scholarly journals Chemical Composition and Source Apportionment of PM2.5 in Urban Areas of Xiangtan, Central South China

2019 ◽  
Vol 16 (4) ◽  
pp. 539 ◽  
Author(s):  
Xiaoyao Ma ◽  
Zhenghui Xiao ◽  
Lizhi He ◽  
Zongbo Shi ◽  
Yunjiang Cao ◽  
...  
Keyword(s):  
Source Apportionment ◽  
South China ◽  
Urban Areas ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Vehicle Exhaust ◽  
Industrial Emissions ◽  
Wind Speeds

Xiangtan, South China, is characterized by year-round high relative humidity and very low wind speeds. To assess levels of PM2.5, daily samples were collected from 2016 to 2017 at two urban sites. The mass concentrations of PM2.5 were in the range of 30–217 µg/m3, with the highest concentrations in winter and the lowest in spring. Major water-soluble ions (WSIIs) and total carbon (TC) accounted for 58–59% and 21–24% of the PM2.5 mass, respectively. Secondary inorganic ions (SO42−, NO3−, and NH4+) dominated the WSIIs and accounted for 73% and 74% at the two sites. The concentrations of K, Fe, Al, Sb, Ca, Zn, Mg, Pb, Ba, As, and Mn in the PM2.5 at the two sites were higher than 40 ng/m3, and decreased in the order of winter > autumn > spring. Enrichment factor analysis indicates that Co, Cu, Zn, As, Se, Cd, Sb, Tl, and Pb mainly originates from anthropogenic sources. Source apportionment analysis showed that secondary inorganic aerosols, vehicle exhaust, coal combustion and secondary aerosols, fugitive dust, industrial emissions, steel industry are the major sources of PM2.5, contributing 25–27%, 21–22%, 19–21%, 16–18%, 6–9%, and 8–9% to PM2.5 mass.

scholarly journals Source Apportionment of Aerosols by 14C Measurements in Different Carbonaceous Particle Fractions

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 475-484 ◽  
Author(s):  
S Szidat ◽  
T M Jenk ◽  
H W Gäggeler ◽  
H-A Synal ◽  
R Fisseha ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Source Apportionment ◽  
Atmospheric Aerosols ◽  
Elemental Carbon ◽  
Water Soluble ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Ambient Aerosols ◽  
Carbonaceous Particle ◽  
Fossil Carbon

Radiocarbon enables a distinction between contemporary and fossil carbon, which can be used for the apportionment of biogenic and anthropogenic sources in environmental studies. In order to apply this approach to carbonaceous atmospheric aerosols, it is necessary to adapt pretreatment procedures to the requirements of 14C measurements. In this work, we followed an approach in which total carbon (TC) is subdivided into fractions of different chemical and physical properties. 14C data of ambient aerosols from Zürich (Switzerland) are presented for the 2 sub-fractions of TC, organic carbon (OC) and elemental carbon (EC). Furthermore, OC is separated into water-insoluble OC (WINSOC) and water-soluble OC (WSOC). Results demonstrate the importance to differentiate between these fractions for 14C-deduced source apportionment, as the contributions can range between both extremes, nearly exclusively biogenic and anthropogenic.

scholarly journals Source apportionment of PM<sub>2.5</sub> in Shanghai based on hourly organic molecular markers and other source tracers

2020 ◽  
Vol 20 (20) ◽  
pp. 12047-12061
Author(s):  
Rui Li ◽  
Qiongqiong Wang ◽  
Xiao He ◽  
Shuhui Zhu ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Secondary Source ◽  
Vehicle Exhaust ◽  
Industrial Emission ◽  
Episodic Evolution ◽  
Hourly Data

