Tire wear particles (TWPs) are considered a significant contributor of microplastics (MPs) in the sludge during heavy rainfall events. Numerous studies have shown that hydrothermal treatment (HT) of sludge can accelerate the leaching of MP-derived compound into hydrothermal liquid, thus impairing the performance of subsequent anaerobic digestion and the quality of the hydrothermal liquid fertilizer. However, the leaching behavior of TWPs in the HT of sludge remains inadequately explored. This study examined the molecular composition of TWP-derived compounds and transformation pathways of representative tire-related additives under different hydrothermal temperatures using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with mass difference analysis. The acute toxicity and phytotoxicity of TWP leachates were assessed using Vibrio qinghaiensis Q67 and rice hydroponics experiments. The results indicated that elevating the hydrothermal temperature not only amplified the leaching behavior of TWPs but also enhanced the chemical complexity of the TWP leachate. Utilizing both suspect and non-target screenings, a total of 144 compounds were identified as additives, including N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6-PDD), hexa(methoxymethyl)melamine (HMMM), dibutyl phthalate (DBP). These additives underwent various reactions, such as desaturation, acetylation, and other reactions, leading to the formation of different transformation products (TPs). Moreover, certain additives, including caprolactam and 2,2,6,6-tetramethyl-4-piperidinol, demonstrated the potential to form conjugate products with amino acids or Maillard products. Meanwhile, TWP-derived compounds showed significant acute toxicity and detrimental effects on plant growth. This study systematically investigated the environmental fate of TWPs and their derived compounds during the HT of sludge, offering novel insights into the intricate interactions between the micropollutants and dissolved organic matter (DOM) in sludge.

中文翻译：

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污泥水热处理中轮胎磨损颗粒的浸出危害：探索轮胎磨损颗粒衍生化合物的分子组成、转化机制和生态效应


轮胎磨损颗粒（TWP）被认为是强降雨期间污泥中微塑料（MP）的重要贡献者。大量研究表明，污泥的水热处理（HT）会加速MP衍生化合物浸出到热液中，从而损害后续厌氧消化的性能和热液液体肥料的质量。然而，TWP 在污泥高温处理中的浸出行为仍未得到充分研究。本研究利用液相色谱-串联质谱（LC-MS/MS）结合质量差分析，研究了不同水热温度下TWP衍生化合物的分子组成和代表性轮胎相关添加剂的转化途径。利用青海弧菌Q67和水稻水培实验评估了TWP渗滤液的急性毒性和植物毒性。结果表明，提高水热温度不仅增强了TWP的浸出行为，而且提高了TWP浸出液的化学复杂性。通过可疑和非目标筛选，总共鉴定出 144 种化合物为添加剂，包括 N-(1,3-二甲基丁基)-N'-苯基-对苯二胺 (6-PDD)、六(甲氧基甲基)三聚氰胺 ( HMMM)、邻苯二甲酸二丁酯(DBP)。这些添加剂经历了各种反应，如去饱和、乙酰化等反应，导致形成不同的转化产物（TP）。此外，某些添加剂，包括己内酰胺和2,2,6,6-四甲基-4-哌啶醇，显示出与氨基酸或美拉德产物形成共轭产物的潜力。同时，TWP 衍生化合物表现出显着的急性毒性并对植物生长产生有害影响。 这项研究系统地研究了污泥高温处理过程中 TWP 及其衍生化合物的环境归趋，为污泥中微污染物与溶解有机物 (DOM) 之间复杂的相互作用提供了新的见解。