南淝河中微塑料的分布特征及来源

目的] 研究流经城市河流中微塑料的污染情况，探索水体微塑料来源，旨在为微塑料污染防控积累基础资料，并为控制和治理提供科学依据。方法] 于2019年3月份采集安徽省合肥市南淝河水和沉积物样，通过密度浮选、体式显微镜与傅里叶红外光谱仪等研究了微塑料的分布特征及其来源规律。结果] 南淝河水和沉积物样品中普遍存在发泡、纤维、颗粒和碎片4类的微塑料颗粒，丰度分布规律基本一致，均集中在河流中游、人口密集段，表明河流中微塑料残留受人为影响较大。在水与沉积物中，微塑料粒径分布都表现出随着微塑料粒径增大，含量随之减少的规律；纤维类微塑料占比最大，泡沫类微塑料占比最少，表明其主要来源于人们的日常活动与污水处理厂的排放。按颜色分，彩色与透明比例大，黑色与白色占比较少。水样中碎片类高于颗粒类，沉积物中相反。傅里叶红外光谱仪分析表明，颗粒类和纤维类微塑料为聚乙烯，碎片类为聚丙烯，发泡类为聚苯乙烯。结论] 微塑料普遍存在河流水体与沉积物中，污染状况处于一个较高水平，主要来源于人们的日常活动与污水处理厂的排放。

Distribution Characteristics and Sources of Microplastics in Nanfei River

Objective] The distribution and sources of microplastic pollution in the Nanfei River as it flows through cities were studied in order to not only accumulate basic data for microplastic pollution prevention, but also provide a scientific basis for the control and treatment of microplastics.Methods] The water and sediment samples from the Nanfei River, located in Hefei City, Anhui Province, were collected during March 2019, and the distribution and sources of microplastics in these samples were studied by density flotation, stereomicroscope identification, and Fourier infrared spectroscopy.Results] Four types of microplastic particles (foams, fibers, particles, and fragments) were common in the water and sediment samples from the Nanfei River. The abundance distribution was basically similar for all types of microplastics, with all types more concentrated in the densely populated middle reaches of the river, indicating that microplastic pollution in the river was greatly affected by human activities. The particle size distribution of microplastics in the water and sediment samples showed that the abundance of microplastics decreased as the particle size increased. Fiber microplastics accounted for the largest proportion of microplastics observed, and foam microplastics accounted for the least, indicating that the microplastics were mainly derived from people''s daily domestic activities and sewage treatment plant discharges. Regarding the color of the microplastics, the largest proportion of microplastics were colored or transparent, whereas black and white microplastics accounted for less. In contrast to sediments, the abundance of microplastic fragments was higher than that of microplastic particles in the water samples. The results of the Fourier infrared spectrometry showed that the particle and fiber microplastics were polyethylene, the fragments were polypropylene, and the foam microplastics were polystyrene.Conclusion] Microplastics were widespread in river water and sediments at high levels, and were mainly derived from people''s daily activities and discharges from sewage treatment plants.