The chemistry of the severe acidic precipitation in Shanghai, China

Abstract Seventy-six rain samples from forty-seven rain events and TSP aerosol samples throughout the entire year of 2005 were collected in Shanghai, China. The annual mean pH in rain was 4.49 with the lowest pH of 2.95, and the frequency of acid rain was 71% in 2005. The acidity of rain increased more than 15 times in the past 8 years compared to 1997. The volume-weighted mean ionic concentrations of the acidic ions, SO 4 2− and NO 3 − in rainwater were 199.59 and 49.80 μeq/L with maximum of 832.67 and 236.59 μeq/L, respectively. The concentration of SO 4 2− was higher than the most polluted cities abroad, indicating Shanghai has been a severe polluted city over the world. The high coal/fuel consumption from urbanization and the rapid increase of vehicles resulted in the high emission of SO 2 and NO x , the precursor of the high concentration of acidic ions, SO 4 2− and NO 3 − , which were the main reason of the severe acid rain in Shanghai. The major ions showed clear temporal variations with higher concentrations of SO 4 2− , NO 3 − , NH 4 + , and Ca 2+ in spring/winter, of Na + , Cl − , K + , and Mg 2+ in autumn, and the lowest of all the ions in summer. SO 4 2− and NO 3 − were mainly in the form of CaSO 4 and Ca(NO 3 ) 2 , which showed the dominant neutralization effect of Ca 2+ over NH 4 + . Source identification indicated that SO 4 2− , NO 3 − , NH 4 + and most Ca 2+ derived from anthropogenic sources, K + , Mg 2+ and partial Ca 2+ originated from mineral, and almost all the Cl − and Na + from the sea. The chemistry of precipitation in Shanghai was under the influence of local pollution sources and the long- and moderate-range transport through back trajectory analysis.

[1]  Kebin He,et al.  The water-soluble ionic composition of PM2.5 in Shanghai and Beijing, China , 2002 .

[2]  N. Nadkarni,et al.  CLOUD WATER AND PRECIPITATION CHEMISTRY IN A TROPICAL MONTANE FOREST, MONTEVERDE, COSTA RICA , 1998 .

[3]  Simultaneous Determination of Organic Acids,Methanesulfonic Acid and Inorganic Anions in Aerosol and Precipitation Samples by Ion Chromatography , 2003 .

[4]  H. Ueda,et al.  Model study on acidifying wet deposition in East Asia during wintertime , 2006 .

[5]  Jing Zhao,et al.  Low-carbon energy policy and ambient air pollution in Shanghai, China: a health-based economic assessment. , 2007, The Science of the total environment.

[6]  S. S. Srivastava,et al.  Characterization of precipitation at Agra , 1996 .

[7]  W. Winiwarter,et al.  Concentration of ionic compounds in the wintertime deposition: results and trends from the Austrian Alps over 11 years (1983–1993) , 1998 .

[8]  Trend of acid rain and neutralization by yellow sand in east Asia—a numerical study , 2002 .

[9]  A. Báez,et al.  Chemical composition of rainwater collected at a southwest site of Mexico City, Mexico , 2007 .

[10]  Haizhen Yang,et al.  Concentration and chemical composition of PM2.5 in Shanghai for a 1-year period , 2003 .

[11]  R. Sequeira,et al.  Small-scale spatial variability in the representative ionic composition of rainwater within urban Hong Kong , 1998 .

[12]  S. S. Srivastava,et al.  Investigation into atmospheric deposition through precipitation studies at New Delhi (India) , 1996 .

[13]  U. Kulshrestha,et al.  Influence of crustal aerosols on wet deposition at urban and rural sites in India , 2000 .

[14]  S. Tiwari,et al.  Fog and precipitation chemistry at Delhi, North India , 2004 .

[15]  S. Das,et al.  Chemical composition of rainwater and dustfall at bhubaneswar in the east coast of India , 2005 .

[16]  I. Beverland,et al.  The influence of meteorology and atmospheric transport patterns on the chemical composition of rainfall in south-east England , 1998 .

[17]  S. Kaspari,et al.  Major ionic composition of precipitation in the Nam Co region, Central Tibetan Plateau , 2007 .

[18]  F. Jeng,et al.  Precipitation chemistry in East Asia , 2000 .

[19]  P. Rao,et al.  Rain water and throughfall chemistry in the Silent Valley forest in south India , 1995 .

[20]  S. Tuncel,et al.  Rain water chemistry in Ankara, Turkey , 1996 .

[21]  S. Liu,et al.  The continuous field measurements of soluble aerosol compositions at the Taipei Aerosol Supersite, Taiwan , 2007 .

[22]  A. Báez,et al.  Chemical composition of precipitation at two sampling sites in Mexico: A 7-year study , 1997 .

[23]  O. Al-Khashman.  Study of chemical composition in wet atmospheric precipitation in Eshidiya area, Jordan , 2005 .

[24]  M. Whelan,et al.  Spatial patterns of throughfall and mineral ion deposition in a lowland Norway spruce (Picea abies) plantation at the plot scale , 1998 .

[25]  T. Okuda,et al.  Long-term trend of chemical constituents in precipitation in Tokyo metropolitan area, Japan, from 1990 to 2002. , 2005, The Science of the total environment.

[26]  Ying Zhang,et al.  Chemical compositions of wet precipitation and anthropogenic influences at a developing urban site in southeastern China , 2007 .

[27]  Jian Song,et al.  Toxicity and health effects of vehicle emissions in Shanghai , 2000 .

[28]  E. C. Teixeira,et al.  Atmospheric precipitation and chemical composition of an urban site, Guaíba hydrographic basin, Brazil , 2005 .

[29]  Danian Zhang,et al.  Characterization of major water-soluble inorganic ions in size-fractionated particulate matters in Shanghai campus ambient air , 2004 .

[30]  David G. Streets,et al.  Reductions in emissions of local air pollutants and co-benefits of Chinese energy policy: a Shanghai case study , 2006 .

[31]  M. Wendisch,et al.  Source identification during the great dun fell cloud experiment 1993 , 1997 .

[32]  M. Shao,et al.  Air concentrations and wet deposition of major inorganic ions at five non-urban sites in China, 2001–2003 , 2007 .

[33]  B. Lee,et al.  Chemical composition of precipitation and wet deposition of major ions on the Korean peninsula , 2000 .

[34]  S. Mohan,et al.  Rainwater chemistry at a regional representative urban site: influence of terrestrial sources on ionic composition , 2005 .

[35]  J. Erisman,et al.  Base cation deposition in Europe - Part II. Acid neutralization capacity and contribution to forest nutrition , 1997 .

[36]  N. Verhoest,et al.  A comparison of bulk and wet-only deposition at two adjacent sites in Melle (Belgium) , 2005 .

[37]  J. Tu,et al.  Trends in chemical composition of precipitation in Nanjing, China, during 1992–2003 , 2005 .

[38]  G. Tuncel,et al.  Ionic composition of precipitation at the Central Anatolia (Turkey) , 2001 .

[39]  Jiong Shu,et al.  Determining the sources of atmospheric particles in Shanghai, China, from magnetic and geochemical properties , 2001 .

[40]  Xingying Zhang,et al.  The ion chemistry；seasonal cycle；and sources of PM2.5 and TSP aerosol in Shanghai , 2006 .