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Observation of chemical components of PM2.5 and secondary inorganic aerosol formation during haze and sandy haze days in Zhengzhou, China 被引量:9
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作者 Zhangsen Dong fangcheng su +1 位作者 Zhenya Zhang Shenbo Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2020年第2期316-325,共10页
Mineral dust particles play an important role in the formation of secondary inorganic aerosols, which largely contribute to haze pollution in China.During this study, a haze episode(haze days) and a typical haze proce... Mineral dust particles play an important role in the formation of secondary inorganic aerosols, which largely contribute to haze pollution in China.During this study, a haze episode(haze days) and a typical haze process mixed with sandstorm(sandy haze days)were observed in Zhengzhou with a series of high-time-resolution monitoring instruments from November 22 to December 8, 2018.Concentrations of PM10 and crustal elements clearly increased in the sandy haze days.Concentrations of gaseous pollutants, metallic elements emitted from anthropogenic sources, nitrate, and ammonium during sandy haze days were slightly lower than those during the haze days but still obviously higher than those during the non-haze days.The sulfate concentrations, the sulfate fractions in PM2.5,and the sulfur oxidation ratios significantly increased in the sandy haze days.Heterogeneous reactions dominated the conversion of SO2 during the haze and sandy haze days.Enhanced SO2 conversion during the sandy haze days may be attributed to the high concentrations of transition metal ions from the sandstorm when the values of relative humidity(RH) were in 30%–70%, and high O3 at certain time points.Gas-phase NO2 oxidation reactions were the main pathways for nitrate formation.In the sandy haze days,higher nitrogen oxidation ratio(NOR) at daytime may be associated with higher RH and lower temperature than those in the haze days, which facilitate the gas-to-particle partitioning of nitrate;higher NOR values at night may be attributed to the higher O3 concentrations, which promoted the formation of N2O5. 展开更多
关键词 SANDSTORM HAZE SULFATE AQUEOUS-PHASE reactions Transition metal ions
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Spatiotemporal characterization and regional contributions of O3 and NO2:An investigation of two years of monitoring data in Henan,China 被引量:7
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作者 Shijie Yu Shasha Yin +4 位作者 Ruiqin Zhang Lingling Wang fangcheng su Yixiang Zhang Jian Yang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2020年第4期29-40,共12页
To investigate the characteristics of ground level ozone(O3)for Henan Province,the ambient air quality monitoring data of 2015 and 2016 were analyzed.The result showed that the 8 h-max-O3 concentrations displayed a di... To investigate the characteristics of ground level ozone(O3)for Henan Province,the ambient air quality monitoring data of 2015 and 2016 were analyzed.The result showed that the 8 h-max-O3 concentrations displayed a distinct seasonality,where the maximum and minimum values,averaging 140.41,54.19μg/m3,occurred in summer and winter,respectively.There is a significant correlation between meteorological factors and O3 concentration.The Voronoi neighborhood averaging analysis indic ated that O3,temperature,and ultraviolet radiation in Henan province were decreased from northwest to southeast,while relative humidity and precipitation displayed the opposite trend.Besides meteorological factors,the chemical processes play an essential role in ozone formation.Reactions of NO,NO2 and O3 form a closed system,and the partitioning point of the OX-component(O3+NO2)was at 40 and 80μg/m3 for nitrogen oxide(NOx)in winter and summer,respectively,with NO2 dominating at higher NOx pollution and O3 being the m ajor component at lower levels.The relationship between oxidant(OX=O3+NO2)and NOx concentrations were evaluated to understand the regional and local contribution of OX.It showed that high regional contribution occurred in the spring,whereas the highest local contribution lead to the summer peak of O3 observed in Zhengzhou.This present study reveals important environment impacts from the photochemical process and the meteorological conditions in the region with better understanding on the O3 characterization. 展开更多
关键词 Ground-level ozone Meteorological parameter Photochemical oxidant Voronoi neighborhood averaging(VNA) Seasonal variation
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Chemical characteristics and source apportionment of PM_(2.5) between heavily polluted days and other days in Zhengzhou, China 被引量:24
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作者 Nan Jiang Qiang Li +5 位作者 fangcheng su Qun Wang Xue Yu Panru Kang Ruiqin Zhang Xiaoyan Tang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第4期188-198,共11页
PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual avera... PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM(2.5) pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days(daily PM32.5 concentrations &gt; 250 μg/mand visibility &lt; 3 km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM(2.5) and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources(i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry) of PM(2.5) were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode(Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM(2.5) in the study area was aggravated. 展开更多
关键词 PM2.5 Water soluble inorganic ions Secondary organic carbon CMB Back trajectory analysis
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