤维状，材质主要为聚乙烯(PE)和聚丙烯(PP)。影响微塑料分布的因素较多。分析结果表明，地表水微塑料丰度与水体流速呈负相关。沉积物中微塑料丰度与河床底质类型有关，与底质粒径呈负相关。结合各采样点微塑料丰度数据，发现香溪河流域空间分布中存在明显的微塑料迁移过程。沿河流纵向，地表水微塑料纵向迁移沿河流方向，在垂直方向上，表现为水体与沉降区、水体与沉积物之间的相互迁移。
