Characterization of carbonaceous fractions in PM2.5 and PM10 over a typical industrial city in central China

Abstract

Aerosol samples of PM and PM were collected every 6 days from March 2012 to February 2013 in Huangshi, a typical industrial city in central China, to investigate the characteristics, relationships, and sources of carbonaceous species. The PM and PM samples were analyzed for organic carbon (OC), elemental carbon (EC), char, and soot using the thermal/optical reflectance (TOR) method following the IMPROVE_A protocol. PM and PM concentrations ranged from 29.37 to 501.43 μg m and from 50.42 to 330.07 μg m, with average levels of 104.90 and 151.23 μg m, respectively. The 24-h average level of PM was about three times the US EPA standard of 35 μg m, and significantly exceeds the Class II National Air Quality Standard of China of 75 μg m. The seasonal cycles of PM mass and OC concentrations were higher during winter than in summer. EC and char concentrations were generally highest during winter but lowest in spring, while higher soot concentrations occurred in summer. This seasonal variation could be attributed to different seasonal meteorological conditions and changes in source contributions. Strong correlations between OC and EC were found for both PM and PM in winter and fall, while char and soot showed a moderate correlation in summer and winter. The average OC/EC ratios were 5.11 and 4.46 for PM and PM, respectively, with individual OC/EC ratios nearly always exceeding 2.0. Higher char/soot ratios during the four seasons indicated that coal combustion and biomass burning were the major sources for carbonaceous aerosol in Huangshi. Contrary to expectations, secondary organic carbon (SOC) which is estimated using the EC tracer method exhibited spring maximum and summer minimum, suggesting that photochemical activity is not a leading factor in the formation of secondary organic aerosols in the study area. The contribution of SOC to OC concentration for PM and PM were 47.33 and 45.38%, respectively, implying that SOC was an important component of OC mass. The serious air pollution in haze-fog episode was strongly correlated with the emissions of pollutants from biomass burning and the meteorological conditions.

Association between ambient air pollution exposure and infants small for gestational age in Huangshi, China: a cross-sectional study

“…To our knowledge, there are no existing studies that have investigated the relationship between air pollution and SGA in central China. Huangshi is an industrial city in central China, and its economic growth has been attributed to mining and metallurgy in recent years (Zhan et al 2017). Although the concentrations of air pollutants in Huangshi are lower than those in other industrial cities, such as Wuhan (Qian et al 2016), air pollution exposure in Huangshi is still relatively higher than the air quality guidelines (AQG) issued by the World Health Organization (WHO 2005).…”

Influence of Tropical Weather and Northeasterly Air Mass on Carbonaceous Aerosol in the Southern Malay Peninsula

“…Soot contains dominant polycyclic aromatic hydrocarbons, compounds containing oxygen (furans, benzofurans, and phenols), and compounds containing aliphatic nitrogen (benzonitrile). 1,60,63,64 Several studies have been conducted in Southeast Asia, Indochina, and India on the emission of char-EC and soot-EC from different sources. The studies found that low (∼1) char-EC/soot-EC ratios indicate the fuel combustion of transportation sectors and burning of grass, whereas high char-EC/soot-EC ratios reflect wood combustion, particularly biomass burning by smoldering at low temperature, in the study areas.…”

“…1,55,70,71 Ratios ranging from <1 to 1.6 are observed for fresh traffic emissions, 1,70 whereas ratios between 1 and 2 have been reported for urban sources. Ratios ranging from 2 to 5 indicate a coal combustion origin 1,55 and are assumed to indicate the considerable contribution of secondary aerosol sources. 70 High OC/EC ratios are indicative of secondary origins and processes that are influenced drastically by the contribution of secondary organic aerosols to the OC fraction.…”

Spatial Distribution, Source Apportionment, Ozone Formation Potential, and Health Risks of Volatile Organic Compounds over a Typical Central Plain City in China

“…However, studies of VOCs in China have focused on developed megacities. Researches on particulate matters for developing areas in China had been started [17][18][19], while for VOCs and O 3 control, data and studies are still leaving limited and far from sufficient [20].…”