南京市典型区域城市湿沉降污染成分特征分析

Contaminant properties analysis of wet precipitation in typical urban areas in Nanjing City

以南京市中心城区鼓楼区和城市郊区仙林地区为对象,对2009年12月至2011年7月每场降雨雨水进行水质监测和分析,研究城市湿沉降面源污染特征。结果显示:①研究区域雨水的主要污染成分为SO2-4、NO-3-N、TN和COD;②实验监测期内,鼓楼地区雨水中SO2-4、NO-3-N、TN和COD质量浓度均高于仙林地区雨水组分。其中,SO2-4质量浓度平均值62.79 mg/L,约是仙林地区平均值16.11 mg/L的4倍。③干湿周期对雨水水质影响显著。采集的雨水样本中,久未降雨后的首场雨水的COD、SO2-4质量浓度值高于相对连续降水后的雨水相关组分,但NO-3-N质量浓度低于连续性降水后的雨水组分。

In order to study the contaminant properties of wet precipitation in urban areas in Nanjing City, the chemical characteristics of rainwater were investigated from December 2009 to July 2011 at the Gulou campus and the Xianlin campus of Nanjing University, which are located in the downtown and suburban areas of Nanjing City, respectively. The results are as follows ： （ 1 ） The main contaminant components of rainwater in the two study areas were SO24- ,NO3-N,TN,COD. （2） During the monitoring period, the concentrations of SO42-, COD, TN, and NO3-N at the Gulou campus were higher than those at the Xianlin campus. The average concentration of SO^at the Gulou campus was 62.79 mg/L, four times that at the Xianlin campus, which had an average concentration of SO24 of 16. 11 mg/L. （3） The antecedent dry weather period had a remarkable effect on the rainwater quality. The concentrations of COD and SO24- in the rainwater from the first rainfall event after a long interval without rain were higher than those from continuous rainfall, but the concentration of NO3-N showed the opposite tendency.