scholarly journals Source apportionment of PM<sub>2.5</sub> at a regional background site in North China using PMF linked with radiocarbon analysis: insight into the contribution of biomass burning

2016 ◽  
Vol 16 (17) ◽  
pp. 11249-11265 ◽  
Author(s):  
Zheng Zong ◽  
Xiaoping Wang ◽  
Chongguo Tian ◽  
Yingjun Chen ◽  
Lin Qu ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Biomass Burning ◽  
Coal Combustion ◽  
North China ◽  
Fine Particles ◽  
Vehicle Emission ◽  
Shandong Peninsula ◽  
Air Masses ◽  
Background Site ◽  
Bth Region

Abstract. Source apportionment of fine particles (PM2.5) at a background site in North China in the winter of 2014 was done using statistical analysis, radiocarbon (14C) measurement and positive matrix factorization (PMF) modeling. Results showed that the concentration of PM2.5 was 77.6 ± 59.3 µg m−3, of which sulfate (SO42−) concentration was the highest, followed by nitrate (NO3−), organic carbon (OC), elemental carbon (EC) and ammonium (NH4+). As demonstrated by backward trajectory, more than half of the air masses during the sampling period were from the Beijing–Tianjin–Hebei (BTH) region, followed by Mongolia and the Shandong Peninsula. Cluster analysis of chemical species suggested an obvious signal of biomass burning in the PM2.5 from the Shandong Peninsula, while the PM2.5 from the BTH region showed a vehicle emission pattern. This finding was further confirmed by the 14C measurement of OC and EC in two merged samples. The 14C result indicated that biogenic and biomass burning emission contributed 59 ± 4 and 52 ± 2 % to OC and EC concentrations, respectively, when air masses originated from the Shandong Peninsula, while the contributions fell to 46 ± 4 and 38 ± 1 %, respectively, when the prevailing wind changed and came from the BTH region. The minimum deviation between source apportionment results from PMF and 14C measurement was adopted as the optimal choice of the model exercises. Here, two minor overestimates with the same range (3 %) implied that the PMF result provided a reasonable source apportionment of the regional PM2.5 in this study. Based on the PMF modeling, eight sources were identified; of these, coal combustion, biomass burning and vehicle emission were the main contributors of PM2.5, accounting for 29.6, 19.3 and 15.9 %, respectively. Compared with overall source apportionment, the contributions of vehicle emission, mineral dust, coal combustion and biomass burning increased when air masses came from the BTH region, Mongolia and the Shandong Peninsula, respectively. Since coal combustion and vehicle emission have been considered as the leading emission sources to be controlled for improving air quality, biomass burning was highlighted in the present study.

scholarly journals Biomass burning contribution to regional PM<sub>2.5</sub> during winter in the North China

2016 ◽  
Author(s):  
Zheng Zong ◽  
Xiaoping Wang ◽  
Chongguo Tian ◽  
Yingjun Chen ◽  
Lin Qu ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Biomass Burning ◽  
Coal Combustion ◽  
North China ◽  
Fine Particles ◽  
Vehicle Emission ◽  
Shandong Peninsula ◽  
Air Masses ◽  
The North ◽  
Bth Region

