Characterization of PM 2.5 and the major chemical components during a 1-year campaign in rural Guangzhou, Southern China

Lai, Senchao; Yan, Zhao; Ding, Aijun; Zhang, Yingyi; Song, Tao; Zheng, Junyu; Ho, Kin Fai; Lee, Shuncheng; Zhong, Lexuan

doi:10.1016/j.atmosres.2015.08.007

Cited by 114 publications

(60 citation statements)

References 39 publications

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“…The total concentration of WSII at three sites ranged from 72.2 to 100.0 µg m -3 with a mean of 84.3 µg m -3 (Table 3). Compared to other studies, the concentrations of WSII in PM 2.5 during the HPE were significantly higher Lai et al, 2016) -3 in PM 2.5 during HPE, respectively. These were 6.5, 3.9, 4.0, and 7.7 times higher, respectively, than those values measured during CD.…”

Section: Water Soluble Ionsmentioning

confidence: 46%

Chemical Characteristics of PM2.5 during a 2016 Winter Haze Episode in Shijiazhuang, China

Chen

Zhang

Zhu

et al. 2017

Aerosol Air Qual. Res.

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To better understand the chemical characteristics and the potential source regions of PM 2.5 measured from 18 January until 22 January 2016 in Shijiazhuang, China, PM 2.5 was measured continuously and integrated daily sampling using midvolume samplers was conducted at the three sites. The mean concentration of PM 2.5 at the three sites reached 113, 131 and 119 µg m -3 during the sampling period, the higher concentrations occurred at early morning and noon, similar variation trends were found in the three sites. The concentrations of OC were higher than EC at three sampling sites and the OC/EC ratios ranged from 9.09 to 12.4 with a daily mean value of 10.8 during a haze pollution episode (HPE), which suggested that carbonaceous compositions might be from same source. The total concentration of water soluble inorganic ions (WSII) at the sites ranged from 72.2 to 100.0 µg m -3 with a mean of 84.3 µg m -3. The dominant species were NO 3 -, SO 4 2-, NH 4 + , Cl -, accounting for 88.4% of the mean PM 2.5 WSII mass. The most abundant measured element was Na with average mass concentrations of 41.5, 37.0, and 38.1 µg m -3 during the HPE. Relative humidity during HPE was higher than during clean days with average values of 70.1% and 60.2%, suggesting that high relative humidity and low wind speed favored formation of secondary inorganic ions and accelerated hygroscopic growth. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) and a potential source contribution function (PSCF) analysis were used to assess the data. Back-trajectories for the three sites identified similar transport pathways. PSCF analysis showed a significant regional impact on PM 2.5 at Shijiazhuang during the polluted period. The potential source areas for PM 2.5 in Shijiazhuang were the Beijing-Tianjin region and Shandong Province. The results of the present study show the need for the development of PM 2.5 control measurements on a regional scale.

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Section: Water Soluble Ionsmentioning

confidence: 46%

Chemical Characteristics of PM2.5 during a 2016 Winter Haze Episode in Shijiazhuang, China

Chen

Zhang

Zhu

et al. 2017

Aerosol Air Qual. Res.

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“…Filter-based measurements of PM 2.5 at rural sites in China were limited and mainly conducted at Shangdianzi of Beijing, Conghua and Tianhu of Guangzhou, and Hok Tsui of Hong Kong (Hagler et al, 2006;Lai et al, 2016;Louie et al, 2005a;Zhao et al, 2013c). Rural PM 2.5 was around half of that in the cities of the same region.…”

