Performance of Conventional Drinking Water Treatment Plants in Removing Microplastics in East Java, Indonesia

Abstract

Microplastic (MP) has been a new emerging contaminant in the municipal water supply. A water treatment process is a key to producing high-quality and safe drinking water. The performance of a conventional drinking water treatment plant (CDWTP) to remove MPs is questionable. This research aimed to investigate the performance of 2 CD-WTPs in East Java in removing MPs. Full-stage treatment in two CDWTPs consisted of intake, pre-sedimentation, coagulation-flocculation, sedimentation, sand filter, and disinfection units. Five L water samples were collected with a grab sampling technique in the sampling points of intake and outlet of each water treatment unit. MP abundance and characteristics in each sample were determined using a Sunshine SZM-45T-B1 stereomicroscope and a Nicolet i10 FTIR spectrophotometer. Total MP removal efficiencies in CDWTPs I and II were 66 and 62%, respectively. The coagulation-flocculation unit performed the highest MP removal efficiencies (56%). The MP with 1-350 μm size achieved lower removal efficiencies (33-53%) than that with 351-<5,000 μm size (53-76%). The removal efficiencies of fiber, fragment, and film in the CDWTPs were 61-65%; 86-100%; and 100%, respectively.