Abstract. Identification of various emission sources and quantification of their contributions comprise an essential step in formulating scientifically sound pollution control strategies. Most previous studies have been based on traditional offline filter analysis of aerosol major components (usually inorganic ions, elemental carbon – EC, organic carbon – OC, and elements). In this study, source apportionment of PM2.5 using a positive matrix factorization (PMF) model was conducted for urban Shanghai in the Yangtze River Delta region, China, utilizing a large suite of molecular and elemental tracers, together with water-soluble inorganic ions, OC, and EC from measurements conducted at two sites from 9 November to 3 December 2018. The PMF analysis with inclusion of molecular makers (i.e., MM-PMF) identified 11 pollution sources, including 3 secondary-source factors (i.e., secondary sulfate; secondary nitrate; and secondary organic aerosol, SOA, factors) and 8 primary sources (i.e., vehicle exhaust, industrial emission and tire wear, industrial emission II, residual oil combustion, dust, coal combustion, biomass burning, and cooking). The secondary sources contributed 62.5 % of the campaign-average PM2.5 mass, with the secondary nitrate factor being the leading contributor. Cooking was a minor contributor (2.8 %) to PM2.5 mass while a significant contributor (11.4 %) to the OC mass. Traditional PMF analysis relying on major components alone (PMFt) was unable to resolve three organics-dominated sources (i.e., biomass burning, cooking, and SOA source factors). Utilizing organic tracers, the MM-PMF analysis determined that these three sources combined accounted for 24.4 % of the total PM2.5 mass. In PMFt, this significant portion of PM mass was apportioned to other sources and thereby was notably biasing the source apportionment outcome. Backward trajectory and episodic analysis were performed on the MM-PMF-resolved source factors to examine the variations in source origins and composition. It was shown that under all episodes, secondary nitrate and the SOA factor were two major source contributors to the PM2.5 pollution. Our work has demonstrated that comprehensive hourly data of molecular markers and other source tracers, coupled with MM-PMF, enables examination of detailed pollution source characteristics, especially organics-dominated sources, at a timescale suitable for monitoring episodic evolution and with finer source breakdown.

scholarly journals Source apportionment and dynamic changes of carbonaceous aerosols during the haze bloom–decay process in China based on radiocarbon and organic molecular tracers

2015 ◽  
Vol 15 (23) ◽  
pp. 34949-34979 ◽  
Author(s):  
J. Liu ◽  
J. Li ◽  
D. Liu ◽  
P. Ding ◽  
C. Shen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
South China ◽  
Fossil Fuel ◽  
Decay Process ◽  
Water Soluble ◽  
Total Carbon ◽  
Carbonaceous Aerosols ◽  
Fossil Carbon

Abstract. Fine carbonaceous aerosols (CAs) is the key factor influencing the currently filthy air in megacities of China, yet seldom study simultaneously focuses on the origins of different CAs species using specific and powerful source tracers. Here, we present a detailed source apportionment for various CAs fractions, including organic carbon (OC), water-soluble OC (WSOC), water-insoluble OC (WIOC), elemental carbon (EC) and secondary OC (SOC) in the largest cities of North (Beijing, BJ) and South China (Guangzhou, GZ), respectively, using the measurements of radiocarbon and anhydrosugars. Results show that non-fossil fuel sources such as biomass burning and biogenic emission make a significant contribution to the total CAs in Chinese megacities: 56 ± 4 % in BJ and 46 ± 5 % in GZ, respectively. The relative contributions of primary fossil carbon from coal and liquid petroleum combustions, primary non-fossil carbon and secondary organic carbon (SOC) to total carbon are 19, 28 and 54 % in BJ, and 40, 15 and 46 % in GZ, respectively. Non-fossil fuel sources account for 52 % in BJ and 71 % in GZ of SOC, respectively. These results suggest that biomass burning has a greater influence on regional particulate air pollution in North China than in South China. We observed an unabridged haze bloom–decay process in South China, which illustrates that both primary and secondary matter from fossil sources played a key role in the blooming phase of the pollution episode, while haze phase is predominantly driven by fossil-derived secondary organic matter and nitrate.

scholarly journals Water-soluble iron emitted from vehicle exhaust is linked to primary speciated organic compounds

2020 ◽  
Vol 20 (3) ◽  
pp. 1849-1860 ◽  
Author(s):  
Joseph R. Salazar ◽  
Benton T. Cartledge ◽  
John P. Haynes ◽  
Rachel York-Marini ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Urban Areas ◽  
Transition Element ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Vehicle Exhaust ◽  
Edge Structure ◽  
Iron Solubility ◽  
Soluble Iron ◽  
Low Emission

