scholarly journals Wet deposition of inorganic ions in 320 cities across China: spatio-temporal variation, source apportionment, and dominant factors

2019 ◽  
Vol 19 (17) ◽  
pp. 11043-11070 ◽  
Author(s):  
Rui Li ◽  
Lulu Cui ◽  
Yilong Zhao ◽  
Ziyu Zhang ◽  
Tianming Sun ◽  
...  
Keyword(s):  
Inorganic Ions ◽  
Northwest China ◽  
Yangtze River Delta ◽  
Water Soluble ◽  
Central China ◽  
Vehicle Ownership ◽  
Total Energy Consumption ◽  
Soluble Ions ◽  
Secondary Ions ◽  
The Mean

Abstract. The acid deposition has been considered to be a severe environmental issue in China. The pH, electrical conductivity (EC), and concentrations of water soluble ions (NO3-, Cl−, Ca2+, K+, F−, NH4+, Mg2+, SO42-, and Na+) in the precipitation samples collected from 320 cities during 2011–2016 across China were measured. The mean concentrations of F−, NO3-, and SO42- were in the order of winter (6.10, 19.44, and 45.74 µeq L−1) > spring (3.45, 13.83, and 42.61 µeq L−1) > autumn (2.67, 9.73, and 28.85 µeq L−1) > summer (2.04, 7.66, and 19.26 µeq L−1). Secondary ions (SO42-, NO3-, and NH4+) and F− peaked in the Yangtze River Delta (YRD) and Sichuan basin (SB). Crustal ions (i.e. Ca2+, Mg2+), Na+, and Cl− showed the highest concentrations in the semi-arid regions and the coastal cities. The statistical methods confirmed that the mean anthropogenic contribution ratios to SO42-, F−, NO3-, and NH4+ at a national scale were 46.12 %, 71.02 %, 79.10 %, and 82.40 %, respectively. However, Mg2+ (70.51 %), K+ (77.44 %), and Ca2+ (82.17 %) mostly originated from the crustal source. Both Na+ (70.54 %) and Cl− (60.42 %) were closely linked to sea salt aerosols. On the basis of the stepwise regression (SR) analysis, it was proposed that most of the secondary ions and F− were closely related to gross industrial production (GIP), total energy consumption (TEC), vehicle ownership, and N fertilizer use, but the crustal ions (Ca2+ and K+) were mainly controlled by the dust events. The influence of dust days, air temperature, and wind speed on ions increased from southeast China (SEC) to central China, and then to northwest China (NWC), whereas the influence of socioeconomic factors on acid ions (SO42- and NO3-) displayed the higher value in east China.

scholarly journals The wet deposition of the inorganic ions in the 320 cities across China: spatiotemporal variation, source apportionment, and dominant factors

2019 ◽  
Author(s):  
Rui Li ◽  
Lulu Cui ◽  
Yilong Zhao ◽  
Ziyu Zhang ◽  
Tianming Sun ◽  
...  
Keyword(s):  
Inorganic Ions ◽  
Northwest China ◽  
Yangtze River Delta ◽  
Water Soluble ◽  
Central China ◽  
Vehicle Ownership ◽  
Total Energy Consumption ◽  
Soluble Ions ◽  
Secondary Ions ◽  
The Mean

Abstract. The acid deposition has been considered to be a severe environmental issue in China. The pH, electrical conductivity (EC), and the concentrations of the water soluble ions (NO3−, Cl−, Ca2+, K+, F−, NH4+, Mg2+, SO42−, and Na+) in the precipitation samples collected from the 320 cities during 2011–2016 across the whole China were measured. The mean concentrations of F−, NO3− and SO42− were in the order of winter (6.10, 19.44 and 45.74 μeq/L) > spring (3.45, 13.83, and 42.61 μeq/L) > autumn (2.67, 9.73, and 28.85 μeq/L) > summer (2.04, 7.66, and 19.26 μeq/L). The secondary ions (SO42−, NO3− and NH4+), and F− peaked in Yangtze River Delta (YRD) and Sichuan basin (SB). The crustal ions (i.e., Ca2+, Mg2+), Na+, and Cl− showed the highest concentrations in the semi-arid regions and the coastal cities, respectively. The statistical methods confirmed that the mean anthropogenic contribution ratios to SO42−, F−, NO3−, and NH4+ at a national scale were 46.12 %, 71.02 %, 79.10 %, and 82.40 %, respectively. However, Mg2+ (70.51 %), K+ (77.44 %), and Ca2+ (82.17 %) were mostly originated from the crustal source. Both Na+ (70.54 %) and Cl− (60.42 %) were closely linked to the sea-salt aerosols. On the basis of the stepwise regression (SR) analysis, it was proposed that most of the secondary ions and F− were closely related to gross industrial production (GIP), total energy consumption (TEC), vehicle ownership, and N fertilizer use, but the crustal ions (Ca2+ and K+) were mainly controlled by the dust events. The influence of dust days, air temperature, and wind speed on ions increased from Southeast China (SEC) to Central China, and then to Northwest China (NWC), whereas the influence of socioeconomic factors on acid ions (SO42− and NO3−) displayed the higher value in East China.

