Department of Civil and Environmental Engineering , University of California, Berkeley , Berkeley , California 94720 , United States.
Environmental Technologies Area , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.
Environ Sci Technol. 2018 Oct 16;52(20):11913-11921. doi: 10.1021/acs.est.8b02977. Epub 2018 Sep 25.
Diesel particle filters (DPFs) are standard equipment on heavy-duty diesel trucks with 2007 and newer engines in the U.S. This study evaluates the performance and durability of these filters. Black carbon (BC) emission rates from several thousand heavy-duty trucks were measured at the Port of Oakland and Caldecott Tunnel over multiple years as California regulations accelerated the adoption of DPFs. As DPF use increased, fleet-average BC emissions decreased, and emission factor distributions became more skewed. Relative to 2004-2006 engines without filters, DPFs reduced BC emission rates by 65-70% for 2007-2009 engines and by >90% for 2010+ engines. Average BC emission rates for 2007-2009 engines increased by 50-67% in 2015 relative to measurements made 1-2 years earlier. Some trucks in this cohort have become high-emitters, indicating that some DPFs are no longer working well. At the Port, where DPFs were universal in 2015, high-emitting 2007-2009 engines (defined here as emitting >1 g BC kg) comprised 7% of the fleet but were responsible for 65% of the total BC emitted. These observations raise concerns about DPF durability and the prospects for fully mitigating adverse effects of diesel particulate matter on human health and the environment.
在美国，2007 年及以后生产的重型柴油卡车都配备了柴油颗粒过滤器（DPF）。本研究评估了这些过滤器的性能和耐久性。在加利福尼亚州法规加速推广 DPF 的几年里，对奥克兰港和卡尔德科特隧道的数千辆重型卡车进行了黑碳（BC）排放率的测量。随着 DPF 的使用增加，车队平均 BC 排放量下降，排放因子分布变得更加偏态。与没有过滤器的 2004-2006 年发动机相比，2007-2009 年发动机的 DPF 将 BC 排放率降低了 65-70%，而 2010 年及以后的发动机则降低了>90%。与 1-2 年前的测量值相比，2007-2009 年发动机的平均 BC 排放率在 2015 年增加了 50-67%。该队列中的一些卡车已成为高排放者，表明一些 DPF 已不再正常工作。在 2015 年 DPF 已普及的港口，高排放的 2007-2009 年发动机（定义为排放>1 g BC kg）占车队的 7%，但却占总 BC 排放量的 65%。这些观察结果引起了人们对 DPF 耐久性以及全面减轻柴油颗粒物对人类健康和环境的不利影响的前景的担忧。
