Determination of Sulfamethoxazole Degradation Rate by an in Situ Experiment in a Reducing Alluvial Aquifer of the North China Plain

Abstract. Emission information is crucial for air quality modelling and air quality management. In this study, a new approach based on the understanding of the relationship between emissions and measured pollutant concentrations has been proposed to estimate pollutant emissions and source contributions. The retrieval can be made with single point in-situ measurements combined with backward trajectory analyses. The method takes into consideration the effect of meteorology on pollutant transport when evaluating contributions and is independent of energy statistics, therefore can provide frequent updates on emission information. The spatial coverage can be further improved by using measurements from several sites and combining the derived emission fields. The method was applied to yield the source distributions of black carbon (BC) and CO in the North China Plain (NCP) using in-situ measurements from the HaChi (Haze in China) Campaign and to evaluate contributions from specific areas to local concentrations at the measurement site. Results show that this method can yield a reasonable emission field for the NCP and can directly quantify areal source contributions. Major BC and CO emission source regions are Beijing, the western part of Tianjin and Langfang, Hebei, with Tangshan being an additional important CO emission source area. The source contribution assessment suggests that, aside from local emissions in Wuqing, Tianjin and Hebei S, SW (d < 100 km) are the greatest contributors to measured local concentrations, while emissions from Beijing contribute little during summertime.

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In situ continuous hourly observations of wintertime nitrate, sulfate and ammonium in a megacity in the North China plain from 2014 to 2019: Temporal variation, chemical formation and regional transport

Chemosphere ◽

10.1016/j.chemosphere.2020.127745 ◽

2021 ◽

Vol 262 ◽

pp. 127745 ◽

Cited By ~ 2

Author(s):

Miao Tang ◽

Yu Liu ◽

Jun He ◽

Zhe Wang ◽

Zhijun Wu ◽

...

Keyword(s):

Temporal Variation ◽

North China Plain ◽

North China ◽

Regional Transport ◽

The North ◽

The North China Plain

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Aerosol optical properties in the North China Plain during HaChi campaign: an in-situ optical closure study

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-5959-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 5959-5973 ◽

Cited By ~ 106

Author(s):

N. Ma ◽

C. S. Zhao ◽

A. Nowak ◽

T. Müller ◽

S. Pfeifer ◽

...

Keyword(s):

Optical Properties ◽

North China Plain ◽

North China ◽

Scattering Coefficient ◽

Aerosol Optical Properties ◽

Mean Values ◽

The North ◽

The North China Plain ◽

The Mean

Abstract. The largest uncertainty in the estimation of climate forcing stems from atmospheric aerosols. In early spring and summer of 2009, two periods of in-situ measurements on aerosol physical and chemical properties were conducted within the HaChi (Haze in China) project at Wuqing, a town between Beijing and Tianjin in the North China Plain (NCP). Aerosol optical properties, including the scattering coefficient (σsp), the hemispheric back scattering coefficient (σbsp), the absorption coefficient (σap), as well as the single scattering albedo (ω), are presented. The diurnal and seasonal variations are analyzed together with meteorology and satellite data. The mean values of σsp, 550 nm of the dry aerosol in spring and summer are 280±253 and 379±251 Mm−1, respectively. The average σap for the two periods is respectively 47±38 and 43±27 Mm−1. The mean values of ω at the wavelength of 637 nm are 0.82±0.05 and 0.86±0.05 for spring and summer, respectively. The relative high levels of σsp and σbsp are representative of the regional aerosol pollution in the NCP. Pronounced diurnal cycle of $σsp, σap and ω are found, mainly influenced by the evolution of boundary layer and the accumulation of local emissions during nighttime. The pollutants transported from the southwest of the NCP are more significant than that from the two megacities, Beijing and Tianjin, in both spring and summer. An optical closure experiment is conducted to better understand the uncertainties of the measurements. Good correlations (R>0.98) are found between the values measured by the nephelometer and the values calculated with a modified Mie model. The Monte Carlo simulation shows an uncertainty of about 30 % for the calculations. Considering all possible uncertainties of measurements, calculated σsp and σbsp agree well with the measured values, indicating a stable performance of instruments and thus reliable aerosol optical data.

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Determination of gaseous and particulate carbonyls (glycolaldehyde, hydroxyacetone, glyoxal, methylglyoxal, nonanal and decanal) in the atmosphere at Mt. Tai

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-2725-2013 ◽

2013 ◽

Vol 13 (1) ◽

pp. 2725-2758 ◽

Cited By ~ 2

Author(s):

K. Kawamura ◽

K. Okuzawa ◽

S. G. Aggarwal ◽

H. Irie ◽

Y. Kanaya ◽

...

