为探究大房郢水库表层水和沉积物中微塑料的污染现状及其差异，通过采样、密度提取、显微镜观察和拉曼光谱仪测定等方法，对大房郢水库中微塑料的丰度、类型、大小、颜色和聚合物类型进行鉴定。结果表明：表层水中微塑料的平均丰度为(18.62 ± 7.12) n·L-1，沉积物中微塑料的平均丰度为(162.00 ± 57.45) n·kg-1；大房郢水库中微塑料类型以纤维、颗粒和微珠为主，沉积物中微珠的占比高于表层水；50 μm～1 mm范围是表层水和沉积物中占比最高的尺寸类型，其在沉积物中(92.62%)的占比要高于表层水中(84.49%)；沉积物中透明(49.22%)和白色(28.41%)微塑料的占比要高于表层水中，沉积物中黑色(18.66%)微塑料的占比要低于表层水(36.24%)；微塑料主要聚合物类型为聚乙烯(PE)、聚苯乙烯(PS)和聚丙烯(PP)；沉积物中(27.47%)的PS占比高于表层水中(23.73%)，而PE和PP在沉积物中的占比低于表层水中。使用污染负荷指数(PLI)评估大房郢水库表层水和沉积物中微塑料的生态风险，结果均表明大房郢水库处于Ⅰ级风险等级，表层水中的微塑料PLI值显著高于沉积物。
To investigate the current status of microplastics (MPs) contamination in the surface water and sediments of the Dafangying Reservoir and its differences, the abundance, type, size, color and polymer type of MPs were identified by sampling, density extraction, microscope observation and Raman spectrometer determination. The results showed that the average abundance of MPs in surface water was (18.62 ± 7.12) n·L-1, and in sediment was (162.00 ± 57.45) n·kg-1; the types of microplastics in the Dafangying Reservoir were mainly fibers, particles and microbeads were the main morphological types of MPs in the Dafangying Reservoir, and the percentage of microbeads in sediment was higher than that in surface water. The size of MPs was mostly dropped into the range of 50 μm -1 mm, within which MPs in the sediment was higher than in the surface water, the highest percentage of microplastics was found in the sediment (92.62%) than in surface water (84.49%); the proportion of transparent (49.22%) and white (28.41%) MPs in the sediments was higher than that in the surface water, while the proportion of black (18.66%) microplastics in the sediment was lower than that in the surface water (36.24%). The main polymer types of microplastics were polyethylene (PE), polystyrene (PS) and polypropylene (PP). The proportion of PS in the sediment (27.47%) was higher than that in the surface water (23.73%), while the proportion of PE and PP in the sediment was lower than that in the surface water. Pollution load index (PLI) was used to evaluate the ecological risk of MPs in the surface water and sediments of the Dafangying Reservoir. The results showed that the MPs pollution was in hazard level Ⅰ, with significantly higher PLI value in the surface water than that in the sediment.