German Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz, Germany.
German Federal Highway Research Institute (BASt), Bruederstraße 53, 51427 Bergisch Gladbach, Germany.
Sci Total Environ. 2021 Jan 15;752:141939. doi: 10.1016/j.scitotenv.2020.141939. Epub 2020 Aug 24.
Tyre and road wear is one of the main emission sources of particulate plastics (microplastics). In this study, the emissions of tyre wear particles (TWP) which are annually generated on the German road network were calculated. Emissions are calculated by applying two different data sets of emission factors and the annual mileage for distinct vehicles and road types (urban roads, rural roads, highways). Environmental entry paths of tyre and road wear particles (TRWP) were considered including releases to ambient air, soils and surface waters. Road runoff treatment was taken into account differentiated into sewage systems in urban areas and at non-urban roads. This study identifies the soundest data available concerning emission factors, data on traffic and road systems as well as comprehensive information on road runoff treatment in Germany. Applying this data and assuming that 5% of the total emissions are 'fine' air-borne particles, the emissions of coarse 'non-airborne' particles are 75,200-98,400 t/a; . the transport to road banks and soils near roads is 57,300-65,400 t/a (66-76%) including runoff and drift; 8700-19,800 t/a (12-20%) are released to surface waters. Due to lack of data, degradation in soils and surface waters was not considered. Besides soils, urban wastewater treatment plants are expected to be an important sink of TRWP assuming that most of the particles are incorporated in the sewage sludge. Due to the application of sewage sludge as a fertilizer, 1400-2800 t/a TWP are currently deposited on agricultural areas. No reliable data was available to estimate the masses of TWP which are transported from freshwaters into the marine environment. Existing mitigation measures should be improved according to the principle of precaution by installation of road runoff treatment systems and retrofitting of existing plants regarding optimum fine particle retention.
轮胎和道路磨损是微粒塑料（微塑料）的主要排放源之一。本研究计算了德国道路网络上每年产生的轮胎磨损颗粒（TWP）的排放量。排放量是通过应用两种不同的排放因子数据集和不同车辆和道路类型（城市道路、农村道路、高速公路）的年行驶里程来计算的。考虑了轮胎和道路磨损颗粒（TRWP）的环境进入途径，包括释放到环境空气中、土壤中和地表水。考虑到城市地区和非城市道路的污水系统，对道路径流处理进行了区分。本研究确定了德国有关排放因子、交通和道路系统数据以及道路径流处理的最全面信息。应用这些数据并假设总排放量的 5%是“细”空气传播颗粒，则粗“非空气传播”颗粒的排放量为 75200-98400 吨/年；57300-65400 吨/年（66-76%）通过径流和漂移输送到道路堤岸和道路附近的土壤中；8700-19800 吨/年（12-20%）释放到地表水。由于缺乏数据，未考虑土壤和地表水的降解。除了土壤之外，城市废水处理厂预计将成为 TRWP 的一个重要汇，假设大部分颗粒都包含在污水污泥中。由于将污水污泥用作肥料，目前有 1400-2800 吨/年的 TWP 沉积在农业区。由于没有可靠的数据来估计从淡水进入海洋环境的 TWP 质量。应根据预防原则，通过安装道路径流处理系统和改进现有工厂以实现最佳细颗粒截留，来改进现有的缓解措施。
