Pellets plásticos em praias arenosas em duas áreas portuárias do Estado do Ceará

Abstract

Plastics are synthetic or natural organic polymers, whose world production has increased since the mid-twentieth century. While they are beneficial to society, plastics generate waste, which is divided from mega to nanoplastics. In the category of microplastics, there are plastic pellets. Pellets (thermoplastic resins) are plastic granules that serve as raw material for the industry. Since the beginning of the 20th century, concern about these wastes has increased due to the marine threat they pose. Due to the importance of the marine environment, the objective of this study was to detect the presence, to characterize them and to determine the degree of pollution of a beach according to the index of pollution by pellets (IPP), as well as to determine the polymer composition of the pellets. Two port areas of the state of Ceará were chosen: Port of Fortaleza and Port of Pecém. There were four collections (May to June / 17). The areas adjacent to the port of Fortaleza de FA and FP and the Pecém de PA and PP were determined and sediments were collected in 10 points of each area, in the most recent high tide line. The pellets were separated, quantified and characterized (size, shape, transparency and color). The PPI was calculated from a standard equation and the statistical analysis was similarity. To identify the types of polymers, a spectrophotometer and a spectral library with common reference spectra were used through the algorithm program. 1,411 pellets were collected during the research. Two pellets were identified in FA, in the first collection and none in FP, whereas in PA and PP resins were identified. In June more pellets (38.6 pellets / m²) were found. The morphology most found in PA was cylindrical and in PP the spherical flattened (exception of July). The most frequent colors were white, yellow and amber, in all months. 170 classes were identified from the characterization, as well as pellets of 6 and 8 mm. By spectroscopy, 73.75% were PE, 24.28% PP and 0.07% PA and by density 71.56% were PE and 28.44% PP. The percentage error between the two methods ranged from 13.33% to 23.75% for PP and 0.29 to 5.64% for PE. There was no significant difference between the methods. It was concluded that only 8.58% of the studied Pecém beach strips are polluted at a high or very high level, while 92% is considered as having a moderate, low or very low level of pollution. Therefore, the calculation of the IPP was efficient to determine the degree of pollution of the beaches studied here. The most common types of polymers were PE and PP and both methods can be used to identify them.