Abstract：
Nowadays the proliferation of microplastics (MPs) in aquatic environments and impacts on the fate of organic contaminants (OCs) has drawn sustained worldwide attention. In this study, we investigated the effects of different types and aging degrees of MPs, specifically polystyrene (PSMPs), polyethylene terephthalate (PETMPs), and polylactic acid (PLAMPs), on the photo-transformation of LSTPs. Our results revealed that the facilitation of LSTP photoconversion by PSMPs exhibited a positive linear relationship with aging degree. On the other hand, the effects of PETMPs with different oxidation levels on LSTP photoconversion were weak, while the contribution of PLAMPs decreased as aging increased. Characterizations, quenching and probing experiments showed the aging mechanisms and the generation of reactive oxygen species (ROS) converged among various MPs. Specifically, theoretical calculations, TOC and GC-MS were conducted to verify that in the PLA0-mediated systems, it was the intermediates of PLA0 that prevailed in promoting the photoconversion of LSTP. The aged PLA own have a large propensity to consume ROS, which diminished their promotion of LSTP degradation. This differd from the reactions involving PSMPs and PETMPs, where the microplastic particles themselves were the main drivers of the photoconversion process rather than intermediates.
摘要：
如今，微塑料（MPs）在水生环境中的扩散以及对有机污染物（OCs）命运的影响已引起全世界的持续关注。在这项研究中,我们调查了不同类型和老化程度的影响，特别是聚苯乙烯(PSMP)，聚对苯二甲酸乙二醇酯(PETMPs),和聚乳酸（PLAMP），关于LSTP的照片转换。我们的结果表明，PSMPs对LSTP光转换的促进作用与老化程度呈正线性关系。另一方面,不同氧化水平的PETMPs对LSTP光转化的影响较弱,而PLAMP的贡献随着衰老的增加而减少。表征,淬火和探测实验表明，老化机制和活性氧（ROS）的产生在各种MPs之间趋同。具体来说,理论计算，进行TOC和GC-MS以验证在PLA0介导的系统中，PLA0的中间体在促进LSTP的光转化中占主导地位。老年人本身有很大的消费ROS的倾向，这减少了它们对LSTP降解的促进。这不同于涉及PSMPs和PETMPs的反应，其中微塑料颗粒本身是光转换过程的主要驱动因素，而不是中间体。
