玛瑙河多环境介质和铜锈环棱螺体内微塑料的赋存特征

Occurrence Characteristics of Microplastics in Multi-environmental Media and Bellamya aeruginosa of Manao River

微塑料污染对水生态系统及人类健康危害大,为探究微塑料在不同环境介质中的赋存特征,选择长江一级支流玛瑙河为研究区域,通过现场采样、显微镜观察和傅里叶红外光谱测定等,对玛瑙河表层水体、沉积物、河岸带土壤和底栖动物铜锈环棱螺中微塑料的丰度、粒径、形状、颜色和组成类型进行了分析.结果表明,玛瑙河表层水体的微塑料平均丰度为(5.9±0.26)n·L^(-1);上层沉积物中微塑料丰度(以干重计)为(1.35±0.1)n·g^(-1),下层沉积物中微塑料丰度(以干重计)为(0.93±0.12)n·g^(-1);近河岸带土壤中微塑料丰度(以干重计)为(0.68±0.16)n·g^(-1),远河岸带土壤中微塑料丰度(以干重计)为(0.69±0.14)n·g^(-1);铜锈环棱螺体内微塑料丰度为(2.06±0.25)n·g^(-1).分析发现,上层沉积物和下层沉积物中微塑料丰度呈正相关;铜锈环棱螺体内微塑料丰度分别与上、下层沉积物中微塑料丰度呈正相关;近、远河岸带土壤中微塑料丰度具有相关性.各环境介质和铜锈环棱螺体内微塑料粒径大多<0.1mm,主要形态为纤维状和碎片状,颜色以蓝色和黑色为主,成分主要是聚丙烯(PP)和聚乙烯(PE).研究发现,河岸带土壤中微塑料主要来源于农用塑料薄膜的破碎和分解.通过多环境介质调查和铜锈环棱螺体内微塑料的分析,探明了大型底栖动物体内微塑料的累积效应,可为全面了解微塑料潜在生态风险提供依据.

Microplastic pollution poses threats to aquatic ecosystems and human health.In this study,in order to investigate the characteristics of microplastic occurrence in different environmental media,the abundance,particle size,shape,color,and composition types of microplastics in the water column,sediment,riparian zone soil,and the benthic snail Bellamya aeruginosa of the Manao River were analyzed using field sampling,microscopic observation,and Fourier infrared spectroscopy.The results showed that the average abundance of microplastics in the surface water of the Manao River was(5.9±0.26)n·L^(−1);the abundance of microplastics in the upper sediment(by dry weight)was(1.35±0.1)n·g^(−1),and that in the lower sediment(by dry weight)was(0.93±0.12)n·g^(−1).The abundance of microplastics in the near riparian zone soil(by dry weight)was(0.68±0.16)n·g^(−1),and that in the far riparian zone soil(by dry weight)was(0.69±0.14)n·g^(−1),and the abundance of microplastics in the B.aeruginosa was(2.06±0.25)n·g^(−1).The analysis results showed that the abundance of microplastics in the upper and lower sediments were positively correlated;the abundance of microplastics in B.aeruginosa was positively correlated with the abundance of microplastics in the upper and lower sediments,respectively;and the abundance of microplastics in the near and far riparian zone soils were also correlated.Most of the microplastics within each environmental medium and B.aeruginosa were<0.1 mm in size,mainly in the form of fibers and fragments,mainly blue and black in color,and mainly composed of polypropylene(PP)and polyethylene(PE).It was found that microplastics in riparian zone soils mainly originated from the fragmentation and decomposition of agricultural plastic films.The results of this study shed light on the accumulation of microplastics in macrobenthic organisms through the investigation of microplastics in multi-environmental media and in the B.aeruginosa,which helps us to understand the potential ecological risk of microplastics in a comprehensive manner.