Institute of Atmospheric Pollution Research, National Research Council of Italy, Area della Ricerca di Roma 1 - AdR RM1, Strada Provinciale 35d, 9, 00010, Montelibretti, (RM), Italy.
Environ Sci Pollut Res Int. 2023 Sep;30(45):100282-100300. doi: 10.1007/s11356-023-29229-7. Epub 2023 Aug 25.
Brake wear emission is a significant contributor to vehicle-related particulate matter, especially in areas with high traffic density and braking frequency. Only recently, non-exhaust emissions from car brake wear have been regulated under Euro 7 regulation, which introduces emission limits for both brake and tires. It also introduces a standard brake particle assessment procedure which includes sampling procedure and measurement techniques defined in the Global Technical Regulation on brakes from light-duty vehicles up to 3.5 t. Over the years, various experimental setups have been tried leading to non-comparable results. The brake wear particle emissions, expressed as emission factors, are mostly estimated as particle mass or particle number and described using different units (e.g., mg/stop brake, mg/km brake; particle number/cm) making the comparison between studies very difficult. The aim of the present literature review is to present the state-of-the-art of different experimental methods tuned for assessing brake wear emissions, including electric vehicles. The experiments are carried in close, semi-closed, and open systems, and depending on the experimental design, different sampling methods are applied to reduce particle transport loss and guarantee the efficiency of the particle sampling. Driving condition (e.g., speed and applied pressure), formulation of brake materials, and friction temperature have been found to strongly affect the emission characteristics of brake particles, and this needs to be considered when designing study procedures. The findings reported in this review can be beneficial to policy makers and researchers.
制动磨损排放是车辆相关颗粒物的主要来源，特别是在交通密度和制动频率较高的地区。直到最近，欧盟 7 号法规才开始规范汽车制动磨损产生的非尾气排放，该法规为制动和轮胎都设定了排放限值。它还引入了一个标准的制动颗粒评估程序，其中包括在全球轻型车辆至 3.5 吨以下的制动用全球技术法规中定义的采样程序和测量技术。多年来，已经尝试了各种实验装置，导致结果无法进行比较。制动磨损颗粒排放（以排放因子表示）大多以颗粒质量或颗粒数量来估算，并使用不同的单位来描述（例如，每刹车停止毫克，每刹车公里毫克；颗粒数量/立方厘米），这使得研究之间的比较非常困难。本文献综述的目的是介绍针对制动磨损排放评估的不同实验方法的最新技术，包括电动汽车。实验在封闭、半封闭和开放系统中进行，根据实验设计，应用不同的采样方法来减少颗粒传输损失并保证颗粒采样的效率。已经发现行驶条件（例如速度和施加的压力）、制动材料配方和摩擦温度强烈影响制动颗粒的排放特性，在设计研究程序时需要考虑这些因素。本综述中报告的发现可以为政策制定者和研究人员提供有益的信息。
