Study of condensable particulate matter from stationary combustion sources: Source profiles, emissions, and impact on...

Although significant progress has been made in controlling emissions from stationary combustion sources in China over the past decade, understanding of condensable particulate matter (CPM) emissions from these sources and their impact on ambient PM_2.5 remains limited. In this study, we established the source profiles and emission inventories of CPM from coal-fired industrial boilers (CFIBs), coal-fired power plants (CFPPs), and iron and steel industry (ISIs) for the Yangtze River Delta (YRD) region of China; furthermore, the air quality model (Community Multiscale Air Quality, CMAQ) was used to evaluate the impact of CPM emissions from these three types of stationary combustion sources on ambient PM_2.5 during Feb. 2018, a month characterized by elevated PM_2.5 concentrations. The results indicated that CPM emissions from these three sources in the YRD region before and after the implementation of the ultra-low emissions (ULE) policy amounted to 109,839 and 43,338 tons, respectively, with particularly high emission intensity along the Yangtze River. The implementation of CFPPs ULE policy was shown to reduce the impact of CPM emissions from these three stationary sources on monthly PM_2.5 concentrations from 0.92 μg/m³ to 0.41 μg/m³ (with a maximum of 5.35 μg/m³). This reduction exceeded the 0.31 μg/m³ decrease in PM_2.5 concentrations resulting from the emission reductions of conventional pollutants (FPM, SO₂ and NOx). CPM emissions from these three stationary sources were found to increase the PM_2.5 by 0.68 μg/m³ during pollution periods. The largest components of PM_2.5 contributed by CPM emissions from stationary combustion sources were sulfate, organic carbon, and nitrate, accounting for 21.4 %, 21.1 %, and 18.2 %, respectively. Particularly, contributions from CPM emissions to PM_2.5 varied by altitude, with a relatively large impact at altitudes between 220 and 460 m. Attention should be given to CPM emission control, with particular priority placed on implementing ULE measures for ISIs and CFIBs.