Emission of particulate and gaseous pollutants from stationary diesel engine exhaust and examining their fate in the atmosphere through cause effect assessment

Abstract

Because of increased electric power demand and to meet the requirement during power-cut periods, use of non-road stationary diesel engines or diesel power generator engines is rising in all set-ups of urban establishments in both developed and developing nations across the globe. To develop the relationship between source of emission and ambient air quality with insights into development of emission factors and associated human health impact assessment, this study aimed to establish linkage between source, ambient air, and effects. Particulate matter and its inbuilt chemical constituents (elements, carbons, and inorganic ions) and gaseous pollutants were examined in this study. Elemental analysis suggested that the percentage of abundance of Ca, Mg and Si increased with engine-operating loads, and the values for Mn, Cd and Pb decreased with engine-operating loads. The results of the health impact assessment model revealed that implications due to deposition patterns of PM1 and PM2.5 in the human respiratory system were more severe compared to PM10. The ratio of concentration of PM2.5/PM10 mass and their respective chemical constituents decreased with rise in engine-operating loads. Increasing trends with loads were observed for fuel-based EF of EC and power-based EF of both OC and EC. The particulate acidity (both total acidity and in-situ acidity) increased with rise in engine-operating loads. The fate study through the environmental chamber revealed that initial concentrations of PM1, PM2.5, PM10, and O3 played a significant role in degradation of these gaseous pollutants to form secondary particulates from precursor gases of NO2, SO2, and VOCs. The ambient air study for PM2.5 inferred that the winter season was more critical in terms of primary emissions, secondary formation and occurrence of hazy days compared to three other seasons of the year. The higher emission of air pollutants coupled with meteorological factors was the reason for such trends of higher pollution loads during winter.