Abstract. Source apportionment of fine particles (PM2.5) at a background site in the North China in winter, 2014 was assessed by statistical analysis on the chemical species grouped by the trajectory clusters, radiocarbon (14C) measurement and the Positive Matrix Factorization (PMF) modeling linked with the 14C measurement. During the sampling period, the concentration of PM2.5 was 77.6 ± 59.3 μg m−3, and the sulfate concentration was the highest, followed by nitrate, organic carbon (OC), elemental carbon (EC) and ammonium, respectively. Demonstrated by the backward trajectory, more than half of PM2.5 was found from the Beijing-Tianjin-Hebei (BTH) region, followed by the Mongolia and the Shandong Peninsula. The cluster analysis showed that PM2.5 from the Shandong Peninsula had an obvious signal of biomass burning emission, while that from the BTH region showed vehicle emission pattern. The finding was further confirmed by the radiocarbon measurement of OC and EC in two merged samples selected from a successive synoptic process. The 14C measurement indicated that biogenic and biomass burning emission contributed 59 % and 52 % to OC and EC concentrations when air masses originated from the Shandong Peninsula, and the contributions fell to 46 % and 38 %, respectively, when the prevailing wind changed and came from the BTH region. In addition, minimum deviation of the source apportionments from PMF results and 14C measurement was used as the optimal choice of the model exercises. Here, two minor overestimations with the same range (3 %) suggested that the PMF results provided a reasonable source apportionment of regional PM2.5 in the North China during winter. Based on the results above, eight main sources were identified, of which, coal combustion, biomass burning and vehicle emissions were the largest contributors of PM2.5, accounting for 29.6 %, 19.3 % and 15.8 %, respectively. Compared with the overall source apportionment, the contribution of vehicle emission increased slightly when air masses came from the BTH region, the contribution of mineral dust and coal combustion rose obviously when air masses were from the Mongolia with high speed, and biomass burning became the dominant contributor when air masses carried from the Shandong Peninsula. As the largest contributor to PM2.5 in winter of North China, coal combustion has been identified as the most leading emission sector to be controlled for improving the air quality by the government. Vehicle emission contributed significantly to the PM2.5 levels in the BTH region, which has also been considered to control as the second major emission sector. Biomass burning emission was highlighted in the present study because of its dominant contribution to PM2.5 burden in the Shandong Peninsula. Some suggests were provided to wake farmers from agricultural residue burning in household and field.

scholarly journals Source apportionment of fine organic carbon at an urban site of Beijing using a chemical mass balance model

2021 ◽  
Vol 21 (9) ◽  
pp. 7321-7341
Author(s):  
Jingsha Xu ◽  
Di Liu ◽  
Xuefang Wu ◽  
Tuan V. Vu ◽  
Yanli Zhang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Mass Balance ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Coal Combustion ◽  
Fine Particles ◽  
Inorganic Ions ◽  
Balance Model ◽  
Urban Site ◽  
Chemical Mass Balance

Abstract. Fine particles were sampled from 9 November to 11 December 2016 and 22 May to 24 June 2017 as part of the Atmospheric Pollution and Human Health in a Chinese Megacity (APHH-China) field campaigns in urban Beijing, China. Inorganic ions, trace elements, organic carbon (OC), elemental carbon (EC), and organic compounds, including biomarkers, hopanes, polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and fatty acids, were determined for source apportionment in this study. Carbonaceous components contributed on average 47.2 % and 35.2 % of total reconstructed PM2.5 during the winter and summer campaigns, respectively. Secondary inorganic ions (sulfate, nitrate, ammonium; SNA) accounted for 35.0 % and 45.2 % of total PM2.5 in winter and summer. Other components including inorganic ions (K+, Na+, Cl−), geological minerals, and trace metals only contributed 13.2 % and 12.4 % of PM2.5 during the winter and summer campaigns. Fine OC was explained by seven primary sources (industrial and residential coal burning, biomass burning, gasoline and diesel vehicles, cooking, and vegetative detritus) based on a chemical mass balance (CMB) receptor model. It explained an average of 75.7 % and 56.1 % of fine OC in winter and summer, respectively. Other (unexplained) OC was compared with the secondary OC (SOC) estimated by the EC-tracer method, with correlation coefficients (R2) of 0.58 and 0.73 and slopes of 1.16 and 0.80 in winter and summer, respectively. This suggests that the unexplained OC by the CMB model was mostly associated with SOC. PM2.5 apportioned by the CMB model showed that the SNA and secondary organic matter were the two highest contributors to PM2.5. After these, coal combustion and biomass burning were also significant sources of PM2.5 in winter. The CMB results were also compared with results from the positive matrix factorization (PMF) analysis of co-located aerosol mass spectrometer (AMS) data. The CMB model was found to resolve more primary organic aerosol (OA) sources than AMS-PMF, but the latter could apportion secondary OA sources. The AMS-PMF results for major components, such as coal combustion OC and oxidized OC, correlated well with the results from the CMB model. However, discrepancies and poor agreements were found for other OC sources, such as biomass burning and cooking, some of which were not identified in AMS-PMF factors.

