Preferential accumulation of small (<300 μm) microplastics in the sediments of a coastal plain river network in eastern China

WATER RESEARCH

卷:144

Article

Wang, Zhenfeng¹  Su, Bobo¹  Xu, Xiaoqun²  Di, Di¹  Huang, Hong¹  Mei, Kun¹  Dahlgren, Randy A.^1,3  Zhang, Minghua^1,3  Shang, Xu¹ 

[1] Wenzhou Med Univ, Sch Publ Hlth & Management, Key Lab Watershed Sci & Hlth Zhejiang Prov, Wenzhou 325035, Peoples R China

[2] Second Inst Oceanog SOA, Lab Marine Ecosyst & Biogeochem, Hangzhou 310012, Zhejiang, Peoples R China

[3] Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA

关键词: Microplastics;    Size spectrum;    Sediment;    Coastal plain rivers;    Fate and transport;   

DOI  :  10.1016/j.watres.2018.07.050

来源: Elsevier

【 摘 要 】

Microplastics are a global concern for their threat to marine ecosystems. Recent studies report a lack of smaller microplastics (<300 mu m) in oceans attributed to a loss in ocean. Several hypotheses have been proposed to explain the absence of smaller microplastics, but their fate and transport remain an enigma. Our study recovered high concentrations of microplastics (32947 +/- 15342 items kg(-1) dry sediment) from sediments of a coastal plain river network in eastern China, with the <300 mu m fraction accounting for similar to 85% of total microplastic particles. Microplastic concentrations were generally higher in sediments from tributary streams and streams surrounded by industrial land use. The high variability of microplastics within the watershed indicates that the distribution of microplastics is regulated by several factors, such as distance to source(s), river flow characteristics, buoyancy behavior, degradation, etc. Fragment and foam forms dominated the small microplastics, while fibers were less prevalent in the <300 mu m fraction and more abundant in downstream sites. The dominance of small microplastics in riverine sediments in this study provides a possible mechanism to explain the relative absence of small microplastics in the ocean, and advocates for quantification of the whole size spectrum of microplastics in future studies of riverine microplastic fluxes. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

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