Comparative Removal Efficiency of Polypropylene Microplastics from Aqueous Solutions by Filtration, Centrifugation, and Flocculation

Microplastics, which decompose from large pieces of plastic and cause water pollution, are becoming an increasing environmental problem due to their stable structure, high mobility, and ease of interaction with organic compounds in the environment. Large amounts of microplastics enter surface waters through wastewater and stormwater. Therefore, it is necessary to develop simple and accessible methodologies as a foundation for establishing reliable and effective strategies for microplastic removal from aquatic environmental samples. In this study, the removal of microplastics (< 1 mm) at laboratory scale using synthetic microplastics is investigated by three methods: filtration, centrifugation and flocculation. For this purpose, polypropylene-based microplastic particles are prepared and turbidity is used to measure removal. In this study, all three methods are investigated to determine a more effective method for the removal of microplastic particles. Among the three methods studied, the centrifuge method showed higher removal efficiency than the filtration and flocculation methods for the removal of microplastic particles from aqueous solution. The removal efficiency of microplastic particles by the centrifugation method reached 95.6% and was 90.6% by the filtration method. The flocculation method has a lower removal efficiency of microplastic particles than the centrifugation and filtration methods, ranging from 75.6 to 81.8%. In general, the results show that centrifugation is the more suitable and efficient method to remove microplastic particles from aqueous solution.