长江中下游典型浅水湖泊表层水体微塑料时空分布特征——以湖北保安湖为例

以湖北保安湖为研究对象,分别于2021年4、7、10月和2022年1月采集表层水样,测定水体中微塑料丰度、粒径、形状、颜色和类型,探究浅水型湖泊表层水体中微塑料的时空分布特征及其影响因素。结果表明,保安湖表层水体微塑料的年平均丰度为(16.20±2.23)items/L。微塑料丰度呈现明显的季节性差异,其中夏季(采样时间7月)平均丰度最低,为(1.40±0.09)items/L。在所有微塑料颗粒中,粒径0.064~1 mm占比最大,为82.57%;黑色和无色微塑料占主导地位,占比分别为36.16%和21.31%;纤维状微塑料分布最广泛,占比达40.01%;聚乙烯(PE)和低密度聚乙烯(LDPE)是最主要的微塑料类型,两者之和占比达46.05%,其次为聚苯乙烯(PS,占比17.2%)、聚对苯二甲酸乙二醇酯(PET,占比8.33%)和聚乙酸乙酯(PVAC,占比8.31%)。统计分析表明,微塑料丰度与湖水水质无显著相关关系。该研究揭示了长江中下游地区典型浅水湖泊微塑料分布现状,为评估类似湖泊微塑料潜在污染风险提供了科学依据。

Spatial and temporal distribution characteristics of microplastics in surface water of typical shallow lake in the middle and lower reaches of Yangtze River: A case study of Lake Baoan, Hubei Province

The surface water was sampled in Lake Baoan of Hubei Province in April, July, October 2021 and January 2022. The abundance, particle size, shape, color and type of microplastics in water sample were analyzed in order to explore the spatial and temporal distribution characteristics of microplastics in surface water of shallow lakes and their influencing factors. The results showed that the annual average abundance of microplastics in the surface water of the lake was (16.20±2.23) items/L. The abundance of microplastics presented obvious seasonal differences with the lowest average abundance level of (1.40±0.09) items/L in summer (sampling time in July). Microplastic particles size in 0.064-1 mm was dominated, accounting for 82.57% among all particles. Black and colorless microplastic particles were the most common ones, with the percentage of 36.16% and 21.31%, respectively. Fiber (40.01%) was the most widely distributed form of microplastics. Polyethylene (PE) and low density-polyethylene (LDPE) were the dominant types of microplastics, accounting for 46.05%, followed by polystyrene (PS, 17.2%), polyethylene terephthalate (PET, 8.33%) and polyvinyl acetate (PVAC, 8.31%). Statistical analysis showed no significant correlation between microplastic abundance and water quality in the lake. This study revealed the distribution status of microplastics in typical shallow lakes in the middle and lower reaches of the Yangtze River, which provided a scientific basis for assessing the potential pollution risks of microplastics in congener lakes.