Occurrence and fate of microplastics at two different drinking water treatment plants within a river catchment

Microplastics (MPs) are emerging globally distributed pollutants of aquatic environments, and little is known about their fate at drinking water treatment plants (DWTPs), which provide a barrier preventing MPs from entering water for human consumption. This study investigated MPs 0.02%) of all detected particles at both DWTPs. With regard to size and shape of MPs, the majority (70%) were smaller than 10 mu m, and only fragments and fibres were found, while fragments clearly prevailed. The most frequently occurring materials were cellulose acetate, polyethylene terephthalate, polyvinyl chloride, polyethylene, and polypropylene. Much higher total removal of MPs was achieved at the DWTP with a higher initial MP load and more complicated treatment (removal of 88% versus 40%); coagulation-flocculation-sedimentation, deep-bed filtration through clay-based material, and granular activated carbon filtration contributed to MP elimination by 62%, 20%, and 6%, respectively. Additionally, results from this more complex DWTP enabled to observe relationships between the removal efficiency and size and shape of MPs, particularly in the case of the filtration steps. (c) 2020 Elsevier B.V. All rights reserved.