Relevância das partículas de pneu no total de microplásticos transportados pelo escoamento superficial em uma área urbana com elevada impermeabilização
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Data
2022-11-11
Autores
Goehler, Luiza Ostini
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Universidade Estadual Paulista (Unesp)
Resumo
Microplásticos (MPs) são considerados um poluente emergente e uma preocupação global. Atualmente adota-se uma definição abrangente de MPs, que inclui todos os materiais macromoleculares produzidos pelo homem, incluindo a borracha, portanto, as Partículas de Desgaste de Pneu (TWPs) são classificadas também como MPs. Dentre os diversos tipos de MPs, as TWPs apresentam elevada concentração em áreas urbanas e são transportadas principalmente pelo escoamento superficial, acumulando-se em corpos hídricos e reservatórios. O aumento das superfícies impermeáveis, associado à urbanização, e o elevado número de veículos pode acarretar uma maior quantidade de partículas em grandes metrópoles, como São Paulo. Nesse trabalho foram coletadas amostras do Reservatório de Detenção de Águas Pluviais (SDR) na Bacia Hidrográfica do Rio Aricanduva, São Paulo, para caracterização de MPs e TWPs. Para a separação dos MPs foi utilizado processo de separação por densidade e filtração em membranas de nitrato de celulose (poros de 0.45 µm). Os MPs foram contabilizados e caracterizados visualmente com utilização de microscópio stereo com câmera integrada. A área de contribuição possui cerca de 36 km², sendo 73% superfícies impermeáveis, e 640 km de arruamento. As TWPs foram o principal MP identificado (53%), seguido de fragmentos (30 %), fibras (9%), filmes (4%) e pellets (4%). O tamanho predominante foi de 0,1 mm a 0,5 mm, e nessa faixa as TWPs representaram 57% do total de MPs. Normalizando os dados, são obtidos índices de 2.160 unidades/kg.km² de área impermeável e 87,8 unidades/kg.km de arruamento. Esse tipo de dado nunca foi apresentado em estudos anteriores, e pode auxiliar no entendimento do comportamento desse poluente em áreas urbanas. Considerando o tráfego na área de contribuição, as emissões de TWPs calculadas variam de 43,3 a 205,5 kg/dia e o fluxo anual calculado foi de 7,8∙1011 unidades/km².ano para MPs e 4,1∙1011 unidades/km².ano para TWPs, demonstrando a predominância desse poluente. Sugere-se que estudos futuros apresentem também os índces de MPs e TWPs por área impermeável e comprimento de arruamento, visto que esses fatores, associados com o tráfego, são importantes para a mensuração de TWPs em áreas urbanas.
Microplastics (MPs) are considered an emerging pollutant and a global issue. Currently is adopted a general definition of MPs, which includes all man-made macromolecular materials, including rubber, therefore, Tire Wear Particles (TWPs) are also classified as MPs. Among the various types of MPs, TWP are highly concentrated in urban areas and are mainly transported by surface runoff, accumulating in water bodies and reservoirs. The increase in impervious surfaces, with urbanization, and the high number of vehicles can lead to a greater number of particles in large cities, such as São Paulo. In this work, samples were collected from the Stormwater Detention Reservoir (SDR) in the Aricanduva River Basin, São Paulo, for the characterization of MPs and TWPs. For the separation of the MPs, was used a process of separation by density and filtration in cellulose nitrate membranes (pores of 0.45 µm). The MPs were counted and visually characterized using a stereo microscope with an integrated camera. The contribution area has about 36 km², 73% are impermeable surfaces, and 640 km of roads.TWPs were the main MP identified (53%), followed by fragments (30%), fibers (9%), films (4%) and pellets (4%). The predominant size was from 0.1 mm to 0.5 mm, and in this range TWPs represented 57% of the total MPs. Normalizing the results, loads of 2,160 units/kg.km² of impermeable area and 87.8 units/kg.km of street surface are obtained. This type of data was not presented in previous studies and can help assess the behavior of this pollutant in urban areas. Considering the traffic in the contribution area, the calculated TWP emissions range from 43.3 to 205.5 kg/day and the calculated annual flow was 7.8∙1011 units/km².year for MPs and 4.1∙1011 units/km².year for TWPs, demonstrating the predominance of this pollutant. It is suggested that future studies also present the loads of MPs and TWPs by impermeable area and street length, since these factors, associated with traffic, are important for the contribution of TWPs in urban areas around the world.
Microplastics (MPs) are considered an emerging pollutant and a global issue. Currently is adopted a general definition of MPs, which includes all man-made macromolecular materials, including rubber, therefore, Tire Wear Particles (TWPs) are also classified as MPs. Among the various types of MPs, TWP are highly concentrated in urban areas and are mainly transported by surface runoff, accumulating in water bodies and reservoirs. The increase in impervious surfaces, with urbanization, and the high number of vehicles can lead to a greater number of particles in large cities, such as São Paulo. In this work, samples were collected from the Stormwater Detention Reservoir (SDR) in the Aricanduva River Basin, São Paulo, for the characterization of MPs and TWPs. For the separation of the MPs, was used a process of separation by density and filtration in cellulose nitrate membranes (pores of 0.45 µm). The MPs were counted and visually characterized using a stereo microscope with an integrated camera. The contribution area has about 36 km², 73% are impermeable surfaces, and 640 km of roads.TWPs were the main MP identified (53%), followed by fragments (30%), fibers (9%), films (4%) and pellets (4%). The predominant size was from 0.1 mm to 0.5 mm, and in this range TWPs represented 57% of the total MPs. Normalizing the results, loads of 2,160 units/kg.km² of impermeable area and 87.8 units/kg.km of street surface are obtained. This type of data was not presented in previous studies and can help assess the behavior of this pollutant in urban areas. Considering the traffic in the contribution area, the calculated TWP emissions range from 43.3 to 205.5 kg/day and the calculated annual flow was 7.8∙1011 units/km².year for MPs and 4.1∙1011 units/km².year for TWPs, demonstrating the predominance of this pollutant. It is suggested that future studies also present the loads of MPs and TWPs by impermeable area and street length, since these factors, associated with traffic, are important for the contribution of TWPs in urban areas around the world.
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Engenharia ambiental, Urbanização, Pneus, Impermeabilização, Plasticos, Microplastics, Tyre wear particles, Urbanization, Imperviousness, Street length