Identification of microplastics and their removal efficiency in drinking water treatment plants in tropical areas: a case study of the Dago Pakar drinking water treatment plant, Bandung, Indonesia

ABSTRACT This study investigates microplastic (MP) concentrations, characteristics, and removal efficiency in different treatment units of drinking water treatment plants (DWTPs) at different seasons and sampling times. The result shows that MP levels were higher during the rainy season compared to the dry season. Based on statistical analysis, there are significant differences and correlations between the number of MPs in the water and the seasonal variations of sampling times. Furthermore, even though the number of MPs was slightly higher in the morning compared to the other times, there were no significant differences or correlations between the MPs and the sampling times. The MP size was dominated by the size of 300–1,000 μm (88 and 96% for rainy and dry seasons, respectively) while fibre and transparent are the dominant shape and colours of MPs. The dominant polymer types found were polyester and polyethylene terephthalate. The average removal efficiencies of MPs by Dago Pakar DWTP in the rainy and dry seasons were 58.9 and 39.3%, respectively. Based on these results, it can be seen that the Dago Pakar DWTP has not significantly removed the MPs contained in the raw water source thus a post-treatment unit is needed.