TY - JOUR
T1 - Characterization of atmospheric ammonia over Xi'an, China
AU - Cao, Jun Ji
AU - Zhang, Ting
AU - Chow, Judith C.
AU - Watson, John G.
AU - Wu, Feng
AU - Li, Hua
PY - 2009/6
Y1 - 2009/6
N2 - Continuous measurements of atmospheric ammonia (NH3) between April 2006 and April 2007 were conducted at an urban site and a suburban site in Xi'an, northwest China. NH3 was collected using Ogawa passive samplers every sixth day. At the same time, NHL4+ in fine particles was collected using battery-powered mini-volume samplers. The annual average concentrations of NH3 were 12.9 μg/m3 and 14.1 μg/m3, at the urban and suburban sites, respectively. The NH 3 concentrations reached a maximum (∼22.8-35.3 M-g/m3) in June and July and were minimum (∼3.0-4.7 μg/m3) in December, which was closely linked with NH3 volatilization under different ambient temperatures. The seasonal variation in NH3 was summer > spring > autumn > winter at both sites, which may be ascribed to the impact of biological emission sources such as agricultural activity. NH3 and NFL4+ aerosol concentrations were weakly correlated, implying that gas-particle reactions are influenced by many factors such as sources, meteorology and removal. Average NH3/NH 4+ ratios varied from 0.1 to 25.3, with an annual average of 4.0. High NH3 concentrations at Xi'an had a significant influence on atmospheric acidity and the formation of secondary NH4+ aerosol.
AB - Continuous measurements of atmospheric ammonia (NH3) between April 2006 and April 2007 were conducted at an urban site and a suburban site in Xi'an, northwest China. NH3 was collected using Ogawa passive samplers every sixth day. At the same time, NHL4+ in fine particles was collected using battery-powered mini-volume samplers. The annual average concentrations of NH3 were 12.9 μg/m3 and 14.1 μg/m3, at the urban and suburban sites, respectively. The NH 3 concentrations reached a maximum (∼22.8-35.3 M-g/m3) in June and July and were minimum (∼3.0-4.7 μg/m3) in December, which was closely linked with NH3 volatilization under different ambient temperatures. The seasonal variation in NH3 was summer > spring > autumn > winter at both sites, which may be ascribed to the impact of biological emission sources such as agricultural activity. NH3 and NFL4+ aerosol concentrations were weakly correlated, implying that gas-particle reactions are influenced by many factors such as sources, meteorology and removal. Average NH3/NH 4+ ratios varied from 0.1 to 25.3, with an annual average of 4.0. High NH3 concentrations at Xi'an had a significant influence on atmospheric acidity and the formation of secondary NH4+ aerosol.
KW - Aerosol
KW - Agricultural activity
UR - https://www.scopus.com/pages/publications/67650938429
U2 - 10.4209/aaqr.2008.10.0043
DO - 10.4209/aaqr.2008.10.0043
M3 - 文章
AN - SCOPUS:67650938429
SN - 1680-8584
VL - 9
SP - 277
EP - 289
JO - Aerosol and Air Quality Research
JF - Aerosol and Air Quality Research
IS - 2
ER -