School of Environmental Studies, China University of Geosciences, Wuhan, Hubei 430074, China.
Department of environmental engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China.
Water Res. 2024 Jun 15;257:121669. doi: 10.1016/j.watres.2024.121669. Epub 2024 Apr 23.
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.
轮胎磨损颗粒（Tire wear particles，TWPs）被认为是暴雨事件中污泥中微塑料（Microplastics，MPs）的重要来源。大量研究表明，污泥的热液处理（Hydrothermal treatment，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，TWPs 在污泥 HT 中的浸出行为仍未得到充分探索。本研究使用液相色谱-串联质谱（LC-MS/MS）结合质量差分析，研究了不同热液温度下轮胎相关添加剂的代表性轮胎磨损颗粒衍生化合物的分子组成和转化途径。利用青海弧菌 Q67 和水稻水培实验评估了 TWP 浸出物的急性毒性和植物毒性。结果表明，提高热液温度不仅放大了 TWPs 的浸出行为，还增强了 TWP 浸出物的化学复杂性。利用可疑和非靶向筛选，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-p-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，如不饱和、乙酰化和其他反应，导致形成不同的转化产物（TPs）。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，有可能与氨基酸或美拉德产物形成共轭产物。同时，TWP 衍生化合物表现出显著的急性毒性和对植物生长的不利影响。本研究系统地研究了 TWPs 及其衍生化合物在污泥 HT 过程中的环境归宿，为深入了解微污染物与污泥中溶解有机物（DOM）之间的复杂相互作用提供了新的见解。
