Tracing microplastics from raw water to drinking water treatment plants in Busan, South Korea Jae-Won Jung a , Siyoung Kim a , Yong-Soon Kim a , Sanghyun Jeong b , Jieun Lee c, ⁎ a Water quality research institute, Busan Water Authority, Busan 47210, South Korea b Department of Environmental Engineering, Pusan National University, Busan 46241, South Korea c Institute for Environment and Energy, Pusan National University, Busan 46241, South Korea HIGHLIGHTS • MPs abundance in raw water and drink- ing water treatment plant in Korea was investigated. • MPs abundance in river and lake changed irregularly over the seasons. • No distinct differences in MPs sizes and types were observed between river and lake. • Mn concentration has positive correlation with MPs amounts in river water. • Most of MPs in raw water were removed during the drinking water treatment process. GRAPHICAL ABSTRACT ABSTRACT ARTICLE INFO Article history: Received 2 November 2021 Received in revised form 14 February 2022 Accepted 15 February 2022 Available online 19 February 2022 Editor: Dimitra A Lambropoulou The increasing amount of plastic waste has raised concerns about microplastics (MPs) in aquatic environments. MPs can be fragmented into nanoplastics that can pass through water treatment processes and into tap water; potentially threatening human health because of their high adsorption capacity for hazardous organic materials and their intrinsic toxicity. This case study investigates the identification, fate, and removal efficiency of MPs in Korean drinking water treatment plants. Two sites on the Nakdong River, two lake reservoirs (raw water sources), and four corresponding drinking water treatment plants were targeted to trace the amounts, types, and sizes of MPs throughout the treatment process. Monthly quantitative and qualitative analyses were conducted by chemical image mapping using micro- Fourier-transform infrared spectroscopy. MPs larger than 20 μm were detected, and their sizes and types were quan- tified using siMPle software. Overall, the number of MPs in the river sites (January to April and October to November) exceeded those in the reservoirs, but only slight differences in the number of MPs between rivers and lake reservoirs were detected from June to October. The annual average number of MPs in River A, B and Lack C and D was not dis- tinctively different (2.65, 2.48, 2.46 and 1.87 particles/L, respectively). The majority of MPs found in raw waters were polyethylene (PE)/polypropylene (PP) (> 60%) and polyethylene terephthalate (PET)/poly(methyl methacrylate) (PMMA) (20%), in addition to polyamide (<10%) in the river and polystyrene (<10%) in the lake reservoirs. Approx- imately 70–80% of the MPs were removed by pre-ozonation/sedimentation; 81–88% of PE/PP was removed by this process. PET/PMMA was removed by filtration. Correlation of MPs with water quality parameters showed that the Keywords: Microplastics Fourier-transform infrared spectroscopy Drinking water treatment plant Polyethylene Polyethylene terephthalate Science of the Total Environment 825 (2022) 154015 Abbreviations: ABS, acrylonitrile butadiene styrene; DWTPs, drinking water treatment plants; FPA, focal plane array; FTIR, Fourier-transform infrared; ICP-MS, inductively coupled plasma-mass spectrometry; MPs, microplastics; NPs, nanoplastics; PA, Polyamide; PAEs, phthalate esters; PC, polycarbonate; PCBs, polychlorinated biphenyls; PE, polyethene; PET, polyethene terephthalate; PMMA, poly(methyl methacrylate); PP, polypropylene; PS, polystyrene; PVC-u, unplasticised polyvinyl chloride; SEM, scanning electron microscopy; TOC, total organic carbon; UV, ultraviolet; WWTPs, wastewater treatment plants. ⁎ Corresponding author. E-mail address: 99atkins07@gmail.com (J. Lee). http://dx.doi.org/10.1016/j.scitotenv.2022.154015 0048-9697/© 2022 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv