Research advances of micro/nanoplastics in groundwater: occurrence, environmental impacts and control strategies.

Microplastic pollution in groundwater systems has garnered significant global attention. Understanding the factors and mechanisms that influence microplastic migration in groundwater is crucial for accurately assessing their distribution and environmental risks. As microplastic pollution in groundwater environments is a relatively new area of study, research is still in its early stages. There are limited reports on the abundance, polymer types, sizes, and other characteristics of microplastics in this field. The strong heterogeneity, complexity, and obscurity of the environment present numerous challenges for conducting related research. In this context, this article reviews the sources, distribution characteristics, potential risks, and removal strategies of microplastics in groundwater environments. It also emphasizes the existing knowledge gaps in the sampling processes and the environmental behavior of microplastics in groundwater. It systematically elucidates the factors influencing microplastic migration in groundwater and analyzes the mechanisms that affect this migration. Exploring the transport mechanisms of microplastics in groundwater aquifers is crucial for assessing their potential harm to the ecological environment and for implementing effective measures to combat microplastic pollution. Additionally, to gain a deeper understanding of the transformation behavior and environmental effects of microplastics in groundwater, a systematic summary and analysis of the current research shortcomings and deficiencies regarding microplastics in the groundwater environment will be conducted, along with a discussion of future research directions.