Avaliação da presença de microplásticos em esgoto sanitário do município de Campo Mourão – PR

Abstract

Since its discovery, plastic is increasingly inserted in people's daily lives in different aspects, presenting different sizes and colors of the most diverse. Authors define that microplastics are particles smaller than 5 mm that are increasingly present in the environment and can be manufactured in micrometer sizes (primary microplastics) or, a macroplastic, which can suffer various weather or mechanical forces until fragmented and have small sizes (secondary microplastics). Primary microplastics are present in everyday cosmetics, such as soaps or toothpastes, so these microparticles are disposed of in domestic sewage arriving at Sewage Treatment Stations (ETEs). Microplastics present in synthetic fabrics (fibers), when undergoing the washing process, also end up being disposed of in the domestic sewage and reach the WWTP. Despite the treatment system, some particles are not retained during the process and are discarded with the final effluent to the receiving water body. Thus, the objective of the present study was to investigate the presence and what are the types of microplastics in sanitary sewage that reach the WWTP of Campo Mourão, Paraná. Forty liters of raw and treated domestic sewage were collected and filtered at the municipal WWTP. All material retained in the filtration was subjected to analysis and laboratory processes to determine the total waste mass, oxidize the organic matter, observe the density range of the particles and finally, visual analysis of the microplastics. As a result it was observed that the type of microplastic with the largest presence in the raw and treated sewage, are the synthetic fibers that make up the fabrics and are released by residential washes. It was also observed the presence of secondary microplastics classified as fragments, colored and colorless, in both raw and treated sewage. Thus, it is necessary to expand the studies on microplastics in relation to their emitting sources; what are the consequences for human organisms; what are the alternatives to decrease the generation of these particles; how the efficiency of WWTPs can be improved for better retention efficiency of microplastics; and study sewage sludge as a source of entry of microplastics in the terrestrial environment.