Discharge of Microplastics from Wastewater Treatment Plants

Abstract

Microplastics are discharged into water bodies via the effluent of wastewater treatment plants (WWTPs) and have been detected throughout the aquatic environment. To fully understand the status of microplastics discharged from WWTPs, this chapter focuses on summarizing the whereabouts and the current composition of microplastics from the aspects of microplastic abundances and polymer types in WWTPs effluent, freshwater systems, marine systems, and aquatic organisms. The results show that polyethylene, polypropylene, polyethylene terephthalate, and polystyrene are microplastics commonly found in water bodies. The content of microplastics was positively correlated with population density, and the content and types of microplastics in organisms were closely related to their habitats. Humans may contain large amounts of microplastics in their bodies. Finally, more attention has been called to focus on the size of microplastics and the development of models for their migration and transformation, which are important to further clarify the contamination by microplastics.