scholarly journals Source Apportionment of Fine Aerosol at an Urban Site of Beijing using a Chemical Mass Balance Model

2020 ◽  
Author(s):  
Jingsha Xu ◽  
Di Liu ◽  
Xuefang Wu ◽  
Tuan V. Vu ◽  
Yanli Zhang ◽  
...  
Keyword(s):  
Mass Balance ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Coal Combustion ◽  
Fine Particles ◽  
Correlation Coefficients ◽  
Inorganic Ions ◽  
Balance Model ◽  
Urban Site ◽  
Chemical Mass Balance

Abstract. Fine particles were sampled from 9th November to 11th December 2016 and 22nd May to 24th June 2017 as part of the Atmospheric Pollution and Human Health in a Chinese megacity (APHH-China) field campaigns in urban Beijing, China. Inorganic ions, trace elements, OC, EC, and organic compounds including biomarkers, hopanes, PAHs, n-alkanes and fatty acids, were determined for source apportionment in this study. Carbonaceous components contributed on average 47.2 % and 35.2 % of total reconstructed PM2.5 during the winter and summer campaigns, respectively. Secondary inorganic ions (sulfate, nitrate, ammonium; SNA) accounted for 35.0 % and 45.2 % of total PM2.5 in winter and summer. Other components including inorganic ions (K+, Na+, Cl−), geological minerals, and trace metals only contributed 13.2 % and 12.4 % of PM2.5 during the winter and summer campaigns. Fine OC was explained by seven primary sources (industrial/residential coal burning, biomass burning, gasoline/diesel vehicles, cooking and vegetative detritus) based on a chemical mass balance (CMB) receptor model. It explained an average of 75.7 % and 56.1 % of fine OC in winter and summer, respectively. Other (unexplained) OC was compared with the secondary OC (SOC) estimated by the EC-tracer method, with correlation coefficients (R2) of 0.58 and 0.73, and slopes of 1.16 and 0.80 in winter and summer, respectively. This suggests that the unexplained OC by CMB was mostly associated with SOC. PM2.5 apportioned by CMB showed that the SNA and secondary organic matter were the highest two contributors to PM2.5. After these, coal combustion and biomass burning were also significant sources of PM2.5 in winter. The CMB results were also compared with results from Positive Matrix Factorization (PMF) analysis of co-located Aerosol Mass Spectrometer (AMS) data. The CMB was found to resolve more primary OA sources than AMS-PMF but the latter apportioned more secondary OA sources. The AMS-PMF results for major components, such as coal combustion OC and oxidized OC correlated well with the results from CMB. However, discrepancies and poor agreements were found for other OC sources, such as biomass burning and cooking, some of which were not identified in AMS-PMF factors.

scholarly journals PMF and PSCF based source apportionment of PM2.5 at a regional background site in North China

2018 ◽  
Vol 203 ◽  
pp. 207-215 ◽  
Author(s):  
Zheng Zong ◽  
Xiaoping Wang ◽  
Chongguo Tian ◽  
Yingjun Chen ◽  
Shanfei Fu ◽  
...  
Keyword(s):  
Source Apportionment ◽  
North China ◽  
Background Site ◽  
Regional Background

scholarly journals Mixing state, composition, and sources of fine aerosol particles in the Qinghai-Tibetan Plateau and the influence of agricultural biomass burning

2015 ◽  
Vol 15 (17) ◽  
pp. 24369-24401 ◽  
Author(s):  
W. J. Li ◽  
S. R. Chen ◽  
Y. S. Xu ◽  
X. C. Guo ◽  
Y. L. Sun ◽  
...  
Keyword(s):  
Fly Ash ◽  
Tibetan Plateau ◽  
Biomass Burning ◽  
Coal Combustion ◽  
Fine Particles ◽  
Aerosol Particles ◽  
Microscopic Analysis ◽  
Organic Coating ◽  
Pollution Level ◽  
Mixing State

