Source Apportionment and Interaction Between Microplastics and Environmental Pollutants: A Review on Current Understanding and Prognosis

Microplastics (MPs) are a group of pollutants made of a complex mix of chemicals and polymers found in a wide range of ecosystems. Heavy metals and organic pollutants have also been proven to affect the ecosystem in many ways. The cumulative impact of MPs and other organic and inorganic contaminants poses a significant environmental threat. The present chapter aims to understand the interaction of organic and inorganic contaminants with MPs in various environments. The study was carried out by considering articles dealing with the transport and interaction of MPs with organic or inorganic contaminants. The review shows that MP adsorption characteristics change with particle size, surface area, polymer type, and aging. Adsorption is a necessary process governing the interaction of MPs with organic or inorganic pollutants. Organic contaminants adhere to MPs mainly through hydrophobic, π − π interactions, and electrostatic interactions. Inorganic contaminants get adsorbed specifically through π − π interactions and electrostatic interactions. Van der Waals and hydrogen bonding for organic pollutants and ion exchange for inorganic contaminants also play a significant role in interacting these components with MPs. As adsorption is the dominant process, these sites may be preferred by organic and inorganic contaminants simultaneously. A deep understanding of MPs’ interactions with organic and inorganic pollutants will help to enhance understanding of the processes governing the settling or releasing of these contaminants from MPs. This will also help to improve the management techniques for reducing the environmental impacts of these contaminants in the future.