厦门湾海滩微塑料污染特征

以厦门湾6个典型海滩为工作区,分析海滩微塑料的污染特征.结果表明:①厦门湾6个海滩的微塑料丰度数据范围介于(28. 1±9. 4)～(312. 7±35. 2) n·kg~(-1)之间.②厦门湾海滩微塑料分为碎片类、发泡类、薄膜类和纤维类等4种类型.各站位点均以碎片类和发泡类为主,占总数量的80%左右,薄膜类和纤维类所占比例较少.③厦门湾海滩粒径1 mm的微塑料占最大比例,超过60%.粒径为1～3 mm和3～5 mm的微塑料所占比例较小.④通过红外光谱分析,确认厦门湾海滩微塑料碎片类和纤维类的主要成分是聚乙烯,发泡类和薄膜类的主要成分是聚苯乙烯.⑤通过扫描电镜观测,大部分微塑料表面粗糙、凹凸不平,带有明显裂痕.整体而言,厦门湾海滩微塑料污染处于中等偏下的程度,陆源污染是厦门湾海滩微塑料污染的最主要来源.

Microplastic Pollution of the Beaches in Xiamen Bay, China

Microplastics are tiny ubiquitous plastic particles smaller than five millimeters (5 mm) in size. Coastal and bay areas are constantly under continuous and increasing pressure from the activities of humans. Microplastic pollution is now recognized as a great threat to these areas. This study was designed to understand the microplastic pollution of the beaches in Xiamen Bay. The results showed that microplastic abundance was from (28.1±9.4) to (312.7±35.2) n·kg^-1. Four main types of microplastics were identified in Xiamen Bay, including fragments, foams, thin films, and fibers. Of the particles analyzed, over 80% were predominantly microplastic fragments and foam, while the films and fiber microplastics accounted for less than 20% of the particles. Studies on the particle size of microplastics also indicated that the microplastics with particle size less than 1 mm accounted for over 60% of the total microparticles, and the abundance of microplastics trend to decrease with increase in the particle size. Fourier transform infrared spectroscopy analysis demonstrated that the major component of the fragments and fibers was identified as polyethylene, and that of foams and films was identified as polystyrene. The scanning electron microscope studies showed that the microplastics presented obvious signs of cracks. In general, Xiamen Bay beach microplastic pollution is at a lower middle level, and land source pollution is the main source of the microplastic pollution.