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Contamination by microplastics (MPs) has been recorded in various environments and organisms around the world. The objective of this study was to investigate the occurrence of MPs in two species of Siluriformes fishes Pterygoplichthys pardalis and Hoplosternum littorale considering the sex and different body parts of fish captured in Amazon floodplain areas, which are marketed and consumed in the Municipality of Itacoatiara, Amazonas, Brazil. One hundred and fifty individuals of each fish species were analyzed for microplastics. Of these, 252 individuals were found to contain MPs: 127 (85%) P. pardalis and 125 (83%) H. littorale. The fish were contaminated with 683 MP particles, ranging from 1 to 43 MP particles/individual, with an average of 2.71 ± 3.2 MP particles/individual P. pardalis and H. littorale. Comparison of MP occurrence and particle size between species, sex, and body part found no significant difference. Fiber-shaped and blue-colored MPs were the most abundant in both P. pardalis (80% and 85.5%, respectively) and H. littorale (92% and 85%, respectively). The particles were identified as polyethylene terephthalate and polystyrene. The results indicate MP contamination in P. pardalis and H. littorale catfish, which are widely consumed by Amazonian riverside communities. These species are often cooked whole (including the viscera) becoming a direct route of microplastic contamination to humans. [ABSTRACT FROM AUTHOR]

In the present work, mesoporous ZSM-5 zeolite structures were developed by means of post-synthesis modification and direct synthesis and the materials were applied as pyrolysis catalysts of different sources of plastic waste. The plastic wastes were purchased from a cooperative of selective collection, classified as polyethylene, polypropylene and polystyrene, which were used in plastic mixtures with quantities consistent with the Brazilian Association of the Plastic Industry (ABIPLAST) in order to simulate urban plastic waste in Brazil. Previously, these plastic waste mixtures were extruded with 10% m/m of catalyst and thermogravimetric analysis was performed. It was possible to observe the decrease in degradation temperatures, as well as additional degradation steps in catalytic pyrolysis compared to thermal pyrolysis. The synthesized mesoporous ZSM-5 zeolite was the catalyst with higher performance in the pyrolysis of plastic waste mixtures due to the higher proportion of strong to weak acid sites. [ABSTRACT FROM AUTHOR]

The annual production of plastics has doubled over the past 15 years and, consequently, a large amount of plastic has accumulated in the environment generating ecological problems. In this study, a Paenibacillus sp. isolate was obtained from a landfill from Brazil and it presented the alkane hydroxylase gene (alkB). Weight loss of low-density polyethylene (LDPE) was measured and a significant difference in final weight compared to initial weight was assessed. Some chemical characteristics, such as bond scissions and formation of new functional groups [carboxylic acids (3300–2500 cm−1), esters (1210–1163 cm−1), and ethers (1075–1020 cm−1)], were detected by Fourier-transform infrared spectroscopy. Bacterial colonization on the plastic surface and physical changes, as formation of cracks and pits, was visualized by scanning electron microscopy. This isolate was susceptible to all the antimicrobials tested. Therefore, this isolate possesses great potential to degrade polyethylene and become an option for LDPE bioremediation. [ABSTRACT FROM AUTHOR]