Abstract. Transmission electron microscopy (TEM) was employed to obtain morphology, size, composition, and mixing state of background fine particles with diameter less than 1 μm in the Qinghai-Tibetan Plateau (QTP) during 15 September to 15 October 2013. Individual aerosol particles mainly contained secondary inorganic aerosols (SIA-sulfate and nitrate) and organics during clean periods (PM2.5: particles less than 2.5 μg m−3). The presence of KCl-NaCl associated with organics and an increase of soot particles suggest that an intense biomass burning event caused the highest PM2.5 concentrations (> 30 μg m−3) during the study. A large number fraction of the fly ash-containing particles (21.73 %) suggests that coal combustion emissions in the QTP significantly contributed to air pollutants at the median pollution level (PM2.5: 10–30 μg m−3). We concluded that emissions from biomass burning and from coal combustion both constantly contribute to anthropogenic particles in the QTP atmosphere. Based on size distributions of individual particles in different pollution levels, we found that gas condensation on existing particles is an important chemical process for the formation of SIA with organic coating. TEM observations show that refractory aerosols (e.g., soot, fly ash, and visible organic particles) likely adhere to the surface of SIA particles larger than 200 nm due to coagulation. Organic coating and soot on surface of the aged particles likely influence their hygroscopic and optical properties in the QTP, respectively. To our knowledge, this study reports the first microscopic analysis of fine particles in the background QTP air.

scholarly journals Source apportionment of carbonaceous aerosols in Beijing with radiocarbon and organic tracers: insight into the differences between urban and rural sites

2021 ◽  
Vol 21 (10) ◽  
pp. 8273-8292
Author(s):  
Siqi Hou ◽  
Di Liu ◽  
Jingsha Xu ◽  
Tuan V. Vu ◽  
Xuefang Wu ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Biomass Burning ◽  
Fine Particles ◽  
Water Soluble ◽  
Carbonaceous Aerosol ◽  
Balance Model ◽  
Gas Chromatography Mass Spectrometry ◽  
Urban Site ◽  
Carbonaceous Aerosols ◽  
Carbonaceous Particles

Abstract. Carbonaceous aerosol is a dominant component of fine particles in Beijing. However, it is challenging to apportion its sources. Here, we applied a newly developed method which combined radiocarbon (14C) with organic tracers to apportion the sources of fine carbonaceous particles at an urban (IAP) and a rural (PG) site of Beijing. PM2.5 filter samples (24 h) were collected at both sites from 10 November to 11 December 2016 and from 22 May to 24 June 2017. 14C was determined in 25 aerosol samples (13 at IAP and 12 at PG) representing low pollution to haze conditions. Biomass burning tracers (levoglucosan, mannosan, and galactosan) in the samples were also determined using gas chromatography–mass spectrometry (GC-MS). Higher contributions of fossil-derived OC (OCf) were found at the urban site. The OCf / OC ratio decreased in the summer samples (IAP: 67.8 ± 4.0 % in winter and 54.2 ± 11.7 % in summer; PG: 59.3 ± 5.7 % in winter and 50.0 ± 9.0 % in summer) due to less consumption of coal in the warm season. A novel extended Gelencsér (EG) method incorporating the 14C and organic tracer data was developed to estimate the fossil and non-fossil sources of primary and secondary OC (POC and SOC). It showed that fossil-derived POC was the largest contributor to OC (35.8 ± 10.5 % and 34.1 ± 8.7 % in wintertime for IAP and PG, 28.9 ± 7.4 % and 29.1 ± 9.4 % in summer), regardless of season. SOC contributed 50.0 ± 12.3 % and 47.2 ± 15.5 % at IAP and 42.0 ± 11.7 % and 43.0 ± 13.4 % at PG in the winter and summer sampling periods, respectively, within which the fossil-derived SOC was predominant and contributed more in winter. The non-fossil fractions of SOC increased in summer due to a larger biogenic component. Concentrations of biomass burning OC (OCbb) are resolved by the extended Gelencsér method, with average contributions (to total OC) of 10.6 ± 1.7 % and 10.4 ± 1.5 % in winter at IAP and PG and 6.5 ± 5.2 % and 17.9 ± 3.5 % in summer, respectively. Correlations of water-insoluble OC (WINSOC) and water-soluble OC (WSOC) with POC and SOC showed that although WINSOC was the major contributor to POC, a non-negligible fraction of WINSOC was found in SOC for both fossil and non-fossil sources, especially during winter. In summer, a greater proportion of WSOC from non-fossil sources was found in SOC. Comparisons of the source apportionment results with those obtained from a chemical mass balance model were generally good, except for the cooking aerosol.

