Desenvolvimento e avaliação de um sistema de tratamento de águas para remoção de microplástico em um meio aquoso.

Abstract

Currently, the presence of microplastics in aquatic environments, such as rivers, seas, and oceans, has become an urgent environmental issue, with significant impacts on biodiversity and public health. The growing awareness of the importance of removing these pollutants reinforces the need to develop effective and accessible technologies for treating contaminated water. The relevance of this approach lies in its potential contribution to protecting aquatic ecosystems, promoting public health, and advancing water purification technologies, offering a promising and innovative solution to a growing global environmental problem.The objective of this study is to evaluate the performance of a hybrid system composed of a hydrocyclone/polymeric membrane for the separation of microplastics in aqueous media. The methodology was conducted in three (3) stages: Stage (1) involved assembling the hybrid system for microplastic removal; Stage (2) focused on characterizing the hydrocyclone using treated water from the state company of Paraíba; and Stage (3) considered physicochemical parameters such as color, turbidity, and the Silt Density Index (SDI).The third stage involved experiments in which the quantification and concentration of microplastics (MPs) were analyzed, along with parameters such as recovered fraction, total efficiency of the hydrocyclone and sand filter, and membrane recovery. In the final phase, the influence of MP variation—including PVC, acrylic, and a mixture of PE + acrylic + PVC—was evaluated, highlighting density as a fundamental parameter in analyzing system efficiency.Throughout the experiment, the best system performance was observed at 1.5 bar, with a 28.57% recovery rate and a permeate flow rate of 17.00 L/min. The Silt Density Index (SDI) decreased after treatment. The results of filtration with the sand filter and permeate showed significant microplastic removal, with notable reductions in color and turbidity at the end of the process.In the final phase, PVC separation was the most consistent over time, with the highest recovery in the overflow, while acrylic showed a progressive increase in separation up to 20 minutes of operation. Meanwhile, the PE, AC, and PVC mixture exhibited unstable behavior, possibly due to interactions between polymers of different densities, requiring greater operational control.The microfiltration membrane proved to be an essential step, complementing the hydrocyclone and sand filter for efficient removal. The results indicate that density and particle size directly influence process efficiency, with PVC being more easily removed in the initial stage, while PE and AC remained in the system for a longer period. The combination of materials provided better overall performance, highlighting the importance of a hybrid treatment that integrates different technologies to optimize microplastic removal.