Aikawa,M., Hiraki,T., Mukai,H. and Murano,K.(2008): Characteristic variation of concentration and chemical form in sulfur, nitrate, ammonium, and chloride species observed at urban and rural sites of Japan. Water Air Soil Pollut., 190, 287-297.

『日本の都市域と農村域で観察された硫黄と硝酸とアンモニウムと塩化物の化学種の濃度と化学形の特徴的な変動』


Abstract
 A field survey on the concentration of chemical species in particulate matter and gaseous compounds at two monitoring sites with different site classifications (urban and rural) was conducted over three years. Total (particulate matter + gaseous compounds) concentrations at the rural site were significantly lower than those at the urban site for all species (sulfur (SO42-(p) and SO2(g)), nitrate (NO3-(p) and HNO3(g)), ammonium (NH4+(p)) and ammonia (NH3(g)), and chloride (Cl-(p) and HCl(g)), which is thought to reflect classification of the site. The difference in the sulfur concentration at the urban and rural sites was characterized by the difference in SO2 (g) concentration. Further, a clear seasonality was observed for the nitrate species. The HNO3 (g) concentration was high in the summer compared with other seasons at both the urban and rural sites. The NH4+ (p) concentration levels were approximately the same as those of NH3 (g) at both sites. The molar ratios of the particulate matter concentration to the total concentration showed different characteristics; the nitrate, ammonium and ammonia, and chloride species showed a clear seasonal variation: low in summer and high in winter and the values were similar regardless of the site. On the other hand, the sulfur species showed constant values at both the urban and rural sites, however the concentrations were significantly different for the two sites. Ammonium accounted for the largest proportion of cations in the particulate matter, regardless of the site classification. In contrast, SO42- (p) accounted for the largest proportion of anions at the rural site, whereas NO3- (p) was comparable to SO42- (p) at the urban site. Ammonia accounted for the largest proportion of all chemical species at both sites. Seasonal analysis of the proportional distribution in particulate matter and gaseous compounds provides information on atmospheric conditions.

Keywords: Ammonia; Ammonium; Filter pack; Nitrate; Nitric acid gas; Site classification; Sulfate; Sulfur dioxide』

1 Introduction
2 Experimental
 2.1 Monitoring site
 2.2 Sample collection and analysis
  2.2.1 Method and period
  2.2.2 Chemical and statistical analyses
3 Results and discussion
 3.1 Data assessment
 3.2 Concentrations of chemical species
  3.2.1 Sulfur species
  3.2.2 Nitrate species
  3.2.3 Ammonium and ammonia
  3.2.4 Chloride species
 3.3 Distribution of particulate matter and gaseous compounds
  3.3.1 Sulfur species
  3.3.2 Nitrate species
  3.3.3 Ammonium and ammonia
  3.3.4 Chloride species
 3.4 Proportional distribution in particulate matter and gaseous compounds
 3.5 Comparison of this survey with JELA survey
4 Conclusions
Acknowledgements
References


ホーム