scholarly journals Fossil versus contemporary sources of fine elemental and organic carbonaceous particulate matter during the DAURE campaign in Northeast Spain

2011 ◽  
Vol 11 (8) ◽  
pp. 23573-23618 ◽  
Author(s):  
M. C. Minguillón ◽  
N. Perron ◽  
X. Querol ◽  
S. Szidat ◽  
S. M. Fahrni ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
Fine Particulate Matter ◽  
Western Mediterranean ◽  
Carbonaceous Aerosol ◽  
Carbonaceous Aerosols ◽  
Background Site

Abstract. We present results from the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean), with the objective of apportioning the sources of fine carbonaceous aerosols. Submicron fine particulate matter (PM1) samples were collected during February-March 2009 and July 2009 at an urban background site in Barcelona (BCN) and at a forested regional background site in Montseny (MSY). We present radiocarbon (14C) analysis for elemental and organic carbon (EC and OC) and source apportionment for these data. We combine the results with those from component analysis of aerosol mass spectrometer (AMS) measurements, and compare to levoglucosan-based estimates of biomass burning OC, source apportionment of filter data with inorganic+EC+OC speciation, submicron bulk potassium (K) concentrations, and gaseous acetonitrile concentrations. At BCN, 87 % and 91 % of the EC on average, in winter and summer, respectively, had a fossil origin, whereas at MSY these fractions were 66 % and 79 %. The contribution of fossil sources to organic carbon (OC) at BCN was 40 % and 48 %, in winter and summer, respectively, and 31 % and 25 % at MSY. The combination of results obtained using the 14C technique, AMS data, and the correlations between fossil OC and fossil EC imply that the fossil OC at Barcelona is ~65 % primary whereas at MSY the fossil OC is mainly secondary (~85 %). Day-to-day variation in total carbonaceous aerosol loading and the relative contributions of different sources predominantly depended on the meteorological transport conditions. The estimated biogenic secondary OC at MSY only increased by ~40 % compared to the order-of-magnitude increase observed for biogenic volatile organic compounds (VOCs) between winter and summer, which highlights the uncertainties in the estimation of that component. Biomass burning contributions estimated using the 14C technique ranged from similar to higher than when estimated using other techniques, and the different estimations were highly or moderately correlated. Differences can be explained by the contribution of secondary organic matter (not included in the primary biomass burning source estimates), and/or by an overestimation of the biomass burning OC contribution by the 14C technique if the estimated biomass burning EC/OC ratio used for the calculations is too high for this region. Acetonitrile concentrations correlate well with the biomass burning EC determined by 14C. K is a noisy tracer for biomass burning.

scholarly journals Wintertime aerosol chemistry and haze evolution in an extremely polluted city of the North China Plain: significant contribution from coal and biomass combustion

2017 ◽  
Vol 17 (7) ◽  
pp. 4751-4768 ◽  
Author(s):  
Haiyan Li ◽  
Qi Zhang ◽  
Qiang Zhang ◽  
Chunrong Chen ◽  
Litao Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Biomass Burning ◽  
Coal Combustion ◽  
North China Plain ◽  
North China ◽  
Biomass Combustion ◽  
The North ◽  
The North China Plain ◽  
Haze Pollution ◽  
Haze Episode

