Han Limei, Seiwert Bettina, Lichtenwald Emily, Weyrauch Steffen, Zahn Daniel, Reemtsma Thorsten
Department of Environmental Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
Department of Environmental Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany; Institute of Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany.
Water Res. 2025 Jul 15;286:124235. doi: 10.1016/j.watres.2025.124235.
Para-phenylenediamines (PPDs) are antioxidants added to tires to protect the rubber. They are released from tire and road wear particles (TRWP) but the extent of their aerobic microbial degradation and the transformation products (TPs) formed are not known. Therefore, aerobic microbial degradation of seven tire-related PPDs, parent compounds as well as known transformation products, was studied for up to 28 days. Half-lives ranged from 0.2 ± 0.1 days (N-(1,3-dimethylbutyl)-N'-phenyl-1,4-benzenediamine, 6-PPD) and 0.6 ± 0.1 days (N-isopropyl-N'-phenyl-1,4-phenylenediamine, IPPD) to 3 ± 0.1 days (N-(1,3-dimethylbutyl)-N'-phenyl-1,4-benzenediamine quinone, 6-PPDQ). A total number of 48 TPs was tentatively identified by liquid chromatography-high resolution-mass spectrometry for the seven study compounds. Of these TPs, only four did not decrease in concentration when the parent compounds were degraded completely. Biotransformation in aqueous solution forms several TPs not known for abiotic, photolytic or oxidative transformation. For the PPDs with aliphatic substituents (6-PPD, IPPD) hydrolysis to 4-HDPA was the major initial transformation. Formation of 6-PPDQ from 6-PPD was not detectable. For the fully aromatic DPPD aerobic microbial transformation, likely, proceeded via a quinone diimine intermediate, leading to products different to those of the aliphatic PPDs. From 6-PPDQ, 26 TPs were detected. A suspect screening for the TPs detected from the biodegradation experiments was performed in data of a soil degradation study over 23 months with TRWP and cryo-milled tire tread (CMTT) and in data from the influent and effluent of a municipal wastewater treatment plant during a rain event. In total, 10 TPs were found in those data with variable intensities, most of which originated from 6-PPDQ. While all seven test compounds were (primary) degraded under aerobic conditions, mineralization was not studied. A number of TPs remain as suspects to search for in the environment.
对苯二胺（PPDs）是添加到轮胎中以保护橡胶的抗氧化剂。它们会从轮胎和道路磨损颗粒（TRWP）中释放出来，但它们的需氧微生物降解程度以及形成的转化产物（TPs）尚不清楚。因此，研究了七种与轮胎相关的PPDs（母体化合物以及已知的转化产物）的需氧微生物降解情况，为期长达28天。半衰期范围从0.2±0.1天（N-（1,3-二甲基丁基）-N'-苯基-1,4-苯二胺，6-PPD）和0.6±0.1天（N-异丙基-N'-苯基-1,4-苯二胺，IPPD）到3±0.1天（N-（1,3-二甲基丁基）-N'-苯基-1,4-苯二胺醌，6-PPDQ）。通过液相色谱-高分辨率质谱法初步鉴定出七种研究化合物总共48种TPs。在这些TPs中，只有四种在母体化合物完全降解时浓度没有降低。水溶液中的生物转化形成了几种非生物、光解或氧化转化所未知的TPs。对于具有脂肪族取代基的PPDs（6-PPD、IPPD），水解为4-HDPA是主要的初始转化。未检测到由6-PPD形成6-PPDQ。对于完全芳香族的DPPD，需氧微生物转化可能通过醌二亚胺中间体进行，导致形成与脂肪族PPDs不同的产物。从6-PPDQ中检测到26种TPs。在一项为期23个月的土壤降解研究（使用TRWP和低温研磨轮胎胎面（CMTT））的数据以及降雨事件期间城市污水处理厂进水和出水的数据中，对生物降解实验中检测到的TPs进行了可疑物筛查。在这些数据中总共发现了10种强度各异的TPs，其中大部分源自6-PPDQ。虽然所有七种测试化合物在需氧条件下都（主要）被降解，但未研究矿化情况。仍有许多TPs作为可疑物有待在环境中寻找。
