Speciated PM Composition and Gas and Particle Emission Factors for Diesel Construction Machinery in China

On-board emission measurements were performed on nine diesel construction machines operated under real-world conditions in China. The emission factors (EFs) for NOx, CO, the total hydrocarbons, PM, and the particle number concentration were determined under actual operating conditions, i.e., during idling, moving, and working. To investigate the chemical composition of PM from diesel machinery, organic carbon (OC), containing particulate organic matter (POM); elemental carbon (EC); water-soluble ions (WSIs); and elements were also analyzed herein. OC was the most abundant component (contributing 39.3 ± 11% of the mass), followed by EC (37.7 ± 13%). POM species, including n-alkanes, hopanes, polycyclic aromatic hydrocarbons (PAHs), and n-fatty acids, contributed approximately 2.4–6.4% of the total PM mass. Compounds with 3 or 4 aromatic rings, including pyrene, phenanthrene, and fluoranthene, dominated the particulate PAHs, accounting for 62% of the total mass. These results are consistent with those of previous studies and can help to minimize uncertainties in emission inventories and source apportionment for non-road machinery.