scholarly journals Seasonal variations of water-soluble ions in PM10 at a WMO/GAW station in the Yangtze River Delta, China

2020 ◽  
Vol 194 ◽  
pp. 04058
Author(s):  
Dongqing Fang ◽  
Junli Jin ◽  
Wei Huang ◽  
Yong Zhang ◽  
Wanqi Sun ◽  
...  
Keyword(s):  
Yangtze River ◽  
Inorganic Ions ◽  
Yangtze River Delta ◽  
Water Soluble ◽  
The Yangtze River ◽  
Soluble Ions ◽  
Water Soluble Ions ◽  
Water Soluble Inorganic Ions ◽  
Oxidation Ratio ◽  
The Yangtze River Delta

In order to understand the seasonal levels, formation mechanism and atmospheric chemical behaviours of water-soluble ions of PM10 in the Yangtze River Delta (YRD) region, aerosol samples were collected from January 2nd to December 28th, 2017 at a WMO/GAW regional background station in Lin’an. The concentrations of PM mass and nine water-soluble inorganic ions were obtained. The annual average concentration of PM10 was 59.9±33.9 μg m−3, lower than those reported in previous studies, indicating air quality of YRD region was improved. Nine water-soluble inorganic ions was accounted for 30.2-45.1% of the total PM mass, while ammonium (NH4+), sulfate (SO42+), as well as nitrate (NO3-) were the major ions which contributed 86.3% to total ions. The NO3- concentration was lowest in summer but highest in winter, suggesting it was likely influenced by thermodynamics. The levels of SO42- in spring and winter were related to photochemical reaction and regional transportation. Except for the SNA, Ca2+ was highest in four seasons likely due to sand storm and road fugitive dust. The annual mean ratio of [NO3-]/[SO42-] was nearly to 1, indicating mobile and stationary sources were equally important in Lin’an. The mean nitrogen oxidation ratio (NOR) and sulfur oxidation ratio (SOR) were 0.22±0.13 and 0.41±0.13, respectively, suggesting secondary formation was significant in the atmosphere at the background station of YRD region.

scholarly journals Water-Soluble Ions in Atmospheric Aerosol Measured in a Semi-Arid and Chemical-Industrialized City, Northwest China

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 456
Author(s):  
Huimin Jiang ◽  
Zhongqin Li ◽  
Feiteng Wang ◽  
Xi Zhou ◽  
Fanglong Wang ◽  
...  
Keyword(s):  
Sulfur Oxidation ◽  
Northwest China ◽  
Water Soluble ◽  
Heterogeneous Reactions ◽  
Anthropogenic Source ◽  
Heating Period ◽  
Qinghai Province ◽  
Soluble Ions ◽  
Water Soluble Ions ◽  
Semi Arid

We investigated water-soluble ions (WSIs) of aerosol samples collected from 2016 to 2017 in Lanzhou, a typical semi-arid and chemical-industrialized city in Northwest China. WSIs concentration was higher in the heating period (35.68 ± 19.17 μg/m3) and lower in the non-heating period (12.45 ± 4.21 μg/m3). NO3−, SO42−, NH4+ and Ca2+ were dominant WSIs. The concentration of SO42− has decreased in recent years, while the NO3− level was increasing. WSIs concentration was affected by meteorological factors. The sulfur oxidation and nitrogen oxidation ratios (SOR and NOR) exceeded 0.1, inferring the vital contribution of secondary transformation. Meanwhile higher O3 concentration and temperature promoted the homogeneous reaction of SO2. Lower temperature and high relative humidity (RH) were more suitable for heterogeneous reactions of NO2. Three-phase cluster analysis illustrated that the anthropogenic source ions and natural source ions were dominant WSIs during the heating and non-heating periods, respectively. The backward trajectory analysis and the potential source contribution function model indicated that Lanzhou was strongly influenced by the Hexi Corridor, northeastern Qinghai–Tibetan Plateau, northern Qinghai province, Inner Mongolia Plateau and its surrounding cities. This research will improve our understanding of the air quality and pollutant sources in the industrial environment.

