scholarly journals Study on the Pollution Characteristics and Sources of Ozone in Typical Loess Plateau City

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 555
Author(s):  
Bin Li ◽  
Zhuangzhi Zhou ◽  
Zhigang Xue ◽  
Peng Wei ◽  
Yanjun Ren ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Loess Plateau ◽  
Ground Level ◽  
Photochemical Reactions ◽  
Oxides Of Nitrogen ◽  
Ozone Pollution ◽  
Pollution Characteristics ◽  
Nitric Oxide Concentration ◽  
Standard Value ◽  
High Level

Ground-level ozone is a secondary pollutant produced by photochemical reactions and it adversely affects plant and human health. Taiyuan City, a typical city on the loess plateau, is suffering from severe ozone pollution. We utilized the data from eight national environmental monitoring sites of Taiyuan, including concentrations of O3 and nitric oxide, and meteorological factors, such as air temperature and wind, to study the pollution characteristics and sources of ozone (O3) in Taiyuan in 2018. Results show that during 2018, the maximum value and 90th percentile of the maximum 8-h running average of O3 concentration were 257 μg/m3 and 192 μg/m3, respectively. There were 72 days where the O3 concentration exceeded the standard in 2018, which were mainly during April to August. The O3 concentration increased from March, reached a high level in April through August, and decreased significantly from September. The O3 concentrations displayed a typical “single peak” diurnal variation, which was high during the day with peak at around 13:00–15:00 and low at night. From April to August, the O3 concentrations at Jinyuan was the highest, followed by Xiaodian and Taoyuan, and the O3 concentrations at Shanglan and Nanzhai were the lowest. When the O3 concentration exceeded the standard value, Jinyuan contributed the most to the O3 pollution of Taiyuan, followed by Taoyuan and Xiaodian. High temperature and pressure, south and southwest winds can lead to an increase in O3 concentration. The O3 pollution in the Taiyuan urban area is caused by local generation, and the transportation of polluted air masses containing oxides of nitrogen (NOx) and volatile organic compounds (VOCs) emitted by industries, such as the coking and steel plants in counties of Jinzhong City in southern Taiyuan, and Qingxu County, and some counties in Lyuliang City to the southwest. In addition, the mountain winds and low nitric oxide concentration are the main reasons for the increase of O3 concentration, often observed in Shanglan at night.

scholarly journals Dominant patterns of summer ozone pollution in eastern China and associated atmospheric circulations

2019 ◽  
Vol 19 (22) ◽  
pp. 13933-13943 ◽  
Author(s):  
Zhicong Yin ◽  
Bufan Cao ◽  
Huijun Wang
Keyword(s):  
North China ◽  
Surface Ozone ◽  
Eastern China ◽  
Western Pacific Subtropical High ◽  
Ground Level ◽  
Photochemical Reactions ◽  
Western Pacific ◽  
Subtropical High ◽  
Ozone Pollution ◽  
Atmospheric Circulations

Abstract. Surface ozone has been severe during summers in the eastern parts of China, damaging human health and flora and fauna. During 2015–2018, ground-level ozone pollution increased and intensified from south to north. In North China and the Huanghuai region, the O3 concentrations were highest. Two dominant patterns of summer ozone pollution were determined, i.e., a south–north covariant pattern and a south–north differential pattern. The anomalous atmospheric circulations composited for the first pattern manifested as a zonally enhanced East Asian deep trough and as a western Pacific subtropical high, whose western ridge point shifted northward. The local hot, dry air and intense solar radiation enhanced the photochemical reactions to elevate the O3 pollution levels in North China and the Huanghuai region; however, the removal of pollutants was decreased. For the second pattern, the broad positive geopotential height anomalies at high latitudes significantly weakened cold air advection from the north, and those extending to North China resulted in locally high temperatures near the surface. In a different manner, the western Pacific subtropical high transported sufficient water vapor to the Yangtze River Delta and resulted in a locally adverse environment for the formation of surface ozone. In addition, the most dominant pattern in 2017 and 2018 was different from that in previous years, which is investigated as a new feature.

scholarly journals Volatile Organic Compound Analysis by Sorbent Tube-Thermal Desorption-Gas Chromatography: A Review

2018 ◽  
Vol 7 (3.14) ◽  
pp. 165
Author(s):  
Md Firoz Khan ◽  
Mazrura Sahani ◽  
Mohd Shahrul Mohd Nadzir ◽  
Lin Chin Yik ◽  
Hossain Mohammad Syedul Hoque ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Urban Areas ◽  
Ground Level ◽  
Ambient Air ◽  
Careful Consideration ◽  
Northeast Monsoon ◽  
Oxides Of Nitrogen ◽  
Ozone Pollution ◽  
Photochemical Pollution ◽  
Volatile Organic

