Fate and behavior of microplastics in wastewater, accumulation in organisms and effects

Abstract Studies on how microplastics (MPs) behave in wastewater treatment plants (WWTPs) are increasing day by day. Although conventional WWTPs can efficiently remove MPs (64–99%), when considering the daily discharge rate, this percentage would not be sufficient. The total amount of MPs would still be discharged daily into the environment; therefore, the final effluent can act as one of the main routes of entry of MPs into aquatic environments. This chapter reviews the behavior of MPs in the different WWTP units, as well as their accumulation in the sludge. Subsequently, a discussion on how the MPs from the WWTP can reach the receiving media, such as aquatic or terrestrial media (water line and sludge line), to finally discuss how the fauna is affected by the entry of the MPs into the environment. These MPs can be ingested by aquatic life forms, leading to their bioaccumulation and biomagnification along the food chain, and causing negative effects on tissues, organs, and metabolism. MPs can also act as transport vehicles for other emerging pollutants such as pharmaceuticals and pesticides, increasing their hazardousness.