渭河微塑料污染现状与风险评价

为探究西北地区渭河微塑料的赋存状态、形态特征、聚合物类型和潜在风险，于2021年5月通过现场采样、显微镜观察、傅里叶红外光谱和显微拉曼光谱测定等，鉴定了渭河水体中的微塑料的丰度分布、形状、粒径、颜色和聚合物类型，并通过污染负荷指数法和物种敏感性分布法进行风险评价.结果表明，所有采样点均有微塑料存在，其丰度范围为(2.9±0.8)～(10.3±2.8)n·L^-1,渭河干流微塑料丰度高于支流.纤维(15.04%～77.03%)、小尺寸(<0.5 mm)(27.27%～89.38%)和彩色(有色)(15.85%～49.53%)为含量最高的微塑料形态，聚乙烯(32.83%)、聚丙烯(29.79%)、聚苯乙烯(21.21%)和聚对苯二甲酸乙二醇酯(10.61%)是检测出的主要聚合物类型.研究表明，渭河微塑料污染处于国内中等水平，微塑料丰度还未对水生生物构成影响，但其较高的丰度值和塑料易吸附其他污染物的特性仍需引起警惕.

Microplastic Pollution Status and Ecological Risk Evaluation in Weihe River

This study aimed to explore the occurrence state, morphological characteristics, polymer types, as well as potential ecology of microplastics in the Weihe River in Northwest China. Thus, we identified the abundance distribution, shape, particle size, color, and polymer type of microplastics in the surface water of the Weihe River by conducting field sampling, microscope observation, Fourier infrared spectroscopy, Micro-Raman spectroscopy, etc., during the normal water period (May) of 2021. Subsequently, we analyzed the potential ecological and environmental risks of microplastics using the pollution load index method and species sensitivity distribution method. The results showed that microplastics were detected to exist in all sampling points and the abundance ranged from (2.9±0.8) to (10.3±2.8) n·L^-1. The concentration of microplastics in the main stream of the Weihe River was higher than that in the tributaries. Fiber (15.04%-77.03%), small size (<0.5 mm) (27.27%-89.38%), and colored (15.85%-49.53%) were the predominant microplastic types. Polyethylene (32.98%), polypropylene (29.79%), polystyrene (21.21%), and polyethylene (10.61%) terephthalate were the main types of polymers detected. In general, the microplastic pollution in Weihe River was at a medium level and had not affected aquatic organisms, but its high concentration and the characteristic of the plastics to adsorb other pollutants are still of concern.