Abstract. The North China Plain (NCP) frequently experiences heavy haze pollution, particularly during wintertime. In winter 2015–2016, the NCP region suffered several extremely severe haze episodes with air pollution red alerts issued in many cities. We have investigated the sources and aerosol evolution processes of the severe pollution episodes in Handan, a typical industrialized city in the NCP region, using real-time measurements from an intensive field campaign during the winter of 2015–2016. The average (±1σ) concentration of submicron aerosol (PM1) during 3 December 2015–5 February 2016 was 187.6 (±137.5) µg m−3, with the hourly maximum reaching 700.8 µg m−3. Organic was the most abundant component, on average accounting for 45 % of total PM1 mass, followed by sulfate (15 %), nitrate (14 %), ammonium (12 %), chloride (9 %) and black carbon (BC, 5 %). Positive matrix factorization (PMF) with the multilinear engine (ME-2) algorithm identified four major organic aerosol (OA) sources, including traffic emissions represented by a hydrocarbon-like OA (HOA, 7 % of total OA), industrial and residential burning of coal represented by a coal combustion OA (CCOA, 29 % of total OA), open and domestic combustion of wood and crop residuals represented by a biomass burning OA (BBOA, 25 % of total OA), and formation of secondary OA (SOA) in the atmosphere represented by an oxygenated OA (OOA, 39 % of total OA). Emissions of primary OA (POA), which together accounted for 61 % of total OA and 27 % of PM1, are a major cause of air pollution during the winter. Our analysis further uncovered that primary emissions from coal combustion and biomass burning together with secondary formation of sulfate (mainly from SO2 emitted by coal combustion) are important driving factors for haze evolution. However, the bulk composition of PM1 showed comparatively small variations between less polluted periods (daily PM2. 5  ≤  75 µg m−3) and severely polluted periods (daily PM2. 5  >  75 µg m−3), indicating relatively synchronous increases of all aerosol species during haze formation. The case study of a severe haze episode, which lasted 8 days starting with a steady buildup of aerosol pollution followed by a persistently high level of PM1 (326.7–700.8 µg m−3), revealed the significant influence of stagnant meteorological conditions which acerbate air pollution in the Handan region. The haze episode ended with a shift of wind which brought in cleaner air masses from the northwest of Handan and gradually reduced PM1 concentration to  <  50 µg m−3 after 12 h. Aqueous-phase reactions under higher relative humidity (RH) were found to significantly promote the production of secondary inorganic species (especially sulfate) but showed little influence on SOA.

scholarly journals Wintertime aerosol chemistry and haze evolution in an extremely polluted city of North China Plain: significant contribution from coal and biomass combustions

2017 ◽  
Author(s):  
Haiyan Li ◽  
Qi Zhang ◽  
Qiang Zhang ◽  
Chunrong Chen ◽  
Litao Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Biomass Burning ◽  
Coal Combustion ◽  
North China Plain ◽  
North China ◽  
Bulk Composition ◽  
The North ◽  
Haze Pollution ◽  
Haze Episode ◽  
High Level

