Progress in the Study on Ageing Behavior of Microplastics and Its Effect on Heavy Metal Adsorption

Microplastics are regarded as the ideal carriers of pollutants present in the environment due to their small particle size, large specific surface area and high hydrophobicity. At present, microplastic pollution has become a health concern worldwide. Microplastics are commonly found in water, soil and the atmosphere, the concentration of which varies from region to region. The microplastics existing in the environment are often subject to ageing effects due to solar irradiation, oxidation and mechanical wear, which causes change to their physicochemical properties and triggers their interaction with pollutants. As for the current research on microplastic-pollutant interactions, it focuses on organic pollutants, and the researches on exploring the ageing behaviour of microplastics, its effect on heavy metal adsorption and the mechanisms behind it are just in the initial stage. An overview of the current status of research on microplastic ageing, including surface changes, functional group changes, crystallinity changes and release of plastic additives before and after ageing. Besides, the progress made in studying the effects of ageing microplastics on heavy metal adsorption and its mechanisms are explored. On this basis, the future directions of research are indicated. It is expected to provide a practical reference for fully understanding the current status of research on microplastics and its future directions.