He Shuiyuan, Sun Siyang, Xue Honghai, Kang Chunli, Yu Shuyi
Key Laboratory of Groundwater Resources and Environment, Jilin University, Ministry of Education, Changchun, 130021, China.
Key Laboratory of Groundwater Resources and Environment, Jilin University, Ministry of Education, Changchun, 130021, China; Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun, 130021, China.
Environ Res. 2023 May 15;225:115615. doi: 10.1016/j.envres.2023.115615. Epub 2023 Mar 5.
Plastics in the environment undergo various aging effects. Due to the changes in physical and chemical properties, the sorption behavior of aged microplastics (MPs) for pollutants differs from that of pristine MPs. In this paper, the most common disposable polypropylene (PP) rice box was used as the source of MPs to study the sorption and desorption behavior of nonylphenol (NP) on pristine and naturally aged PPs in summer and winter. The results show that summer-aged PP has more obvious property changes than winter-aged PP. The equilibrium sorption amount of NP on PP is summer-aged PP (477.08 μg/g) > winter-aged PP (407.14 μg/g) > pristine PP (389.29 μg/g). The sorption mechanism includes the partition effect, van der Waals forces, hydrogen bonds and hydrophobic interaction, among which chemical sorption (hydrogen bonding) dominates the sorption; moreover, partition also plays an important role in this process. Aged MPs' more robust sorption capacity is attributed to the larger specific surface area, stronger polarity and more oxygen-containing functional groups on the surface that are conducive to forming hydrogen bonds with NP. Desorption of NP in the simulated intestinal fluid is significant owning to intestinal micelles' presence: summer-aged PP (300.52 μg/g) > winter-aged PP (291.08 μg/g) > pristine PP (287.12 μg/g). Hence, aged PP presents a more vital ecological risk.
环境中的塑料会经历各种老化效应。由于物理和化学性质的变化，老化微塑料（MPs）对污染物的吸附行为与原始 MPs 不同。本文以最常见的一次性聚丙烯（PP）饭盒作为 MPs 的来源，研究了壬基酚（NP）在夏季和冬季原始及自然老化 PP 上的吸附和解吸行为。结果表明，夏季老化的 PP 比冬季老化的 PP 具有更明显的性质变化。NP 在 PP 上的平衡吸附量为夏季老化 PP（477.08 μg/g）＞冬季老化 PP（407.14 μg/g）＞原始 PP（389.29 μg/g）。吸附机制包括分配效应、范德华力、氢键和疏水相互作用，其中化学吸附（氢键）主导吸附过程；此外，分配在这一过程中也起着重要作用。老化 MPs 更强的吸附能力归因于其更大的比表面积、更强的极性以及表面更多有利于与 NP 形成氢键的含氧官能团。由于肠道微胶粒的存在，NP 在模拟肠液中的解吸显著：夏季老化 PP（300.52 μg/g）＞冬季老化 PP（291.08 μg/g）＞原始 PP（287.12 μg/g）。因此，老化的 PP 呈现出更大的生态风险。