Abstract. The North China Plain (NCP) frequently encountered heavy haze pollution in recent years, particularly during wintertime. In 2015–2016 winter, the NCP region suffered several extremely severe haze episodes with air pollution red alerts issued in many cities. In this work, we investigated the sources and aerosol evolution processes of the severe pollution episodes in Handan, a typical industrialized city in the NCP region, using real-time measurements from an intensive field campaign during the winter of 2015–2016. The average (± 1σ) concentration of submicron aerosol (PM1) during December 3, 2015–February 5, 2016 was 187.6 (&amp;pm; 137.5) μg m−3, with the hourly maximum reaching 700.8 μg m−3. Organic was the most abundant component, on average accounting for 45 % of total PM1 mass, followed by sulfate (15 %), nitrate (14 %), ammonium (12 %), chloride (9 %) and BC (5 %). Positive matrix factorization (PMF) with multi-linear engine (ME-2) identified four major organic aerosol (OA) sources, including traffic emissions represented by a hydrocarbon-like OA (HOA, 7 % of total OA), industrial and residential burning of coal represented by a coal combustion OA (CCOA, 29 % of total OA), open and domestic combustion of wood and crop residuals represented by a biomass burning OA (BBOA, 25 % of total OA), and formation of secondary OA (SOA) in the atmosphere represented by an oxygenated OA (OOA, 39 % of total OA). Emissions of primary OA (POA), which together accounted for 61 % of total OA and 27 % of PM1, are a major cause of air pollution in this region during the winter. Our analysis further uncovered that, primary emissions from coal combustion and biomass burning together with secondary formation of sulfate (mainly from SO2 emitted by coal combustion) are important driving factors for haze evolution. However, the bulk composition of PM1 showed comparatively small variations between less polluted periods (daily PM2.5 &amp;leq; 75 μg m−3) and severely polluted periods (daily PM2.5 > 75 μg m−3), indicating relatively synchronous increases of all aerosol species during haze formation. The case study of a severe haze episode, which lasted 8 days starting with a steady build-up of aerosol pollution followed by a persistently high level of PM1 (326.7–700.8 μg m−3), revealed the significant influences of stagnant meteorological conditions on acerbating air pollution problems in the Handan region. The haze episode ended with a shift of wind which brought in cleaner air masses from the northwest of Handan and gradually reduced PM1 concentration to

scholarly journals Source apportionment of PM<sub>10</sub> in a North-Western Europe regional urban background site (Lens, France) using Positive Matrix Factorization and including primary biogenic emissions

2013 ◽  
Vol 13 (10) ◽  
pp. 25325-25385 ◽  
Author(s):  
A. Waked ◽  
O. Favez ◽  
L. Y. Alleman ◽  
C. Piot ◽  
J.-E. Petit ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Biomass Burning ◽  
Matrix Factorization ◽  
Iteration Process ◽  
Positive Matrix Factorization ◽  
Biogenic Emissions ◽  
Positive Matrix ◽  
Urban Background ◽  
Background Site ◽  
Urban Background Site

Abstract. In this work, the source of ambient particulate matter (PM10) collected over a one year period at an urban background site in Lens (France) were determined and investigated using a~Positive Matrix Factorization receptor model (US EPA PMF v3.0). In addition, a Potential Source Contribution Function (PSCF) was performed by means of the Hysplit v4.9 model to assess prevailing geographical origins of the identified sources. A selective iteration process was followed for the qualification of the more robust and meaningful PMF solution. Components measured and used in the PMF include inorganic and organic species: soluble ionic species, trace elements, elemental carbon (EC), sugars alcohols, sugar anhydride, and organic carbon (OC). The mean PM10 concentration measured from March 2011 to March 2012 was about 21 μg m−3 with typically OM, nitrate and sulfate contributing to most of the mass and accounting respectively for 5.8, 4.5 and 2.3 μg m−3 on a yearly basis. Accordingly, PMF outputs showed that the main emission sources were (in a decreasing order of contribution): secondary inorganic aerosols (28% of the total PM10 mass), aged marine emissions (19%), with probably predominant contribution of shipping activities, biomass burning (13%), mineral dust (13%), primary biogenic emissions (9%), fresh sea salts (8%), primary traffic emissions (6%) and heavy oil combustion (4%). Significant temporal variations were observed for most of the identified sources. In particular, biomass burning emissions were negligible in summer but responsible for about 25% of total PM10 and 50% of total OC at wintertime. Conversely, primary biogenic emissions were found to be negligible in winter but to represent about 20% of total PM10 and 40% of total OC in summer. The latter result calls for more investigations of primary biogenic aerosols using source apportionment studies, which quite usually disregards this type of sources. This study furthermore underlines the major influence of secondary processes during daily threshold exceedances. Finally, apparent discrepancies that could be generally observed between filter-based studies (such as the present one) and Aerosol Mass Spectrometer-based PMF analyses (organic fractions) are also discussed here.

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