Volatile organic compounds (VOCs) play an important role in the generation of ground level ozone and secondary organic aerosol. Most tropical countries such as Malaysia, Singapore, Indonesia, Brunei experience high ozone pollution. Beside ozone, oxides of nitrogen (NOx) from vehicular emissions also play an important role in photochemical pollution. NOx, particularly nitric oxide (NO), helps to ‘clean up’ ozone concentrations close to traffic in the ambient air of urban areas. Thus, knowledge of the chemistry of ozone-VOCs-NOx and finding the sources of VOCs are crucial to proceed with an appropriate mitigation strategy. Thus, the detection of ozone precursors and related VOCs is thoroughly discussed. This review finds that the inertness, hydrophobicity, and the effect of the artefact materials are very significant factors to be explored in the selection of the sorbent materials. In the SEA region, relative humidity is relatively high and exceeds 90% during the northeast monsoon. Thus, the hydrophobic properties of the sampling material need careful consideration. Further to the effect of relative humidity (RH), the artefact effect of the material itself is a challenge to be optimized and multi-sorbent material in a single tube could be a viable choice to minimize the effect of the unwanted signal in the spectrum.     

scholarly journals Spatial–Temporal Distribution Variation of Ground-Level Ozone in China’s Pearl River Delta Metropolitan Region

2021 ◽  
Vol 18 (3) ◽  
pp. 872
Author(s):  
An Zhang ◽  
Jinhuang Lin ◽  
Wenhui Chen ◽  
Mingshui Lin ◽  
Chengcheng Lei
Keyword(s):  
Ozone Concentration ◽  
Pearl River Delta ◽  
Temporal Distribution ◽  
Ground Level ◽  
Metropolitan Region ◽  
Pearl River ◽  
Ozone Pollution ◽  
Ground Level Ozone ◽  
Ozone Concentrations ◽  
The North

Long-term exposure to ozone pollution will cause severe threats to residents’ physical and mental health. Ground-level ozone is the most severe air pollutant in China’s Pearl River Delta Metropolitan Region (PRD). It is of great significance to accurately reveal the spatial–temporal distribution characteristics of ozone pollution exposure patterns. We used the daily maximum 8-h ozone concentration data from PRD’s 55 air quality monitoring stations in 2015 as input data. We used six models of STK and ordinary kriging (OK) for the simulation of ozone concentration. Then we chose a better ozone pollution prediction model to reveal the ozone exposure characteristics of the PRD in 2015. The results show that the Bilonick model (BM) model had the highest simulation precision for ozone in the six models for spatial–temporal kriging (STK) interpolation, and the STK model’s simulation prediction results are significantly better than the OK model. The annual average ozone concentrations in the PRD during 2015 showed a high spatial variation in the north and east and low in the south and west. Ozone concentrations were relatively high in summer and autumn and low in winter and spring. The center of gravity of ozone concentrations tended to migrate to the north and west before moving to the south and then finally migrating to the east. The ozone’s spatial autocorrelation was significant and showed a significant positive correlation, mainly showing high-high clustering and low-low clustering. The type of clustering undergoes temporal migration and conversion over the four seasons, with spatial autocorrelation during winter the most significant.

scholarly journals Winter Ozone Pollution in Utah’s Uinta Basin is Attenuating

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 4
Author(s):  
Marc L. Mansfield ◽  
Seth N. Lyman
Keyword(s):  
Ground Level ◽  
Ambient Air ◽  
Quality Standard ◽  
Ozone Pollution ◽  
Uinta Basin ◽  
Concentration Data ◽  
Previous Decade ◽  
High Concentrations ◽  
Ambient Air Quality Standard ◽  
Ozone Precursor

High concentrations of ground-level ozone have been observed during wintertime in the Uinta Basin of western Utah, USA, beginning in 2010. We analyze existing ozone and ozone precursor concentration data from 38 sites over 11 winter seasons and conclude that there has been a statistically significant (p < 0.02) decline in ozone concentration over the previous decade. Daily exceedances of the National Ambient Air Quality Standard for ozone (70 ppb) have been trending downward at the rate of nearly four per year. Ozone and NOx concentrations have been trending downward at the rates of about 3 and 0.3 ppb per year, respectively. Concentrations of organics in 2018 were at about 30% of their values in 2012 or 2013. Several markers, annual ozone exceedance counts and median ozone and NOx concentrations, were at their largest values in the period 2010 to 2013 and have never recovered since then. We attribute the decline to (1) weakening global demand for oil and natural gas and (2) more stringent pollution regulations and controls, both of which have occurred over the previous decade. We also see evidence of ozone titration when snow cover is absent.

Effect of round window membrane application of nitric oxide on hearing and nitric oxide concentration in perilymph

2003 ◽  
Vol 67 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Jonathan B. Hanson ◽  
Paul T. Russell ◽  
Andy T.A. Chung ◽  
Claire S. Kaura ◽  
Samantha H. Kaura ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Round Window ◽  
Round Window Membrane ◽  
Oxide Concentration ◽  
Nitric Oxide Concentration
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