TY - JOUR
T1 - Characteristics of nitrogenous air pollutants at urban and suburban forested sites, Western Japan
AU - Chiwa, Masaaki
AU - Uemura, Tomotaka
AU - Otsuki, Kyoichi
AU - Sakugawa, Hiroshi
N1 - Funding Information:
Acknowledgments We acknowledge Hiroshima Prefecture for providing the NO and NO2 dataset recorded by the Hatsukaichi Monitoring Station. This work was partly supported by Grants-in-Aid for Scientific Research (no. 1820814 and 17380096) and for Young Scientists (no. 17780125) from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
PY - 2012/9
Y1 - 2012/9
N2 - Nitrogenous air pollutants including nitrogen dioxide (NO 2), nitric acid (HNO 3), nitrate (NO 3 -), ammonia (NH 3), ammonium (NH 4 +), and nitrous acid (HONO) were characterized at an urban forested (UF) site in Hiroshima and at a suburban forested (SF) site in Fukuoka, western Japan, using an annular denuder system for 1 year from May 2006 to May 2007 to compare the concentrations and chemical species of atmospheric nitrogenous pollutants between UF and SF sites. The proximity of the urban area was reflected in higher NO 2 concentrations at the UF site than at the SF site. NO 2 was more oxidized at the SF site because it is farther from an urban area than the UF site, which was reflected in higher concentrations of HNO 3 at the SF site than the UF site. HNO 3 and acidic sulfate is neutralized by NH 3, existing as ammonium nitrate (NH 4NO 3) and ammonium sulfate [(NH 4) 2SO 4] at the UF site. At the SF site, acidic sulfate is neutralized by NH 3, existing as (NH 4) 2SO 4, but NH4NO3, had scarcely formed at the SF site. A much higher HONO concentration was observed at the UF site than at the SF site, especially in winter and spring at night, which could be explained by higher NO 2 concentrations at the UF site because of its proximity to an urban area and stagnant meteorological conditions. Atmospheric HONO determination was critical in evaluating the possibility of damage to trees in UF areas.
AB - Nitrogenous air pollutants including nitrogen dioxide (NO 2), nitric acid (HNO 3), nitrate (NO 3 -), ammonia (NH 3), ammonium (NH 4 +), and nitrous acid (HONO) were characterized at an urban forested (UF) site in Hiroshima and at a suburban forested (SF) site in Fukuoka, western Japan, using an annular denuder system for 1 year from May 2006 to May 2007 to compare the concentrations and chemical species of atmospheric nitrogenous pollutants between UF and SF sites. The proximity of the urban area was reflected in higher NO 2 concentrations at the UF site than at the SF site. NO 2 was more oxidized at the SF site because it is farther from an urban area than the UF site, which was reflected in higher concentrations of HNO 3 at the SF site than the UF site. HNO 3 and acidic sulfate is neutralized by NH 3, existing as ammonium nitrate (NH 4NO 3) and ammonium sulfate [(NH 4) 2SO 4] at the UF site. At the SF site, acidic sulfate is neutralized by NH 3, existing as (NH 4) 2SO 4, but NH4NO3, had scarcely formed at the SF site. A much higher HONO concentration was observed at the UF site than at the SF site, especially in winter and spring at night, which could be explained by higher NO 2 concentrations at the UF site because of its proximity to an urban area and stagnant meteorological conditions. Atmospheric HONO determination was critical in evaluating the possibility of damage to trees in UF areas.
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U2 - 10.1007/s11270-012-1294-2
DO - 10.1007/s11270-012-1294-2
M3 - Article
AN - SCOPUS:84867331908
SN - 0049-6979
VL - 223
SP - 5473
EP - 5481
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
IS - 8
ER -