Presença, identificação e caracterização de microplásticos em uma estação de tratamento de água de um município do norte do Paraná

Abstract

The large use of plastic materials and their importance in everyday life has become the focus of recent environmental concerns, mainly due to their improper disposal. Used on a large scale, plastic waste reaches aquatic ecosystems in abundance, where it undergoes degradation processes, generating a new class of emerging contaminants: microplastics (fragments smaller than 5mm in diameter). In recent years, several studies have reported the presence of these microplastics in aquatic ecosystems, raising questions and concerns regarding the impacts that this contaminant in drinking water can have on human health and ecosystems. This problem becomes a concern when microplastics are present in freshwater sources (surface and aquifers) in small concentrations. In this case, detection and removal becomes difficult, directly influencing the determination of the use of this water. The main objective of this study is to investigate the possible presence of microplastics in a Water Treatment Plant located in the North of the State of Paraná, being collected samples of raw water and after each stage of treatment of the WTP, as well as to evaluate the treatments used in relation to the presence of these contaminants. After collection with glass vials, the samples will undergo digestion of organic matter, separation by density and filtration, to be visually analyzed under a stereoscope, in order to identify the shape, size and quantity of microplastics. To analyze the morphology of the microplastics, the Scanning Electron Microscopy (SEM) technique will be used, which generates high-resolution images. The identification of the functional groups present in the structure of microplastics will be performed by Fourier Transform Infrared Spectrometry (FT-IR), using a spectrometer (NIR/MIR Frontier, PerkinElmer) in transmittance mode and X-ray diffraction (XRD). Morphological and color analysis revealed a predominance of microplastics classified as fibers, followed by fragments, with varied colors, where blue, transparent-white, and yellow were the most frequent. Regarding the sizes found, lengths smaller than 1 mm were more frequent, representing 52.73%. Microparticles from 1 mm to 3 mm represented 43.64%, with microparticles with lengths between 3 mm and 5 mm being less frequent (3.64%). Physicochemical analyses confirmed the presence of polymers in all treatment stages, such as polyester (PES) and cellophane. The results obtained reinforce the importance of adopting preventive measures and public policies focused on reducing microplastic pollution in treatment processes. This study contributes to the understanding of microplastics in supply systems, serving as a foundation for future research and actions aimed at preserving water resources.