Abstract. Iron is the most abundant transition element in airborne particulate matter (PM), primarily existing as Fe(II) or Fe(III). Generally, the fraction of water-soluble iron is greater in urban areas compared to areas dominated by crustal emissions. To better understand the origin of water-soluble iron in urban areas, tailpipe emission samples were collected from 32 vehicles with emission certifications of Tier 0 low emission vehicles (LEV I), Tier 2 low emission vehicles (LEV II), ultralow emission vehicles (ULEVs), super-ultralow emission vehicles (SULEVs), and partial-zero emission vehicles (PZEVs). The components quantified included gases, inorganic ions, elemental carbon (EC), organic carbon (OC), total metals, and water-soluble metals. Naphthalene and intermediate-volatility organic compounds (IVOCs) were quantified for a subset of vehicles. The IVOCs quantified contained 12 to 18 carbons and were divided into three subgroups: aliphatic, single-ring aromatic (SRA), and polar (material not classified as either aliphatic or SRA). Iron solubility in the tested vehicles ranged from 0 % to 82 % (average 30 %). X-ray absorption near-edge structure (XANES) spectroscopy showed that Fe(III) was the primary oxidation state in 14 of the 16 tested vehicles, confirming that the presence of Fe(II) was not the main driver of water-soluble Fe. The correlation of water-soluble iron with sulfate was insignificant, as was correlation with every chemical component except naphthalene and some C12–C18 IVOCs with R2 values as high as 0.56. A controlled benchtop study confirmed that naphthalene alone increases iron solubility from soils by a factor of 5.5 and that oxidized naphthalene species are created in the extract solution. These results suggest that the large driver in water-soluble iron from primary vehicle tailpipe emissions is related to the organic composition of the PM. We hypothesize that, during the extraction process, specific components of the organic fraction of the PM are oxidized and chelate the iron into water.

scholarly journals Source apportionment and dynamic changes of carbonaceous aerosols during the haze bloom-decay process in China based on radiocarbon and organic molecular tracers

2016 ◽  
Vol 16 (5) ◽  
pp. 2985-2996 ◽  
Author(s):  
Junwen Liu ◽  
Jun Li ◽  
Di Liu ◽  
Ping Ding ◽  
Chengde Shen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
South China ◽  
Fossil Fuel ◽  
Decay Process ◽  
Water Soluble ◽  
Total Carbon ◽  
Carbonaceous Aerosols ◽  
Fossil Carbon

Abstract. Fine carbonaceous aerosols (CAs) is the key factor influencing the currently filthy air in megacities in China, yet few studies simultaneously focus on the origins of different CAs species using specific and powerful source tracers. Here, we present a detailed source apportionment for various CAs fractions, including organic carbon (OC), water-soluble OC (WSOC), water-insoluble OC (WIOC), elemental carbon (EC) and secondary OC (SOC) in the largest cities of North (Beijing, BJ) and South China (Guangzhou, GZ), using the measurements of radiocarbon and anhydrosugars. Results show that non-fossil fuel sources such as biomass burning and biogenic emission make a significant contribution to the total CAs in Chinese megacities: 56 ± 4 in BJ and 46 ± 5 % in GZ, respectively. The relative contributions of primary fossil carbon from coal and liquid petroleum combustions, primary non-fossil carbon and secondary organic carbon (SOC) to total carbon are 19, 28 and 54 % in BJ, and 40, 15 and 46 % in GZ, respectively. Non-fossil fuel sources account for 52 in BJ and 71 % in GZ of SOC, respectively. These results suggest that biomass burning has a greater influence on regional particulate air pollution in North China than in South China. We observed an unabridged haze bloom-decay process in South China, which illustrates that both primary and secondary matter from fossil sources played a key role in the blooming phase of the pollution episode, while haze phase is predominantly driven by fossil-derived secondary organic matter and nitrate.

scholarly journals Water-soluble iron correlation to primary speciated organics in low-emitting vehicle exhaust

2019 ◽  
Author(s):  
Joseph R. Salazar ◽  
Benton T. Cartledge ◽  
John P. Haynes ◽  
Rachel York-Marini ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Urban Areas ◽  
Transition Element ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Vehicle Exhaust ◽  
Edge Structure ◽  
Iron Solubility ◽  
Soluble Iron ◽  
Tail Pipe ◽  
Low Emission

