Cefpiramide Sodium

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.

Condensable particulate matter (CPM) and filterable particulate matter (FPM) emitted from industrial sources have been well studied, but their emissions from vehicles have not yet been covered. This study explores the emission characteristics of CPM and FPM from typical diesel vehicles under various driving conditions. The emission factors (EFs) of CPMs under driving conditions were 5.4-10.4 times higher than those of FPMs, while CPMs EFs under transient driving conditions were about 2.5 times higher than those under steady driving conditions. CPM and FPM are mainly composed of organic matter accounting for 53.3 %-92.9 %, while the intermediate and semi-volatile organic compounds dominate the organic matter accounting for 86.3 %-98.6 %. Similar to industrial sources, alkanes are the predominant organic species emitted by diesel vehicles, comprising 42.0 %-64.0 % of the detected organic components. Inorganic CPM is primarily composed of NH₄⁺ , representing 84.9 %-87.6 % of the total, in contrast to industrial sources where SO₄^2- and Cl^- dominate. Interestingly, the air pollution control devices installed on diesel vehicles under steady driving conditions perform better in removing organic CPM and producing higher inorganic CPM emissions than those under transient driving conditions. These findings will enhance the comprehensive understanding of particulate matter emitted from diesel vehicles and provide a scientific foundation for the development of related control technologies.