Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9459758 | Atmospheric Research | 2005 | 16 Pages |
Abstract
In this study, variations of the chemical composition of precipitation in Nanjing, China, over a 12-year period (1992-2003) are presented. The average annual concentration of pH value was 5.15, ranging from 4.93 to 5.36, and there was no significant trend in the acidity of precipitation. SO42â, Clâ and NO3â were the main anions, while Ca2+, NH4+ and Mg2+ were the main cations. The concentrations of these main ions were very high compared to those reported in many other areas around the world. Most of the ions came from anthropogenic and crustal sources. High correlations were found among dust-derived cations Ca2+, Mg2+and K+, between Clâ and SO42â, between Clâ and NH4+ and between acidic anions and dust-derived cations, such as SO42â and Ca2+, SO42â and K+, Clâ and Ca2+, Clâ and K+, Fâ and Mg2+ and Fâ and K+. A significant decreasing trend was observed in concentration of SO42â because of the abatement strategies for SO2 emissions and energy policy change, while a significant increasing trend was found in the contribution of NO3â to acidification due to the rapidly growing number of motor vehicles. A significant decreasing trend was found in dust-derived cation Ca2+ due to more stringent controls of industrial dust emissions and rapid urbanization reducing the amount of open land, while the contribution of NH4+ to neutralization increased relatively.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Atmospheric Science
Authors
Jun Tu, Hesheng Wang, Zifan Zhang, Xin Jin, Wenqing Li,