Abstract. Iron is the most abundant transition element in airborne PM, primarily existing as Fe(II) or Fe(III). Generally, the fraction of water-soluble iron is greater in urban areas compared to areas dominated by crustal emissions. To better understand the origin of water-soluble iron in urban areas, tail-pipe emission samples were collected from 32 vehicles with emission certifications of Tier 0, low emission vehicles (LEV I), tier two low emission vehicles (LEV II), ultralow emission vehicles (ULEV), superultra-low emission vehicles (SULEV), and partial-zero emission vehicles (PZEV). Components quantified included gases, inorganic ions, EC/OC, total metals and water-soluble metals. In addition, naphthalene and various classes of C12–C18 intermediate volatility organic compounds (IVOC) were quantified for a subset of vehicles: aliphatic, single ring aromatic (SRA), and polar (material not classified as either aliphatic or SRA). Iron solubility in the tested vehicles ranged from 0–82 % (average = 30 %). X-ray absorption near edge structure (XANES) spectroscopy showed that Fe(III) was the primary oxidation state in 14 of the 16 tested vehicles, confirming that the presence of Fe(II) was not the main driver of water-soluble Fe. Correlation of water-soluble iron to sulfate was insignificant, as was correlation to every chemical component, except to naphthalene and some C12–C18 IVOCs with R2 values as high as 0.56. A controlled benchtop study confirmed that naphthalene, alone, increases iron solubility from soils by a factor of 5.5 and that oxidized naphthalene species are created in the extract solution. These results suggest that the large driver in water-soluble iron from primary vehicle tail-pipe emissions is related to the organic composition of the PM, indicating the organic fraction of the PM influences the behavior and solubility of iron.

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

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1365
Author(s):  
Kun He ◽  
Zhenxing Shen ◽  
Jian Sun ◽  
Yali Lei ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Source Apportionment ◽  
Organic Compounds ◽  
Health Risks ◽  
Urban Areas ◽  
High Time Resolution ◽  
Ozone Formation ◽  
Industrial Site ◽  
Industrial Emissions ◽  
Volatile Organic

The profiles, contributions to ozone formation, and associated health risks of 56 volatile organic compounds (VOCs) species were investigated using high time resolution observations from photochemical assessment monitoring stations (PAMs) in Luoyang, China. The daily averaged concentration of total VOCs (TVOCs) was 21.66 ± 10.34 ppbv in urban areas, 14.45 ± 7.40 ppbv in suburbs, and 37.58 ± 13.99 ppbv in an industrial zone. Overall, the VOCs levels in these nine sites followed a decreasing sequence of alkanes > aromatics > alkenes > alkyne. Diurnal variations in VOCs exhibited two peaks at 8:00–9:00 and 19:00–20:00, with one valley at 23:00–24:00. Source apportionment indicated that vehicle and industrial emissions were the dominant sources of VOCs in urban and suburban sites. The industrial site displayed extreme levels, with contributions from petrochemical-related sources of up to 38.3%. Alkenes and aromatics displayed the highest ozone formation potentials because of their high photochemical reactivity. Cancer and noncancer risks in the industrial site were higher than those in the urban and suburban areas, and USEPA possible risk thresholds were reached in the industrial site, indicating PAMs VOC–related health problems cannot be ignored. Therefore, vehicle and industrial emissions should be prioritized when considering VOCs and O3 control strategies in Luoyang.

scholarly journals Carbonaceous components, levoglucosan and inorganic ions in tropical aerosols from Tanzania, East Africa: implication for biomass burning contribution to organic aerosols

2012 ◽  
Vol 12 (11) ◽  
pp. 28661-28703 ◽  
Author(s):  
S. L. Mkoma ◽  
K. Kawamura ◽  
P. Fu
Keyword(s):  
Organic Carbon ◽  
East Africa ◽  
Biomass Burning ◽  
Inorganic Ions ◽  
Ionic Species ◽  
Water Soluble ◽  
Total Carbon ◽  
Rural Site ◽  
Wet Season ◽  
Pm2.5 And Pm10

Abstract. Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania in 2011 during wet and dry seasons and they were analysed for carbonaceous components, levoglucosan and water-soluble inorganic ions. The mean mass concentrations of PM2.5 and PM10 were 28.2&amp;pm;6.4 μg m−3 and 47&amp;pm;8.2 μg m−3 in wet season, and 39.1&amp;pm;9.8 μg m−3 and 61.4&amp;pm;19.2 μg m−3 in dry season, respectively. Total carbon (TC) accounted for 16–19% of the PM2.5 mass and 13–15% of the PM10 mass. On average, 85.9 to 88.7% of TC in PM2.5 and 87.2 to 90.1% in PM10 was organic carbon (OC), of which 67–72% and 63% was found to be water-soluble organic carbon (WSOC) in PM2.5 and PM10, respectively. Water-soluble potassium (K+) and sulphate (SO42−) in PM2.5 and, sodium (Na+) and SO42− in PM10 were the dominant ionic species. We found, that concentrations of biomass burning tracers (levoglucosan and mannosan) well correlated with non-sea-salt-K+, WSOC and OC in the aerosols from Tanzania, East Africa. Mean contributions of levoglucosan to OC ranged between 3.9–4.2% for PM2.5 and 3.5–3.8% for PM10. This study demonstrates that emissions from biomass- and biofuel-burning activities followed by atmospheric photochemical processes mainly control the air quality in Tanzania.

