Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
Sci Total Environ. 2021 Mar 1;758:143633. doi: 10.1016/j.scitotenv.2020.143633. Epub 2020 Nov 12.
The source, distribution, migration, and fate of microplastics (MPs) in aquatic and terrestrial ecosystems have received much attention. However, the relevant reports in wetland ecosystems, the boundary area between water and land, are still rare. Where are the sources and sinks of MPs in the wetland? The latest researches have shown that the sources of MPs in wetlands include sewage discharge, surface runoff, and plastic wastes from aquaculture. Fibers and fragments are the most common shapes, and PE, PP, PS can be detected in water or sediment matrices, and biota of wetlands. The distribution is affected by hydrodynamic conditions, sediment properties, and vegetation coverage. Factors affecting the vertical migration of MPs include their own physical and chemical properties, the combination of substances that accelerate deposition (mineral adsorption and biological flocculation), and resuspension. Minerals tend to adsorb negatively charged MPs while algae aggregates have a preference for positively charged MPs. The wetlands vegetation can trap MPs and affect their migration. In water matrices, MPs are ingested by organisms and integrated into sediments, which makes them seem undetectable in the wetland ecosystem. Photodegradation and microbial degradation can further reduce the MPs in size. Although recent research has increased, we are still searching for a methodological harmonization of the detection practices and exploring the migration rules and fate patterns of MPs. Our work is the first comprehensive review of the source, distribution, migration, and fate of MPs in wetland ecosystems. It reveals the uniqueness of wetland habitat in the research of MPs and indicates the potential of wetlands acting as sources or sinks for MPs.
微塑料（MPs）在水生和陆地生态系统中的来源、分布、迁移和归宿受到了广泛关注。然而，在湿地生态系统（水-陆交界带）中，相关报道仍然很少。湿地中 MPs 的源和汇在哪里？最新研究表明，湿地中 MPs 的来源包括污水排放、地表径流和水产养殖中的塑料废物。纤维和碎片是最常见的形状，PE、PP、PS 可以在水或沉积物基质以及湿地生物群中检测到。分布受水动力条件、沉积物特性和植被覆盖的影响。影响 MPs 垂直迁移的因素包括其自身的物理化学性质、促进沉积的物质的结合（矿物吸附和生物絮凝）以及再悬浮。矿物质倾向于吸附带负电荷的 MPs，而藻类聚集体则对带正电荷的 MPs 有偏好。湿地植被可以捕获 MPs 并影响它们的迁移。在水基质中，MPs 被生物体摄取并整合到沉积物中，这使得它们在湿地生态系统中似乎无法检测到。光降解和微生物降解可以进一步减小 MPs 的尺寸。尽管最近的研究有所增加，但我们仍在寻找检测实践的方法学协调，并探索 MPs 的迁移规律和归宿模式。我们的工作是对湿地生态系统中 MPs 的来源、分布、迁移和归宿的首次全面综述。它揭示了湿地生境在 MPs 研究中的独特性，并表明湿地作为 MPs 的源或汇的潜力。
