Characteristics and formation mechanisms of autumn haze pollution in Chengdu based on high time-resolved water-soluble ion analysis

2018 ◽  
Vol 26 (3) ◽  
pp. 2649-2661 ◽  
Author(s):  
Pan Wu ◽  
Xiaojuan Huang ◽  
Junke Zhang ◽  
Bin Luo ◽  
Jinqi Luo ◽  
...  
Keyword(s):  
Water Soluble ◽  
High Time ◽  
Formation Mechanisms ◽  
Time Resolved ◽  
Haze Pollution ◽  
Soluble Ion ◽  
Ion Analysis

scholarly journals Insight into winter haze formation mechanisms based on aerosol hygroscopicity and effective density measurements

2017 ◽  
Author(s):  
Yuanyuan Xie ◽  
Xingnan Ye ◽  
Zhen Ma ◽  
Ye Tao ◽  
Ruyu Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Growth ◽  
Water Soluble ◽  
Effective Density ◽  
Pollution Level ◽  
Formation Mechanisms ◽  
Haze Pollution ◽  
Haze Formation

Abstract. We characterize a representative haze event from a series of periodic particulate matter (PM) episodes that occurred in Shanghai during winter 2014. Particle size distribution, hygroscopicity, and effective density were measured online, along with analysis of water-soluble inorganic ions and single particle mass spectrometry. Regardless of pollution level, the mass ratio of SNA/PM1.0 (sulfate, nitrate, and ammonium) slightly fluctuated around 0.28 over the whole observation, suggesting that both secondary inorganic compounds and carbonaceous aerosols (including soot and organic matter) contributed substantially to the haze formation. Nitrate was the most abundant ionic species during hazy periods, indicating that NOx contributed more to haze formation in Shanghai than did SO2. The calculated PM concentration from particle size distribution displayed a variation pattern similar to that of measured PM1.0 during the representative PM episode, indicating that enhanced pollution level was attributable to the elevated number of larger particles. The number fraction of the near-hydrophobic group increased as the PM episode developed, indicating accumulation of local emissions. Three "banana-shape" particle evolutions were consistent with the rapid increase in PM1.0 mass loading, indicating rapid size growth by condensation of condensable materials was responsible for the severe haze formation. Both hygroscopicity and effective density of the particles increased considerably with growing particle size during the banana-shaped evolutions, indicating that secondary transformation of NOx and SO2 was a major contributor to the particle growth. Our results suggest that the accumulation of gas-phase and particulate pollutants under stagnant meteorological conditions and subsequent rapid particle growth by secondary processes, were primarily responsible for the haze pollution in Shanghai during wintertime.

scholarly journals Insight into winter haze formation mechanisms based on aerosol hygroscopicity and effective density measurements

2017 ◽  
Vol 17 (11) ◽  
pp. 7277-7290 ◽  
Author(s):  
Yuanyuan Xie ◽  
Xingnan Ye ◽  
Zhen Ma ◽  
Ye Tao ◽  
Ruyu Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Inorganic Compounds ◽  
Particle Growth ◽  
Water Soluble ◽  
Effective Density ◽  
Pollution Level ◽  
Formation Mechanisms ◽  
Haze Pollution ◽  
Shaped Particle ◽  
Haze Formation

Abstract. We characterize a representative particulate matter (PM) episode that occurred in Shanghai during winter 2014. Particle size distribution, hygroscopicity, effective density, and single particle mass spectrometry were determined online, along with offline analysis of water-soluble inorganic ions. The mass ratio of SNA ∕ PM1. 0 (sulfate, nitrate, and ammonium) fluctuated slightly around 0.28, suggesting that both secondary inorganic compounds and carbonaceous aerosols contributed substantially to the haze formation, regardless of pollution level. Nitrate was the most abundant ionic species during hazy periods, indicating that NOx contributed more to haze formation in Shanghai than did SO2. During the representative PM episode, the calculated PM was always consistent with the measured PM1. 0, indicating that the enhanced pollution level was attributable to the elevated number of larger particles. The number fraction of the near-hydrophobic group increased as the PM episode developed, indicating the accumulation of local emissions. Three banana-shaped particle evolutions were consistent with the rapid increase of PM1. 0 mass loading, indicating that the rapid size growth by the condensation of condensable materials was responsible for the severe haze formation. Both hygroscopicity and effective density of the particles increased considerably with growing particle size during the banana-shaped evolutions, indicating that the secondary transformation of NOx and SO2 was one of the most important contributors to the particle growth. Our results suggest that the accumulation of gas-phase and particulate pollutants under stagnant meteorological conditions and subsequent rapid particle growth by secondary processes were primarily responsible for the haze pollution in Shanghai during wintertime.

scholarly journals Importance of Ammonia Gas-Particle Conversion Ratio in Haze Formation in the Rural Agricultural Environment

2020 ◽  
Author(s):  
Jian Xu ◽  
Jia Chen ◽  
Na Zhao ◽  
Guochen Wang ◽  
Guangyuan Yu ◽  
...  
Keyword(s):  
Fine Particles ◽  
Critical Role ◽  
Conversion Ratio ◽  
Water Soluble ◽  
Formation Mechanisms ◽  
Ammonia Gas ◽  
Haze Pollution ◽  
Inorganic Species ◽  
High Ammonia ◽  
Haze Formation

Abstract. Ammonia in the atmosphere is essential for the formation of fine particles that impact air quality and climate. Despite extensive prior research to disentangle the relationship between ammonia and haze pollution, the role of ammonia in haze formation in the high ammonia emitted regions is still not well understood. Aiming to better understand secondary inorganic aerosol (SNA) formation mechanisms under high ammonia conditions, one-year hourly measurement of water-soluble inorganic species (gas and particle) was conducted in a rural supersite in Shanghai. Exceedingly high levels of agricultural ammonia, constantly around 30 μg m−3, were observed. We find that ammonia gas-particle conversion ratio (ACR), as opposed to ammonia concentrations, plays a critical role in SNA formation during the haze period. By assessing the effects of various parameters, including temperature (T), aerosol water content (AWC), aerosol pH, and activity coefficient, it seems that AWC plays predominant regulating roles for ACR. We propose a self-amplifying feedback mechanism associated with ACR for the formation of SNA, which is consistent with diurnal variations of ACR, AWC, and SNA. Our results imply that reduction of ammonia emissions alone may not reduce SNA effectively at least in rural agricultural sites in China.

scholarly journals Importance of gas-particle partitioning of ammonia in haze formation in the rural agricultural environment

2020 ◽  
Vol 20 (12) ◽  
pp. 7259-7269 ◽  
Author(s):  
Jian Xu ◽  
Jia Chen ◽  
Na Zhao ◽  
Guochen Wang ◽  
Guangyuan Yu ◽  
...  
Keyword(s):  
Fine Particles ◽  
Critical Role ◽  
Feedback Mechanism ◽  
Water Soluble ◽  
Formation Mechanisms ◽  
Haze Pollution ◽  
Inorganic Species ◽  
High Ammonia ◽  
Haze Formation

Abstract. Ammonia in the atmosphere is essential for the formation of fine particles that impact air quality and climate. Despite extensive prior research to disentangle the relationship between ammonia and haze pollution, the role of ammonia in haze formation in high ammonia-emitting regions is still not well understood. Aiming to better understand secondary inorganic aerosol (sulfate, nitrate, ammonium – SNA) formation mechanisms under high-ammonia conditions, 1-year hourly measurement of water-soluble inorganic species (gas and particle) was conducted at a rural supersite in Shanghai. Exceedingly high levels of agricultural ammonia, constantly around 30 µg m−3, were observed. We find that gas-particle partitioning of ammonia (ε(NH4+)), as opposed to ammonia concentrations, plays a critical role in SNA formation during the haze period. From an assessment of the effects of various parameters, including temperature (T), aerosol water content (AWC), aerosol pH, and activity coefficient, it seems that AWC plays predominant regulating roles for ε(NH4+). We propose a self-amplifying feedback mechanism associated with ε(NH4+) for the formation of SNA, which is consistent with diurnal variations in ε(NH4+), AWC, and SNA. Our results imply that a reduction in ammonia emissions alone may not reduce SNA effectively, at least at rural agricultural sites in China.

scholarly journals Vertical distribution of atmospheric particulate matters within urban boundary layer in southern China: size-segregated chemical composition and secondary formation through cloud processing and heterogeneous reactions

2019 ◽  
Author(s):  
Shengzhen Zhou ◽  
Luolin Wu ◽  
Junchen Guo ◽  
Weihua Chen ◽  
Xuemei Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Vertical Distribution ◽  
Aqueous Phase ◽  
Urban Boundary Layer ◽  
Water Soluble ◽  
Heterogeneous Reactions ◽  
Formation Mechanisms ◽  
Haze Pollution ◽  
Adverse Weather ◽  
Autumn And Winter

Abstract. Great progress has been made recently in the understanding of the sources and formation mechanisms of atmospheric aerosols at the ground level. However, vertical profiles and sources of size-resolved particulate matter within the urban boundary layer are still lacking. In this study, vertical distribution characteristics of size-segregated particles were investigated at three observation platforms (ground, 118 m and 488 m) on the 610-meter-high Canton Tower in Guangzhou, China. Size-segregated aerosol samples were simultaneously collected at the three levels on the Canton Tower in autumn and winter, respectively. Major aerosol components, including water-soluble ions, organic carbon and elemental carbon, were measured. The results showed that daily average fine-particle concentrations generally decreased with height. Concentrations of sulfate and ammonium in fine particles displayed small vertical gradients and nitrate concentrations increased with height in autumn, while the above chemical components showed greater variations in winter than in autumn. The size distributions of sulfate and ammonium in both seasons were characterized by dominant unimodal droplet modes with a peak at the size range of 0.44–1.0 μm. In autumn, the nitrate size distribution was bi-modal, peaking at 0.44–1.0 μm and 2.5–10 μm, while it was unimodal in winter, implying that the formation mechanisms for nitrate particles were different in the two seasons. Our results suggest droplet mode sulfate and nitrate are likely formed from aqueous-phase reactions and coarse mode nitrate formation is attributed to heterogeneous reactions of gaseous nitric acid on existing sea-derived coarse particles in autumn at the measurement site. The results from pollution cases study further showed that atmospheric aqueous-phase and heterogeneous reactions together with adverse weather conditions, such as temperature inversion and calm wind, resulted in the autumn and winter haze pollution in the PRD region.

High time-resolved characterization of airborne microbial community during a typical haze pollution process

2021 ◽  
pp. 125722
Author(s):  
Zhengsheng Xie ◽  
Shengli Du ◽  
Tianfeng Ma ◽  
Junli Hou ◽  
Xuelin Zeng ◽  
...  
Keyword(s):  
Microbial Community ◽  
High Time ◽  
Time Resolved ◽  
Haze Pollution

scholarly journals Effect of Different Pollution Parameters and Chemical Components of PM2.5 on Health of Residents of Xinxiang City, China

2021 ◽  
Vol 18 (13) ◽  
pp. 6821
Author(s):  
Shuang Wang ◽  
Mandeep Kaur ◽  
Tengfei Li ◽  
Feng Pan
Keyword(s):  
Particulate Matter ◽  
Carcinogenic Risk ◽  
Water Soluble ◽  
Chemical Components ◽  
Maximum Effect ◽  
Exposure Concentration ◽  
Soluble Ions ◽  
Haze Pollution ◽  
Water Soluble Ions ◽  
Blood Routine

The present study was planned to explore the pollution characteristics, health risks, and influence of atmospheric fine particulate matter (PM2.5) and its components on blood routine parameters in a typical industrial city (Xinxiang City) in China. In this study, 102 effective samples 28 (April–May), 19 (July–August), 27 (September–October), 28 (December–January) of PM2.5 were collected during different seasons from 2017 to 2018. The water-soluble ions and metal elements in PM2.5 were analyzed via ion chromatography and inductively coupled plasma–mass spectrometry. The blood routine physical examination parameters under different polluted weather conditions from January to December 2017 and 2018, the corresponding PM2.5 concentration, temperature, and relative humidity during the same period were collected from Second People’s Hospital of Xinxiang during 2017–2018. Risk assessment was carried out using the generalized additive time series model (GAM). It was used to analyze the influence of PM2.5 concentration and its components on blood routine indicators of the physical examination population. The “mgcv” package in R.3.5.3 statistical software was used for modeling and analysis and used to perform nonparametric smoothing on meteorological indicators such as temperature and humidity. When Akaike’s information criterion (AIC) value is the smallest, the goodness of fit of the model is the highest. Additionally, the US EPA exposure model was used to evaluate the health risks caused by different heavy metals in PM2.5 to the human body through the respiratory pathway, including carcinogenic risk and non-carcinogenic risk. The result showed that the air particulate matter and its chemical components in Xinxiang City were higher in winter as compared to other seasons with an overall trend of winter > spring > autumn > summer. The content of nitrate (NO3−) and sulfate (SO42−) ions in the atmosphere were higher in winter, which, together with ammonium, constitute the main components of water-soluble ions in PM2.5 in Xinxiang City. Source analysis reported that mobile pollution sources (coal combustion emissions, automobile exhaust emissions, and industrial emissions) in Xinxiang City during the winter season contributed more to atmospheric pollution as compared to fixed sources. The results of the risk assessment showed that the non-carcinogenic health risk of heavy metals in fine particulate matter is acceptable to the human body, while among the carcinogenic elements, the order of lifetime carcinogenic risk is arsenic (As) > chromium(Cr) > cadmium (Cd) > cobalt(Co) > nickel (Ni). During periods of haze pollution, the exposure concentration of PM2.5 has a certain lag effect on blood routine parameters. On the day when haze pollution occurs, when the daily average concentration of PM2.5 rises by 10 μg·m−3, hemoglobin (HGB) and platelet count (PLT) increase, respectively, by 9.923% (95% CI, 8.741–11.264) and 0.068% (95% CI, 0.067–0.069). GAM model analysis predicted the maximum effect of PM2.5 exposure concentration on red blood cell count (RBC) and PLT was reached when the hysteresis accumulates for 1d (Lag0). The maximum effect of exposure concentration ofPM2.5 on MONO is reached when the lag accumulation is 3d (Lag2). When the hysteresis accumulates for 6d (Lag5), the exposure concentration of PM2.5 has the greatest effect on HGB. The maximum cumulative effect of PM2.5 on neutrophil count (NEUT) and lymphocyte (LMY) was strongest when the lag was 2d (Lag1). During periods of moderate to severe pollution, the concentration of water-soluble ions and heavy metal elements in PM2.5 increases significantly and has a significant correlation with some blood routine indicators.