scholarly journals Two years of online measurement of fine particulate nitrate in the western Yangtze River Delta: influences of thermodynamics and N<sub>2</sub>O<sub>5</sub> hydrolysis

2018 ◽  
Vol 18 (23) ◽  
pp. 17177-17190 ◽  
Author(s):  
Peng Sun ◽  
Wei Nie ◽  
Xuguang Chi ◽  
Yuning Xie ◽  
Xin Huang ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Yangtze River ◽  
Nitrate Concentration ◽  
Yangtze River Delta ◽  
River Delta ◽  
Water Soluble ◽  
Online Measurement ◽  
High Concentration ◽  
Soluble Ions ◽  
Water Soluble Ions

Abstract. Particulate nitrate contributes a large fraction of secondary aerosols. Despite understanding of its important role in regional air quality and global climate, long-term continuous measurements are rather limited in China. In this study, we conducted online measurement of PM2.5 (particulate matter with diameters less than 2.5 µm) nitrate for 2 years from March 2014 to February 2016 using the Monitor for AeRosols and Gases in ambient Air (MARGA) in the western Yangtze River Delta (YRD), eastern China, and investigate the main factors that influenced its temporal variations and formation pathways. Compared to other sites in China, an overall high concentration of particulate nitrate was observed, with a mean value of 15.8 µg m−3 (0.5 to 92.6 µg m−3). Nitrate on average accounted for 32 % of the total mass of water-soluble ions and the proportion increased with PM loading, indicating that nitrate is a major driver of haze pollution episodes in this region. Sufficient ammonia drove most nitrate into the particle phase in the form of ammonium nitrate. A typical seasonal cycle of nitrate was observed, with the concentrations in winter on average 2 times higher than those in summer mainly due to different meteorological conditions. In summer, the diurnal variation of particulate nitrate was determined by thermodynamic equilibrium, resulting in a much lower concentration during daytime despite a considerable photochemical production. Air masses from the polluted YRD and biomass burning region contributed to the high nitrate concentration during summer. In winter, particulate nitrate did not reveal an evident diurnal variation. Regional transport from northern China played an important role in enhancing nitrate concentration. A total of 18 nitrate episodes were selected to understand the processes that drive the formation of high concentration of nitrate. Rapid nitrate formation was observed during the pre-episode (the day before nitrate episode day) nights, and dominated the increase of total water-soluble ions. Calculated nitrate from N2O5 hydrolysis was highly correlated to and accounted for 80 % of the observed nitrate, suggesting that N2O5 hydrolysis was a major contributor to the nitrate episodes. Our results suggested that rapid formation of nitrate could be a main cause for extreme aerosol pollution events in the YRD during winter, and illustrated the urgent need to control NOx emission.

scholarly journals Chemical Characteristics of Major Inorganic Ions in PM2.5 Based on Year-Long Observations in Guiyang, Southwest China—Implications for Formation Pathways and the Influences of Regional Transport

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 847
Author(s):  
Hao Xiao ◽  
Hua-Yun Xiao ◽  
Zhong-Yi Zhang ◽  
Neng-Jian Zheng ◽  
Qin-kai Li ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Inorganic Ions ◽  
Sulfur Oxidation ◽  
Average Concentration ◽  
Water Soluble ◽  
Soluble Ions ◽  
Water Soluble Ions ◽  
Transformation Mechanisms ◽  
Higher Temperature ◽  
Oxidation Ratio

Sulfate, nitrate and ammonium (SNA) are the dominant components of water-soluble ions (WSIs) in PM2.5, which are of great significance for understanding the sources and transformation mechanisms of PM2.5. In this study, daily PM2.5 samples were collected from September 2017 to August 2018 within the Guiyang urban area and the concentrations of the major WSIs in the PM2.5 samples were characterized. The results showed that the average concentration of SNA (SO42−, NO3−, NH4+) was 15.01 ± 9.35 μg m−3, accounting for 81.05% (48.71–93.76%) of the total WSIs and 45.33% (14.25–82.43%) of the PM2.5 and their possible chemical composition in PM2.5 was (NH4)2SO4 and NH4NO3. The highest SOR (sulfur oxidation ratio) was found in summer, which was mainly due to the higher temperature and O3 concentrations, while the lowest NOR (nitrogen oxidation ratio) found in summer may ascribe to the volatilization of nitrates being accelerated at higher temperature. Furthermore, the nitrate formation was more obvious in NH4+-rich environments so reducing NH3 emissions could effectively control the formation of nitrate. The results of the trajectory cluster analysis suggested that air pollutants can be easily enriched over short air mass trajectories from local emission sources, affecting the chemical composition of PM2.5.

scholarly journals Water-soluble inorganic ions in urban aerosols of the continental part of Balkans (Belgrade) during the summer – autumn (2008)

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Aleksandra Mihajlidi-Zelić ◽  
Dragana Đorđević ◽  
Dubravka Relić ◽  
Ivana Tošić ◽  
Ljubiša Ignjatović ◽  
...  
Keyword(s):  
Inorganic Ions ◽  
High Volume ◽  
Water Soluble ◽  
Data Sets ◽  
Hysplit Model ◽  
Air Masses ◽  
Average Mass ◽  
Aerosol Mass ◽  
Soluble Ions ◽  
Fine Mode

AbstractSize-segregated aerosol samples were collected using six stages High Volume Cascade Impactor. Aerosol mass and water soluble ions concentrations were determined. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to study the origin of air masses arriving to Belgrade in the investigated period. The obtained results of aerosol mass and water-soluble ion concentrations have been divided into six sub-data sets based on air mass categories. The highest average mass concentration of the fine mode (Dp ≤ 0.49 μm) was found for air masses coming to Belgrade from the southeast and northwest directions, and of the coarse mode (3.0 < Dp ≤7.2 μm) for air masses arriving from the northwest direction. The highest concentrations of SO

scholarly journals Characteristics of concentrations and chemical compositions for PM<sub>2.5</sub> in the region of Beijing, Tianjin, and Hebei, China

2013 ◽  
Vol 13 (1) ◽  
pp. 863-901 ◽  
Author(s):  
P. S. Zhao ◽  
F. Dong ◽  
D. He ◽  
X. J. Zhao ◽  
W. Z. Zhang ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Urban Areas ◽  
Motor Vehicle ◽  
Water Soluble ◽  
Photochemical Oxidation ◽  
Chemical Compositions ◽  
Soluble Ions ◽  
Secondary Ions ◽  
Water Soluble Ions ◽  
Autumn And Winter

Abstract. In order to study the temporal and spatial variations of PM2.5 and its chemical compositions in the region of Beijing, Tianjin, and Hebei (BTH), PM2.5 samples were collected at four urban sites in Beijing (BJ), Tianjin (TJ), Shijiazhuang (SJZ), and Chengde (CD) and one site at Shangdianzi (SDZ) regional background station over four seasons from 2009 to 2010. The samples were weighted for mass concentrations and analyzed in laboratory for chemical profiles of 19 elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sr, Ti, V, and Zn), eight water-soluble ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3−, and SO42−), and carbon fractions (OC and EC). The concentrations of PM2.5 and its major chemical species were season-dependent and showed spatially similar characteristics in the plain area of BTH. The average annual concentrations of PM2.5 were 71.8–191.2 μg m−3 at five sites, with more than 90 % sampling days exceeded 50 μg m−3 at BJ, TJ, and SJZ. PM2.5 pollution was most serious at SJZ, and the annual concentrations of PM2.5, secondary ions, OC, EC, and most of crustal elements were all highest. Due to stronger photochemical oxidation, the sum of concentrations of secondary ions (NH4+, NO3−, and SO42−) was highest in the summer at SDZ, BJ, TJ, and CD. Analysis of electric charges of water-soluble ions indicated the existence of nitric acid or hydrochloric acid in PM2.5. For all five sites, the concentrations of OC, EC and also secondary organic carbon (SOC) in the spring and summer were lower than those in the autumn and winter. Stable atmosphere and low temperatures appearing more frequently during autumn and winter facilitated the formation of SOC. The sums of crustal elements (Al, Ca, Fe, Mg, Ti, Ba, and Sr) were higher in the spring and autumn owing to more days with blowing or floating dust. The concentrations of heavy metals were at higher levels in the BTH area by comparison with other studies. In Shijiazhuang and Chengde, the PM2.5 pollution was dominated by coal combustion. Motor vehicle exhausts and coal combustion emissions both played important role in Tianjin PM2.5$ pollution. However, motor vehicle exhausts had played more important role in Beijing owing to the reduction of coal consumption and sharply increase of cars in recent years. At SDZ, regional transportation of air pollutants from southern urban areas was significant.

Characteristics of Water Soluble Ions in Atmospheric Aerosol on Clear and Hazy Days at Lin’an Regional Background Station, China

2011 ◽  
Vol 356-360 ◽  
pp. 2233-2238
Author(s):  
Hong Hui Xu ◽  
Jie Liu ◽  
Min Juan Mao ◽  
Jie Yao
Keyword(s):  
Atmospheric Aerosol ◽  
Yangtze River ◽  
Fine Particles ◽  
Yangtze River Delta ◽  
River Delta ◽  
Water Soluble ◽  
Coarse Particles ◽  
Regional Background ◽  
Soluble Ions ◽  
Water Soluble Ions

To investigate the characteristics of size distributions and water-soluble ions compositions of atmospheric aerosol in different weather conditions in the area of Yangtze River delta in China, aerosol samples were collected with Andersen cascade sampler on typical clear and hazy days at Lin’an regional background station. The water-soluble ionic concentrations were analyzed by the ion chromatography (IC). Results showed the concentrations of SO42-, NO3-, NH4+ and K+ on hazy days were 20.14, 17.45, 10.30, and 1.27µg m-3 in fine particles, respectively, and the concentrations of NO3-, NH4+ and K+ were 14.50, 2.35 and 0.50µg m-3 in coarse particles, respectively. This was 1.1-2.9 times higher than on clear days. The concentrations of Ca2+, Na+, Mg2+ and Cl- on hazy days were 2.67, 1.33, 0.37, and 1.03µg m-3 in fine particles, respectively, and the concentrations of Ca2+, Na+, Mg2+, Cl- and SO42- were 4.34, 1.27, 0.41, 0.89 and 2.08µg m-3 in coarse particles, respectively. This was 0.6-0.9 times lower than on clear days. K+ and secondary particles including sulfate, nitrate and ammonium came from the long-range transport which mainly from the area of Yangtze River delta, which was the main cause of formation of haze.

scholarly journals Characteristics of Particulate Matter at Different Pollution Levels in Chengdu, Southwest of China

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 990
Author(s):  
Yi Huang ◽  
Li Wang ◽  
Xin Cheng ◽  
Jinjin Wang ◽  
Ting Li ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fine Particles ◽  
Water Soluble ◽  
Pollution Levels ◽  
Mobile Sources ◽  
Soluble Ions ◽  
Particle Matter ◽  
Secondary Ions ◽  
Water Soluble Ions ◽  
Haze Episode

Air pollution is becoming increasingly serious along with social and economic development in the southwest of China. The distribution characteristics of particle matter (PM) were studied in Chengdu from 2016 to 2017, and the changes of PM bearing water-soluble ions and heavy metals and the distribution of secondary ions were analyzed during the haze episode. The results showed that at different pollution levels, heavy metals were more likely to be enriched in fine particles and may be used as a tracer of primary pollution sources. The water-soluble ions in PM2.5 were mainly Sulfate-Nitrate-Ammonium (SNA) accounting for 43.02%, 24.23%, 23.50%, respectively. SO42−, NO3−, NH4+ in PM10 accounted for 34.56%, 27.43%, 19.18%, respectively. It was mainly SO42− in PM at Clean levels (PM2.5 = 0~75 μg/m3, PM10 = 0~150 μg/m3), and mainly NH4+ and NO3− at Light-Medium levels (PM2.5 = 75~150 μg/m3, PM10 = 150~350 μg/m3). At Heavy levels (PM2.5 = 150~250 μg/m3, PM10 = 350~420 μg/m3), it is mainly SO42− in PM2.5, and mainly NH4+ and NO3− in PM10. The contribution of mobile sources to the formation of haze in the study area was significant. SNA had significant contributions to the PM during the haze episode, and more attention should be paid to them in order to improve air quality.

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