Keyword(s):

North China Plain ◽

North China ◽

Time Resolved ◽

Quartz Filter ◽

Clear Sky ◽

Carbonyl Derivatives ◽

The North ◽

The North China Plain ◽

Upward Transport

Abstract. Gaseous and particulate semi-volatile carbonyl compounds were determined every three hours in the atmosphere of Mount Tai (elevation, 1534 m) in the North China Plain during 2–5, 23–24 and 25 June, 2006 under a clear sky condition. Using two-step filter cartridge in a series, particulate carbonyls were first collected on a quartz filter and then gaseous carbonyls were collected on a quartz filter impregnated with O-benzylhydroxylamine (BHA). After the two-step derivatization with BHA and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), carbonyl derivatives were measured using a gas chromatography. The gaseous concentrations were obtained as follow: glycolaldehyde (range 0–1271 ng m−3, average 555 ng m−3), hydroxyacetone (0–707 ng m−3, 163 ng m−3), glyoxal (198–1396 ng m−3, 720 ng m−3), methylglyoxal (410–3170 ng m−3, 1376 ng m−3), n-nonanal (0–236 ng m−3, 71 ng m−3), and n-decanal (0–159 ng m−3, 31 ng m−3). These concentrations are among the highest ever reported in the urban and forest atmosphere. We found that gaseous carbonyls are more than 10 times more abundant than particulate carbonyls. Time-resolved variations of carbonyls did not show any a clear diurnal pattern, except for hydroxyacetone. We found that glyoxal, methylglyoxal and glycolaldehyde positively correlated with levoglucosan (a tracer of biomass burning), suggesting that a contribution from field burning of agricultural wastes (wheat crops) is significant for the bifunctional carbonyls in the atmosphere of Mt. Tai. Upward transport of the pollutants to the mountaintop from the low lands in the North China Plain is a major process to control the distributions of carbonyls in the upper atmosphere over Mt. Tai.

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Aerosol optical properties in the North China Plain during HaChi campaign: an in-situ optical closure study

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-9567-2011 ◽

2011 ◽

Vol 11 (3) ◽

pp. 9567-9605 ◽

Cited By ~ 4

Author(s):

N. Ma ◽

C. S. Zhao ◽

A. Nowak ◽

T. Müller ◽

S. Pfeifer ◽

...

Keyword(s):

Optical Properties ◽

North China Plain ◽

North China ◽

Aerosol Optical Properties ◽

Mean Values ◽

The North ◽

The North China Plain ◽

The Mean ◽

Local Emissions

Abstract. The largest uncertainty in the estimation of radiative forcings on climate stems from atmospheric aerosols. In winter and summer of 2009, two periods of in-situ measurements on aerosol physical and chemical properties were conducted within the HaChi project at Wuqing, a town between Beijing and Tianjin in the North China Plain (NCP). Aerosol optical properties including scattering coefficient (σsp), hemispheric back scattering coefficient (σbsp), absorption coefficient (σap, as well as single scattering albedo (ω) are presented. The characteristics of diurnal and seasonal variations are analyzed together with the meteorological and satellite data. The mean values of σsp, 550 nm of the dry aerosol in winter and summer are 280 ± 253 and 379 ± 251 Mm−1, respectively. The average σap for the two periods are respectively 47 ± 38 and 43 ± 27 Mm−1. The mean values of ω are 0.83 ± 0.05 and 0.87 ± 0.05 for winter and summer, respectively. The relative high levels of σsp and σbsp are representative of the regional polluted aerosol of the North China Plain. Pronounced diurnal cycle of σsp, σap and ω are found, mainly influenced by the evolution of boundary layer and accumulation of local emissions during night-time. Regional transport of pollutants from southwest in the NCP is significant both in winter and summer, while high values of σsp and σap correlate with calm winds in winter, which indicating the significant contribution of local emissions. An optical closure experiment is conducted to better understand uncertainties of the measurements. Good correlations (R>0.98) are found between values measured by nephelometer and values calculated with a modified Mie model. Monte Carlo simulations show an uncertainty of about 30% for the calculations. Considering all possible uncertainties of measurements, calculated σsp and σbsp agree well with measured values, indicating a stable performance of instruments and thus a reliable aerosol optical data.

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