scholarly journals Characteristics of aerosol pollution during heavy haze events in Suzhou, China

2016 ◽  
Vol 16 (11) ◽  
pp. 7357-7371 ◽  
Author(s):  
Mi Tian ◽  
Huanbo Wang ◽  
Yang Chen ◽  
Fumo Yang ◽  
Xiaohua Zhang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Inorganic Ions ◽  
Weather Conditions ◽  
Water Soluble ◽  
Chemical Components ◽  
Formation Mechanisms ◽  
Visibility Impairment ◽  
Aerosol Pollution ◽  
Haze Formation ◽  
High Concentrations

Abstract. Extremely severe haze weather events occurred in many cities in China, especially in the east part of the country, in January 2013. Comprehensive measurements including hourly concentrations of PM2.5 and its major chemical components (water-soluble inorganic ions, organic carbon (OC), and elemental carbon (EC)) and related gas-phase precursors were conducted via an online monitoring system in Suzhou, a medium-sized city in Jiangsu province, just east of Shanghai. PM2.5 (particulate matter with an aerodynamic diameter of 2.5 µm or less) frequently exceeded 150 µg m−3 on hazy days, with the maximum reaching 324 µg m−3 on 14 January 2013. Unfavorable weather conditions (high relative humidity (RH), and low rainfall, wind speed, and atmospheric pressure) were conducive to haze formation. High concentrations of secondary aerosol species (including SO42−, NO3−, NH4+, and SOC) and gaseous precursors were observed during the first two haze events, while elevated primary carbonaceous species emissions were found during the third haze period, pointing to different haze formation mechanisms. Organic matter (OM), (NH4)2SO4, and NH4NO3 were found to be the major contributors to visibility impairment. High concentrations of sulfate and nitrate might be explained by homogeneous gas-phase reactions under low RH conditions and by heterogeneous processes under relatively high RH conditions. Analysis of air mass trajectory clustering and potential source contribution function showed that aerosol pollution in the studied areas was mainly caused by local activities and surrounding sources transported from nearby cities.

scholarly journals Occurrence of rubidium and cesium in Iqe coal, Qinghai-Tibet Plateau: Evidence from sequential chemical extraction experiment

2017 ◽  
Vol 35 (3) ◽  
pp. 376-387 ◽  
Author(s):  
Cunliang Zhao ◽  
Bangjun Liu ◽  
Jialiang Ma ◽  
Shiming Liu ◽  
Maksim G Blokhin
Keyword(s):  
Water Soluble ◽  
Tibet Plateau ◽  
Chemical Extraction ◽  
Silicate Minerals ◽  
Sequential Chemical Extraction ◽  
Qinghai Tibet Plateau ◽  
Extraction Experiment ◽  
Soluble Ion

The occurrence of Rb and Cs in coal samples from Iqe coalfield was analyzed by a sequential chemical extraction experiment. Five types of Rb and Cs were determined in the coal: water soluble, ion exchangeable, organic bonded, carbonate, and silicate. The results indicated that the occurrence of Cs is similar with Rb in coal, and nearly all Rb and Cs are distributed in silicate. The occurrence of Rb and Cs is most likely associated with silicate minerals in coal. With the high correlation between Rb, Cs, and K, and the high content of kaolinite and illite in these coal samples, it can be inferred that illite probably is the main carrier of Rb and Cs. Minor amounts of Rb and Cs may also be adsorbed by kaolinite in Iqe coal, and Cs may exist in other states, such as an exchangeable ion.

Sign in / Sign up

Export Citation Format

Share Document