Polyethylene terephthalate (PET) microplastics constitute a significant portion of plastic pollution in the environment and pose substantial environmental challenges. In this study, the effectiveness of the Fenton process and post-oxidation coagulation for the removal of non-weathered and UV-weathered PET microplastics (PET MPs) were investigated. A response surface methodology was used to investigate the interplay between PET concentration and ferrous ion (Fe2+) concentration. The models revealed an intricate interplay between these variables, highlighting the need for a balanced system for optimal PET MP removal. For non-weathered PET, the simultaneous increase in the concentrations of both PET microplastics and Fe2+ was found to enhance the removal efficiency. However, this synergistic effect was not observed in UV-weathered PET, which also demonstrated a more pronounced effect from the Fe2+ concentration. The statistical analysis provided a strong basis for the validity of the models. X-ray photoemission spectroscopy (XPS) further elucidated the mechanisms behind these findings, revealing that UV weathering results in surface changes, which facilitate hydroxyl radical oxidation. These findings underline the complexity of the Fenton process in PET microplastic removal and the different behavior of non-weathered and UV-weathered microplastics. This has significant implications for tailoring remediation strategies and underscores the importance of considering environmental weathering in these strategies.

中文翻译：

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原始和紫外线风化 PET 微塑料作为水污染物：评估芬顿工艺有效修复的潜力

聚对苯二甲酸乙二醇酯（PET）微塑料构成了环境中塑料污染的重要组成部分，并带来了巨大的环境挑战。在本研究中，研究了芬顿工艺和氧化后混凝去除未风化和紫外线风化 PET 微塑料 (PET MP) 的有效性。使用响应面方法研究 PET 浓度和亚铁离子 (Fe2+) 浓度之间的相互作用。这些模型揭示了这些变量之间复杂的相互作用，强调需要一个平衡系统来实现最佳 PET MP 去除。对于非风化 PET，同时增加 PET 微塑料和 Fe2+ 的浓度可以提高去除效率。然而，在紫外风化 PET 中并未观察到这种协同效应，这也表明 Fe2+ 浓度的效应更为明显。统计分析为模型的有效性提供了坚实的基础。 X射线光电子能谱（XPS）进一步阐明了这些发现背后的机制，揭示了紫外线风化会导致表面变化，从而促进羟基自由基氧化。这些发现强调了芬顿工艺去除 PET 微塑料的复杂性以及非风化和紫外线风化微塑料的不同行为。这对于制定修复策略具有重要意义，并强调了在这些策略中考虑环境风化的重要性。