Microplastics in rainwater/stormwater environments: Influencing factors, sources, transport, fate, and removal techniques

Microplastics (MPs) in rainwater/stormwater environments pose significant threats to the aquatic environment. This study presents a comprehensive review of the abundance, sources, transport, fate, and potential solutions of MPs in these environments. Various factors, including sample types, analytical techniques, target sizes, rainfall characteristics, geographical locations, and land use, influence the abundance and characteristics of MPs. Understanding these factors is crucial for accurately assessing and comparing MPs levels in different studies. Plastic products from daily life and particles generated by tire and road wear are identified as primary sources of MPs in these environments, with rainwater/stormwater acting as conduits for their transport. The fate of MPs is determined by complex processes such as sedimentation, weathering, biofilm formation, and biological degradation. Given the significant impact of MPs on the aquatic environment, their removal from rainwater/stormwater environments is crucial. Techniques like constructed wetlands, bioretention systems, and filtration show promise for MPs removal, but their effectiveness varies depending on factors like size and mobility. Further research is needed to improve replicability and assess the influence of flow rate and rainfall intensity, particularly for the underestimated MPs smaller than 100 mm. & COPY; 2023 Elsevier B.V. All rights reserved.