Evaluation of a Water Treatment System for Removing Microplastic in an Aqueous Media

Objective: The objective of this study is to investigate the efficiency of a hybrid system composed of a Bradley-type hydrocyclone with a sand filter and a polymeric microfiltration membrane for the purpose of removing microplastics in an aqueous medium. Theoretical Framework: The studies highlight the principles of hydrodynamic separation in hydrocyclones, filtration mechanisms in granular media, such as sand filters, and membrane separation processes, specifically microfiltration. Furthermore, mass balance equations are considered to determine microplastic removal efficiency, based on solid-liquid separation models. The study is also based on the guidelines of Ordinance GM/MS N°888/2021 for water quality parameters and on the analytical methods established by the Standard Methods for the Examination of Water and Wastewater (APHA/AWWA/WEF, 2023), providing a solid basis for understanding the context of the investigation. Method: The system was characterized for four operating pressures (0.5 to 2.0 bar), analyzing variables such as pressure and flow. Experiments were conducted with microplastic suspension (1.0 g/L) under agitation, collecting samples at six points in the system every 5 minutes. The analyzes considered color, turbidity and concentration, following APHA standards and Ordinance GM/MS N°888/2021. The concentration of microplastics was determined by vacuum filtration and weighing after drying. Results and Discussion: The hydrocyclone operated efficiently, reducing the concentration of microplastics depending on the operating pressure, with a maximum removal of 100% at 1.5 bar. Pressures between 0.5 and 1.5 bar showed better underflow performance, while at 2.0 bar the efficiency was lower. The sand filter showed high effectiveness, varying between 90% and 100%, and the microfiltration membrane achieved 100% microplastic removal, with total recovery of 70%, demonstrating the system's efficiency in water treatment. Research Implications: This research contributes to water treatment by demonstrating the efficiency of a hybrid system in removing microplastics without chemical reagents. Its results can influence sustainable technologies, environmental policies and the improvement of water quality in sanitation and industries. Originality/Value: This study is innovative in evaluating the removal of microplastics with a hybrid system of hydrocyclone, sand filter and microfiltration, without chemical reagents. Its relevance lies in offering an efficient and sustainable solution for water treatment, contributing to environmental preservation and water security.