scholarly journals Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

2011 ◽  
Vol 11 (6) ◽  
pp. 16369-16416 ◽  
Author(s):  
K. E. Yttri ◽  
D. Simpson ◽  
J. K. Nøjgaard ◽  
K. Kristensen ◽  
J. Genberg ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Fossil Fuel ◽  
Late Summer ◽  
Latin Hypercube Sampling ◽  
Total Carbon ◽  
Carbonaceous Aerosol ◽  
Anthropogenic Sources ◽  
Minor Variation ◽  
Rural Background ◽  
Summer Time

Abstract. In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 collected at four Nordic rural background sites (Birkenes (Norway), Hyytiälä (Finland) Vavihill (Sweden), Lille Valby (Denmark)) during late summer (5 August–2 September 2009). Levels of source specific tracers, i.e. cellulose, levoglucosan, mannitol and the 14C/12C ratio of total carbon (TC), have been used as input for source apportionment of the carbonaceous aerosol, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting from this approach. The carbonaceous aerosol (here: TCp; i.e. particulate TC) was totally dominated by natural sources (69–86 %), with biogenic secondary organic aerosol (BSOA) being the single most important source (48–57 %). Interestingly, primary biological aerosol particles (PBAP) were the second most important source (20–32 %). The anthropogenic contribution was mainly attributed to fossil fuel sources (OCff and ECff (10–24 %), whereas no more than 3–7 % was explained by combustion of biomass (OCbb and ECbb in this late summer campaign i.e. emissions from residential wood burning and/or wild/agricultural fires. Fossil fuel sources totally dominated the ambient EC loading, accounting for 4–12 % of TCp, whereas <1.5 % was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyytiälä and Birkenes showed greater resemblance to each other, as did Lille Valby and Vavihill, the two latter being somewhat more influenced by anthropogenic sources. Ambient levels of organosulphates and nitrooxy-organosulphates in the Nordic rural background environment are reported for the first time in the present study. The most abundant organosulphate compounds were an organosulphate of isoprene and nitrooxy-organosulphates of α- and β-pinene and limonene.

scholarly journals Source apportionment of carbonaceous aerosol in southern Sweden

2011 ◽  
Vol 11 (22) ◽  
pp. 11387-11400 ◽  
Author(s):  
J. Genberg ◽  
M. Hyder ◽  
K. Stenström ◽  
R. Bergström ◽  
D. Simpson ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Source Apportionment ◽  
Fossil Fuels ◽  
Elemental Carbon ◽  
Transport Model ◽  
Total Carbon ◽  
Carbonaceous Aerosol ◽  
Anthropogenic Sources ◽  
Biomass Combustion ◽  
Southern Sweden

Abstract. A one-year study was performed at the Vavihill background station in southern Sweden to estimate the anthropogenic contribution to the carbonaceous aerosol. Weekly samples of the particulate matter PM10 were collected on quartz filters, and the amounts of organic carbon, elemental carbon, radiocarbon (14C) and levoglucosan were measured. This approach enabled source apportionment of the total carbon in the PM10 fraction using the concentration ratios of the sources. The sources considered in this study were emissions from the combustion of fossil fuels and biomass, as well as biogenic sources. During the summer, the carbonaceous aerosol mass was dominated by compounds of biogenic origin (80%), which are associated with biogenic primary and secondary organic aerosols. During the winter months, biomass combustion (32%) and fossil fuel combustion (28%) were the main contributors to the carbonaceous aerosol. Elemental carbon concentrations in winter were about twice as large as during summer, and can be attributed to biomass combustion, probably from domestic wood burning. The contribution of fossil fuels to elemental carbon was stable throughout the year, although the fossil contribution to organic carbon increased during the winter. Thus, the organic aerosol originated mainly from natural sources during the summer and from anthropogenic sources during the winter. The result of this source apportionment was compared with results from the EMEP MSC-W chemical transport model. The model and measurements were generally consistent for total atmospheric organic carbon, however, the contribution of the sources varied substantially. E.g. the biomass burning contributions of OC were underestimated by the model by a factor of 2.2 compared to the measurements.

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