Real-world emission for in-use non-road construction machinery in Wuhan, China.

Non-road construction machinery (NRCM) emissions pollutants significantly impact air quality. Six typical NRCM (2 excavators, 3 loaders, and 1 forklift) are analyzed based on a portable emission measurement system (PEMS) in Wuhan to estimate the real-world emission characteristics and chemical composition of PM of NRCM. The results show that the fuel-based average emission factors (EFs) of carbon monoxide (CO), hydrocarbon (HC), nitrogen oxides (NO), and particulate matter (PM) are 19.4 ~ 35.7 g kg fuel, 2.9 ~ 7.9 g kg fuel, 57.5 ~ 95.3 g kg fuel, and 1.8 ~ 2.6 g kg fuel for the tested NRCM. The high NO EF implies that the regulation of NO emission in Wuhan should be strengthened. In addition, the PM chemical composition profiles for NRCM show that the PM emitted from NRCM is dominated by organic carbon and elemental carbon (56.11 ~ 73.85%), followed by water-soluble ions (WSIs, 1.47 ~ 3.46%), and elements (0.16 ~ 0.41%). The major WSIs species are Cl, Na and NO, and the major elements are Ca, Na, and K, which are important markers for PM source analysis. The results of EFs and chemical composition emission characteristics of NRCM tailpipe pollutants obtained in the real-world can provide essential data support for accurately establish of emission inventory of non-road mobile sources in Wuhan.