2007—2008年南京江北工业区大气降水化学特征

Chemical characteristics of precipitation in the industrial area to the north of the Yangtze River in Nanjing in 2007—2008

2007年3月—2008年9月在南京市江北地区南京信息工程大学采集有效降水样品共48个,测量了降水的pH值和电导率,用离子色谱仪分析检测了降水样品的阴、阳离子的质量浓度。结果表明:2007年的酸雨频率为44.5%,2008年酸雨频率为59.3%,南京江北工业区降水的酸性及酸化频率都有所增高;2007—2008年大气降水与2005—2006年所测数据相比较,NO3-的质量浓度略有增长,NH4+的质量浓度有了较大幅度的增长;研究区域SO42-/NO3-的实验数据表明,硫污染特征有所减弱,氮氧化物污染逐渐突出,表现出燃煤污染与汽车尾气污染并存的过渡型大气污染特征。

To understand the chemical composition and temporal variations of atmospheric precipitation to the north of the Yangtze River in Nanjing ,48 precipitation samples were collected and analyzed from March 2007 to September 2008. In the precipitation samples,44.5% in 2007 and 59.3% in 2008 were acidic. Compared with the data of 2005 and 2006, the acidity and acid rain frequency increased significantly;the mass concentration of NO3 had a slight increase and the mass concentration of NH; had a relatively obvious increase. The dominant atmospheric pollutant in this industrial area was SO2, mainly coming form coal burning and car exhaust. Comparison analysis showed that in recent years, the SO2s contribution to preciNtation acidity reduced while that of NOs enhanced markedly.