National Reconnaissance Survey of Microplastics in Municipal Wastewater Treatment Plants in Korea

Hee Jin Park, Min Ju Oh, Pil Gon Kim, Gwonbo Kim, Dong Hwan Jeong, Byoung Kyu Ju, Won Seok Lee, Hyen Mi Chung, Hyun Joong Kang, Jung Hwan Kwon

Research output: Contribution to journalArticlepeer-review

95 Citations (Scopus)


Large quantities of microplastics are thought to be emitted to freshwater environments via wastewater treatment plants (WWTPs). To evaluate the occurrence of microplastics in Korean WWTPs, a nationwide study was conducted for the first time in 50 representative WWTPs with large treatment capacities. Grab sampling and laboratory filtration were used for influents, whereas in situ filtration using a custom-made sampling device was used for effluents. The filtrates were pretreated using wet peroxidation and density separation prior to the identification of microplastics with a dissection microscope and Fourier-transform infrared spectroscopy. Pooled analyses of the microplastics revealed that they were predominantly fragment-shaped, and thermoplastics and synthetic fibers were the dominant microplastic materials in WWTPs. The concentration ranged from 10 to 470 L-1 in influents and 0.004 to 0.51 L-1 in effluents. The removal efficiency of microplastics during wastewater treatment was calculated to be 98.7-99.99% in 31 WWTPs. Additionally, WWTPs using advanced phosphorus removal processes exhibited higher removal efficiency than those not implementing such processes. Power-law distribution was successful in describing microplastic particle sizes down to 100 μm, although it was not applicable for smaller particles. This comprehensive monitoring study provides information on the current level and characteristics of microplastics in WWTPs in Korea.

Original languageEnglish
Pages (from-to)1503-1512
Number of pages10
JournalEnvironmental Science and Technology
Issue number3
Publication statusPublished - 2020 Feb 4

Bibliographical note

Funding Information:
Authors thank Prof. Seung-Kyu Kim and Dr. Jaehak Jung for their comments on this study. This work was supported by a grant from the National Institute of Environmental Research (NIER), funded by the Ministry of Environment of the Republic of Korea (NIER-2018-04-02-038). The authors also thank Editage ( ) for providing English language editing guidance.

Publisher Copyright:
Copyright © 2020 American Chemical Society.

ASJC Scopus subject areas

  • General Chemistry
  • Environmental Chemistry


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