Contribution of Aftertreatment Technologies to Alleviating SOA and Toxicity Generation from Typical Diesel Engine-Emitted I/SVOCs
Yaoqiang Huo, Jianguo Liu, Di Wu, Yuankai Shao, Xiwen Song, Zihua Guo, Anlin Liu, Qing Li, Jianmin Chen
Abstract
The removal capacity of aftertreatment technologies equipped on diesel exhaust in intermediate and semivolatile organic compounds (I/SVOCs) remains unclear. This study quantified the effect of typical aftertreatment technologies (China VI) on diesel engine-emitted I/SVOCs, related secondary organic aerosol (SOA), and toxic effects. The equipped aftertreatment devices could mitigate the emission factors (EFs) by 70.8 ± 3.4 to 82.5 ± 20.9% for I/SVOCs, 72.7 ± 18.6 to 77.5 ± 4.2% for SOA production, and 75.7 ± 9.3 to 82.4 ± 9.2% for toxic equivalent quantity (TEQ). Aftertreatment units are better for removing alkanes, benzenes, and ketones. The TEQ from the cold-start cycle is 1.3- to 5.7-fold higher than that from the hot-start cycle. In contrast, the EFs of ship-emitted I/SVOCs are 3.7- to 5.3-fold higher than those of diesel vehicles equipped with an aftertreatment system when burning the same fuel, leading to 2.1- to 3.0-fold higher SOA production and 3.1- to 6.7-fold TEQ. Implementation of control devices on marine diesel engines could reduce I/SVOC EFs, SOA production, and eye irritation TEQ of ships by 76.7 ± 12.2, 75.1 ± 12.2, and 79.1 ± 9.6%, respectively. These results indicate that it is vital to equip marine engines with aftertreatment technologies to improve air quality and protect human health.