Weyrauch Steffen, Seiwert Bettina, Voll Milena, Wagner Stephan, Reemtsma Thorsten
Helmholtz-Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany.
Helmholtz-Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany; University of Leipzig, Institute of Analytical Chemistry, Linnéstrasse 3, 04103, Leipzig, Germany.
Sci Total Environ. 2023 Dec 15;904:166679. doi: 10.1016/j.scitotenv.2023.166679. Epub 2023 Sep 4.
Tire and road wear particles (TRWP) are generated in large quantity by automobile traffic on roads but their way of degradation in the environment is largely unclear. Laboratory experiments were performed on the effect of elevated temperature (simulating 2-3 years), sunlight exposure (simulating 0.5 years) and mechanical stress on the physical properties and chemical composition of TRWP and of cryo-milled tire tread (CMTT). No significant effects were observed of the applied mechanical stress on mean properties of pristine particles. After sunlight exposure up to 40 % in mass were lost from the TRWP, likely due to the loss of mineral incrustations from their surface. The chemical composition of TRWP and CMTT was characterized by determining 27 compounds, antioxidants (phenylene diamines), vulcanization agents (benzothiazoles and guanidines) and their transformation products (TPs). Extractables of TRWP (580-850 μg/g) were dominated by TPs, namely benzothiazolesulfonic acid (BTSA). CMTT showed much higher amounts of extractables (4600 μg/g) which were dominated by parent chemicals such as N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (6-PPD), diphenylguanidine (DPG) and mercaptobenzothiazole (MBT). Sunlight exposure affected the amount of extractables more strongly than elevated temperature, for TRWP (-45 % vs -20 %) and CMTT (-80 % vs -25 %) and provoked a clear shift from parent compounds to their TPs. After sunlight exposure extractables of TRWP were dominated by BTSA and DPG. Sunlight exposure drastically reduced the 6-PPD amount extracted from both, TRWP and CMTT (-93 %, -98 %), while its quinone (6-PPDQ) increased by around 1 % of the 6-PPD decrease, only. For many TPs, concentration in leachates were higher than in extracts, indicating ongoing transformation of their parent compounds during leaching. These results highlight that abiotic aging of TRWP leads to strong changes in their chemical composition which affect their particle properties and are of relevance for the environmental exposure to tire-related chemicals.
轮胎和道路磨损颗粒（TRWP）由道路上的汽车交通大量产生，但其在环境中的降解方式很大程度上尚不清楚。针对高温（模拟2 - 3年）、阳光照射（模拟0.5年）和机械应力对TRWP以及低温研磨轮胎胎面（CMTT）的物理性质和化学成分的影响进行了实验室实验。未观察到施加的机械应力对原始颗粒的平均性质有显著影响。在阳光照射后，TRWP质量损失高达40%，这可能是由于其表面矿物结壳的损失。通过测定27种化合物、抗氧化剂（苯二胺）、硫化剂（苯并噻唑和胍）及其转化产物（TPs）对TRWP和CMTT的化学成分进行了表征。TRWP的可提取物（580 - 850μg/g）以TPs为主，即苯并噻唑磺酸（BTSA）。CMTT显示出更高的可提取物含量（4600μg/g），其主要成分为母体化学物质，如N -（1,3 - 二甲基丁基）- N'-苯基 - 1,4 - 苯二胺（6 - PPD）、二苯基胍（DPG）和巯基苯并噻唑（MBT）。阳光照射对可提取物含量的影响比对TRWP（-45%对-20%）和CMTT（-80%对-25%）的高温影响更强，并导致从母体化合物到其TPs的明显转变。阳光照射后，TRWP的可提取物以BTSA和DPG为主。阳光照射极大地降低了从TRWP和CMTT中提取的6 - PPD含量（-93%，-98%），而其醌（6 - PPDQ）仅增加了6 - PPD减少量的约1%。对于许多TPs，渗滤液中的浓度高于提取物中的浓度，表明其母体化合物在浸出过程中持续转化。这些结果突出表明，TRWP的非生物老化导致其化学成分发生强烈变化，这会影响其颗粒性质，并且与环境中与轮胎相关化学品的暴露有关。
