Microplásticos: impacto ambiental de polímeros fotodegradados

Abstract

Plastics have been studied for their environmental impact, since when discarded in the environment they do not disappear. Over time they degrade and fragment into smaller pieces, reaching the microscale. When exposed to sunlight these materials can photodegrade, generating fragments that can be consumed by animals, either directly when confused with food or indirectly when they ingest contaminated food/animals. One way to verify and quantify the microplastics (MP) present in marine animals and invertebrate is through advanced oxidative processes (AOP). AOPs are mainly used in oxidation of persistent contaminants, but they have been used to separate organic matter and plastic fragments because of their oxidative power. In order to verify if the AOPs aggravate in some way the fragmentation of degraded polymer, it was proposed to analyze the interaction between AOPs, such as Fenton reaction and alkaline solution, and polymer samples with different photodegradation levels. Superficial changes were observed in some samples with advanced degradation levels, with higher carbonyl concentrations. Comparing the level of degradation, samples with higher carbonyl concentration showed variations post-tested, while samples without or withlow concentration of carbonyl showed no variations. With these results it was possible to confirm the interaction of some AOPs with photodegraded materials and, therefore, that this type of analysis can interfere with the amount of fragments obtained after chemical digestion of marine animals and/or invertebrate. This result helps to put into perspective the research done with invertebrates that had degraded polymers as part of their diet, since there may be an incorrect extrapolation in the amount of MP present in these animals.