Section: Geographical Distributionsmentioning

confidence: 99%

A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China

et al. 2017

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Abstract. To obtain a thorough knowledge of PM 2.5 chemical composition and its impact on aerosol optical properties across China, existing field studies conducted after the year 2000 are reviewed and summarized in terms of geographical, interannual and seasonal distributions. Annual PM 2.5 was up to 6 times the National Ambient Air Quality Standards (NAAQS) in some megacities in northern China. Annual PM 2.5 was higher in northern than southern cities, and higher in inland than coastal cities. In a few cities with data longer than a decade, PM 2.5 showed a slight decrease only in the second half of the past decade, while carbonaceous aerosols decreased, sulfate (SO 2− 4 ) and ammonium (NH + 4 ) remained at high levels, and nitrate (NO − 3 ) increased. The highest seasonal averages of PM 2.5 and its major chemical components were typically observed in the cold seasons. Annual average contributions of secondary inorganic aerosols to PM 2.5 ranged from 25 to 48 %, and those of carbonaceous aerosols ranged from 23 to 47 %, both with higher contributions in southern regions due to the frequent dust events in northern China. Source apportionment analysis identified secondary inorganic aerosols, coal combustion and traffic emission as the top three source factors contributing to PM 2.5 mass in most Chinese cities, and the sum of these three source factors explained 44 to 82 % of PM 2.5 mass on annual average across China. Biomass emission in most cities, industrial emission in industrial cities, dust emission in northern cities and ship emission in coastal cities are other major source factors, each of which contributed 7-27 % to PM 2.5 mass in applicable cities.The geographical pattern of scattering coefficient (b sp ) was similar to that of PM 2.5 , and that of aerosol absorption coefficient (b ap ) was determined by elemental carbon (EC) mass concentration and its coating. b sp in ambient condition of relative humidity (RH) = 80 % can be amplified by about 1.8 times that under dry conditions. Secondary inorganic aerosols accounted for about 60 % of aerosol extinction coefficient (b ext ) at RH greater than 70 %. The mass scattering efficiency (MSE) of PM 2.5 ranged from 3.0 to 5.0 m 2 g −1 for aerosols produced from anthropogenic emissions and from 0.7 to 1.0 m 2 g −1 for natural dust aerosols. The mass absorption efficiency (MAE) of EC ranged from 6.5 to 12.4 m 2 g −1 in urban environments, but the MAE of water-soluble organic carbon was only 0.05 to 0.11 m 2 g −1 . Historical emission control policies in China and their effectiveness were discussed based on available chemically resolved PM 2.5 data, which provides the much needed knowledge for guiding future studies and emissions policies.

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“…It confirms the validity of the gravimetric and chemical components analyses. More details of the concentrations of PM 2.5 and the major chemical components at TH and the comparison with other previous studies in the region refer to our recent publication (Table 1 and Table 2 in Lai et al (2016), respectively).…”

Section: Data Overviewmentioning

confidence: 99%

“…In the calculation, sulfate is assumed to be fully neutralized ammonium sulfate, nitrate is assumed to be in the form of ammonium nitrate, and OM is calculated by OC concentrations multiplying by a factor of 1.6 (Turpin and Lim, 2001;Lai et al, 2016). If there is inadequate ammonia in the atmosphere to fully neutralize sulfuric acid, ammoniated sulfate ion can be estimated from independent measurements of sulfate ion and ammonium ion as follows (Malm and Day, 2001;Tao et al, 2009) The visibility data were converted to b ext using Koschmeider equation (Horvath, 1971;Cheng et al, 2013):…”

Section: Reconstruction Of Pm 25 and Light Extinctionmentioning

confidence: 99%

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Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China

Chen

Lai

Gao

et al. 2016

Aerosol Air Qual. Res.

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A one-year campaign was conducted to collected PM 2.5 samples in the rural area of Guangzhou, the largest megacity in South China, from March 2012 to February 2013. Mass concentration of PM 2.5 , carbonaceous fractions (i.e., organic carbon (OC) and elemental carbon (EC)) and 6 water-soluble ions were analyzed. Light extinction coefficient (b ext ) of fine particulate matter was reconstructed using the revised IMPROVE formula at the site. (NH 4 ) 2 SO 4 (AS) made a dominant contribution to the light extinction budget, accounting for 61.3% (155.6 ± 108.5 Mm -1 ) annually, with highest in autumn (68.0%) and lowest in winter (55.2%). Organic matter (OM) was the second largest contributor accounting for 20.5% (52.2 ± 42.7 Mm -1 ) with highest in winter (23.4%) and lowest in spring (18.0%). The relationship between reconstructed b ext and measured b ext was investigated under the influence of seasonality, visibility and PM 2.5 concentration. We found that b ext could be reconstructed using revised IMPROVE formula in high PM 2.5 days (threshold value of ~60 µg m -3 ). On other hand, the performance of formula was unsatisfactory for b ext reconstruction of in low PM 2.5 days, when meteorological conditions could have significant impact on visibility.

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Characterization of PM 2.5 and the major chemical components during a 1-year campaign in rural Guangzhou, Southern China

Cited by 114 publications

References 39 publications

Chemical Characteristics of PM2.5 during a 2016 Winter Haze Episode in Shijiazhuang, China

Chemical Characteristics of PM2.5 during a 2016 Winter Haze Episode in Shijiazhuang, China

A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China

Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China

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Characterization of PM 2.5 and the major chemical components during a 1-year campaign in rural Guangzhou, Southern China

Cited by 114 publications

References 39 publications

Chemical Characteristics of PM2.5 during a 2016 Winter Haze Episode in Shijiazhuang, China

Chemical Characteristics of PM2.5 during a 2016 Winter Haze Episode in Shijiazhuang, China

A review of current knowledge concerning PM&lt;sub&gt;2. 5&lt;/sub&gt; chemical composition, aerosol optical properties and their relationships across China

Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China

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A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China