Programa de Pós-Graduação Em Oceanologia, Instituto de Oceanografia, Universidade Federal Do Rio Grande (FURG), Av. Itália Km 8, Rio Grande, RS, 96203-900, Brazil.
Escola de Química E Alimentos, Universidade Federal Do Rio Grande (FURG), Av. Itália Km 8, Rio Grande, RS, 96203-900, Brazil.
Environ Sci Pollut Res Int. 2023 Dec;30(58):121450-121464. doi: 10.1007/s11356-023-30925-7. Epub 2023 Nov 11.
This study investigated the influence of environmental factors (UV radiation and salinity) in the degradative process of microplastics (MPs). MPs derived from polypropylene (PP), polystyrene (PS), and ethylene-vinyl acetate (EVA) were subjected to accelerated photodegradation while being submerged in distilled water or artificial seawater. Depending on the polymer, changes in surface properties, new functional chemical group formation and oxidative index, and thermal characteristics of samples were observed. After photodegradation experiments, EVA-MPs samples showed an increase in their thermal resistance, besides the changes in their surface. PP-MPs crystallinity index increased upon exposure to UV radiation. PS samples showed a higher carbonyl and hydroxyl index after 30 h of UV exposure. The methodology exploited applies to any location in the world and can be comparable once considering the total ultraviolet index (UVI). The saline medium increases the crystallinity index of PP and EVA-MPs samples and intensifies the formation of new carbonyl and hydroxyl bonds in EVA-MPs samples. The results showed that several environmental factors should be considered in interpreting MPs photodegradation.
本研究调查了环境因素（紫外线辐射和盐度）对微塑料（MPs）降解过程的影响。源自聚丙烯（PP）、聚苯乙烯（PS）和乙烯-醋酸乙烯酯（EVA）的 MPs 在蒸馏水中或人工海水中进行加速光降解。根据聚合物的不同，观察到样品表面性质的变化、新官能团的形成和氧化指数以及热特性。光降解实验后，EVA-MPs 样品表现出热稳定性增加，而表面发生了变化。PP-MPs 的结晶度指数在暴露于紫外线辐射后增加。PS 样品在暴露于紫外线 30 小时后显示出更高的羰基和羟基指数。所采用的方法适用于世界上任何地方，并且可以在考虑总紫外线指数 (UVI) 的情况下进行比较。盐度介质增加了 PP 和 EVA-MPs 样品的结晶度指数，并加剧了 EVA-MPs 样品中新的羰基和羟基键的形成。结果表明，在解释 MPs 光降解时应考虑多种环境因素。
