Abstract:The rainfalls had been collected from May 2009 to April 2010 at Chongming Dongtan National Wetland. The pH value, electrical conductivity and major water-soluble ions of rain samples were measured. Enrichment factors and backward trajectory analysis were used to identify the potential sources of inorganic ions. The results showed that the air quality of Chongming Dongtan was good with much lower concentrations of air pollutants. The volume-weighted pH value and electrical conductivity were 5.24 and 17.49μS/cm respectively, which indicated low pollution and acidity level. SO42? and NO3? were the major acidic anions, with the volume-weighted mean concentrations values of 52.27 and 21.39μeq/L respectively. NH4+ and Ca2+ were the major alkaline cations with volume-weighted mean concentrations were 33.36 and 27.13μeq/L, respectively. Source attributions of inorganic ions in rainwater indicated that Na+ and Cl? mainly derived from the seawater spray. NH4+ showed the dominant neutralization effect over Ca2+ and Mg2+, which suggested the main forms of the atmospheric particles were (NH4)2SO4, NH4HSO4 and NH4NO3. Back trajectory analysis implied that the precipitation was mostly affected by air mass from sea, in which the air mass from Northwest, Southwest China and Yangtze River Delta might bring large amounts of anthropogenic pollutions through long and moderate range transport, which resulted the acid rain events at Chongming Dongtan.
马琳, 杜建飞, 闫丽丽, 陈建民, 李想. 崇明东滩湿地降水化学特征及来源解析[J]. 中国环境科学, 2011, 31(11): 1768-1775.
MA Lin, DU Jian-Fei, YAN Li-Li, CHEN Jian-Min, LI Xiang. Chemical characteristics and source apportionment of precipitation at Dongtan Wetland, Chongming. CHINA ENVIRONMENTAL SCIENCECE, 2011, 31(11): 1768-1775.