Study of Polyurethane Microplastics Removal from Water Using Smart Instalation

Microplastics, plastic particles smaller than 5 mm in size, have become a contaminant of priority concern in the environment. Microplastic pollution is a significant environmental challenge, highlighting the need for improved water treatment methods. This study investigates the removal of two fractions of polyurethane microplastics ranging in size from smaller than 100 µm, D1, and in range 200 µm - 500 µm, D2, from aqueous synthetic solutions having a concentration of 0.2 g/L, around 175 NTU. In the first stage of the study, tests were performed to identify the optimal doses of efficient reactive agents for microplastic removal, using the classical method: the Jar test. At this stage, attention was directed towards analyzing the variation of turbidity and their removal efficiency in the presence of classical coagulants such as aluminum sulfate, SA, ferrous sulfate, SF, aluminum polychloride, PA; aloe vera flocculant; and activated carbon, CA of the Norit GAC 830 W type. The classical coagulants such as aluminum sulphate, ferrous sulphate have a good efficiency on microplastic removal, which can provide a residual turbidity in range of 6-10 NTU after a retention time of 50 - 60 minutes. In the second stage of the study, the efficiency of smart decantation-filtration system, DFS, was determined. The efficiency of decanter was studied using Response Surface Methodology (RSM) for identification of the mathematical models necessary to evaluate the effects of key process variables: Flow rate (A), Microplastic size (B), and Aluminum sulphate concentration (C) on microplastic removal efficiency. The sedimentation can raise the optimal value of 98.98 % at the outlet of the decanter. Microplastics in D1 and D2 sized synthetic solutions can be removed from contaminated water by decantation and filtration, the efficiency is around maximum permissible limit, MPL, values of 1 NTU.