Influence of microplastic decomposition conditions on the emission of substances harmful to the environment

Abstract

The work described the research on the possibility of the emission of plastic components under various environmental conditions. The research carried out aimed to estimate the amount of plasticizer emission from microplastics in the example of a used tire during its decomposition in an aqueous medium. The tests conducted confirmed that, depending on environmental conditions, tire particles are washed out, among others, of phthalic acid esters, benzenediamine, phenol, benzothiazole, and benzene. The analyzes conducted show that the pH value, temperature of the reaction medium, and incubation time have a significant influence on the elution mechanisms of the plasticizers from the polymer matrix. Sufficiently high temperatures can be a factor that causes partial decomposition of plasticizers. However, under natural conditions, the temperature in the aquatic ecosystem is too low to initiate the degradation process and, at the same time, sufficient to release the auxiliary components contained in the tires. An additional negative aspect of the distribution of tire particles in the aquatic environment is the emission of carbon dioxide and methane, which are greenhouse gases. There was also a significant increase in total organic carbon and fluctuations in pH values. The study also estimated the ecotoxicological risk of the plasticizers analyzed.